experimental - shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/86668/8/08chapter 2.pdf ·...

PART - II

EXPERIMENTAL

SECTION -1

TEMEPHOS

1.1 REVIEW

Temephos was first registered in the United States III 1965 by American

Cyanamid Company for a number of uses including citrus fruits, pet collars, and

mosquito control. A Registration Standard was issued in August, 1981. In response to

EPA's 1991 Data Call-In, American Cyanmid dropped all uses except the mosquito

larvicide use in non-potable waters and requested a low volume minor use waiver for

relief from the data requirements associated with that use. EPA found the waiver

justified on economic grounds and waived some of the requirements. In 1997, the

temephos technical registration was transferred to Clarke Mosquito Control Products,

Inc. The Agency has revoked all food tolerances for temephos. [See the Federal Register

(63 FR 5910) published on February 5,1998]

Abstract of the Disclosu re

The invention relates to a new class of sulfur containing diphenylene

organophosphates, their method of preparation, and insecticidal compositions containing

said organophosphates134•

This application is a continuation in part of application ser no. 287,190, filed on

June 12, 1963. '

In particular, this invention relates to a new class of sulfur containing

diphenylene organophosphate esters having the formula:

(X'h' A'~ OR" ~p/ /~

OR,n

61

Wherein A and A' are sulfur or oxygen and may be the same or different. B is S,

SO, or S02, X and Xl are halogen such as chlorine or bromine or lower alkyl, i.e.,

methyl, ethyl, propyl, isopropyl or butyl and may be the same or different, n and n' are

from ° to 2 and may be the same or different and R, R', R" and R'" are lower alkyl

and may be the same or different.

Compounds of this type described above may be prepared by reacting ·sulfur

diphenol of the formula

(X)n

~/-HO \ ;)

OH

in which B, X and n are the same as described above with an 0, 0' -di alkyl phosphoryl

halide selected from those of the formula:

A

Ro"-.,i p-y

R'O/

and

A' \ OR"

Y'-p/

"'-OR'"

and mixture thereof where R, R' , R" and R'" are lower alkyl and may be the same or

different and A and AI are sulfur or oxygen and may be the same or different and Y is

halogen.

The reaction is carried out on a relative mole basis of one mole of the diphenol to

2 moles of the phosphoryl halide, although an excess of the latter is sometimes

employed to advantage. The reaction is carried out under alkaline conditions in the

presence of a polar solvent such water, methyl ethyl ketone, or a like at temperatures of

between 0 and 100°C. The compounds of this invention may also be prepared in

solvents having a wide range of polarity employing a variety of methods to prevent the

accumulation of hydrogen halide by-product.

In preparing the diphenylene organophosphate of this invention, we have

discovered that solvent systems do oxert the substantial influence on the yield and "as

62

\

is" purity of the product. In this connection, we have determined that employing an

aqueous alkaline reaction medium (in lieu with an organic solvent medium such as

methyl ethyl ketone) having a pH of greater than 9 and normally of from about 9.5 to

about 14 and a temperature of from 20°C to about 80°C. (normally from 25°C to 60°C)

results in at least a 70% yield, though usually the yield is higher. As important as yield,

however, is that the product has a high "as is" purity. This is most 'important because the

compound, being of high molecular weight and generally liquid character, can not be

conveniently purified. Further of course the use of water as the solvent eliminates the

added cost of manufacture which results when use and recovery of organic solvent is

necessary.

While the compounds of this invention are adapted for various uses, including

use as petroleum additives, they have demonstrated important utility as a general

insecticide and particularly outstanding utility against insect larvae and other chewing

insects, whether they be in the larvae or adult stage.

As insecticides, they may be applied as dusts, sprays, emulsion, wettable

powders and hue like. As sprays they may be employed in organic solvents, such as

various ketones, e.g., acetone, cyclohexanone, isophorone and the. like. Additionally, as

sprays, . they may be employed with lower monohydric aliphatic alcohol, ketone

alcohols, such as diacetone alcohol and various esters and aromatic hydrocarbons. As

noted, they may be employed as emulsion in water or other non-solvents to which

suitable surfactants, wetting agents or emulsifying agents have been added. They may

be applied on solid carriers, such as tales and clays such as kaolin clay or fuller's earth,

or on such carriers as chalk, wood flour, . silica charcoal, activated carbon or other

powders. As a wettable powder, the compounds of this invention may be applied to

easily wettable carrier materials such as attaclay, with or without the aid of surfactants

or on less readily wettable carriers in combination with suitable surfactants.

In use, the compounds of this invention may be applied to the insect in

insecticidally effective amounts or an amount toxic to said insects, the term applied

63

I

~.

r

being intended to include application to their habitat or to organic matter, living or dead,

such as plant life, wool paper or wood, which forms the food of the insects. As will be

seen more fully here in after application of the sulfur co~taining diphenylene

organophosphate esters of this invention ·to larvae, as for example mosquito larvae in

their natural breeding grounds or the application to plant life which forms the feed of

chewing insects has been demonstrated to be a highly effective way of controlling

insects. Whether in the larvae or adult stage with respect to the control of mosquitoes

extensive programs employing, numerous types and kinds of compositions have been

used to control them, both in the larval and adult stages. Among the most successful

methods of control, yet discovered, is the method of spraying the breeding grounds with

materials capable of preventing mosquito larvae from maturing to adulthood. Presently,

available compositions used for this purpose have not been entirely satisfactory since

many of them are toxic to birds, fish and mammals which inhabit the breeding areas that

are treated. Under !)lese circumstances, extreme care must be taken when applying such

composition in order to avoid application of the dosages harmful to other inhabitants of

the area.

In this connection compounds of the instant invention are unique, for while they

are extremely toxic to mosquito'larvas in low concentrations, they are substantially non

toxic to fish, birds and mammalians at concentration many thousand times that of the

insecticidal dose.

As noted ,the compounds of this invention are highly effective insecticides when

used against insets which consume vegetation or other organic materials to which such

compounds are applied. Such insects are men's greatest competitor for food, damaging

and consuming enormous quantity of food annually. Typical of such insects are cabbage

worms, army worms, grass hoppers, Mexican bean beetles, colorado patato beetles.

European com borers and canker worms. In competing with man the growing or larval

stage is as a general rule, as destructive as the adult stage. In some groups such as the

lepidoptiera, the larva is the only form that does economic dam~ge. In other species,

only the adult stage is accountable for damage produced and in still others both the

64

larval and adult stages are responsible. The compounds of this invention have the

advantage of being highly effective against both stages of insect life.

The compounds of this invention have the further advantage that they may be

combined with other insecticides, which kill by contact action. Contact insecticides are

effective primarily against insects which suck plant juices without consuming the entire

tissue. The combination of two types of insecticides primarily effective against insect

having different feeding modes would provide insecticidal compositions effective for

the control of all type of insects. Thus, by way of example, the insecticides of this

invention may be advantageously combined with O,O-dimethyl S-(l,2-

dicarbethoxyethyl) phosphoro dithioate I-naphthyl N-methylcarbamate, pyrathrin mixed

esters of pyrethrolone and cinerolone keto-alcohols and two chrysanthenum acids,

Allethrin and O,O-dimethyl S (N-methylcarbamoyl) methyl phosporodithioate.

In order that the present invention may be more fully understood, the

following examples are give primarily by way of illustration. No specific details or

enumerations contained there in should be construed as limitations on the present

invention, except, insofar as they appear in the appended claims. All parts and

percentages are by weight unless otherwise specifically designated.

TEMEPHOS

Where R is Methyl or Ethyl and X is S or 502, were prepared and tested

against insect larvac. The title compound (la) a mosquito larvicide effective at

0.005 Ib.16/acre was substantially non-toxic to fish, birds and marrunals. 1, a

viscous oil; ND25 1.5883 was obtained in 91 % yield by adding 36 g (MeO)2 P {5) CI

to 12.4 g (p-HO C;H!)2 5 in 57 g 10% aqueous NaOH at PH-10-1l. The mixture was

65

stirred 4 hrs. at 40° C, 25% aqueous NaOH was added to maintain the pH. The

mixture was extracted with PhMe, dried and the solvent stripped to give 24g135.

(I) is prepared and can be used against prodenia eridenia; I (R=Me, X = 5)

can also be used against mites, Anopheles mosquitres, mosquito larvac, and

oncopeltus. Thus, a solution of 12.4 g (P-H00.H4)2 5 in 57 g 10% NaOH is

adjusted to pH 10-11, 36 g (MeO)2 P (5) Cl added, and the mixture kept 4 hrs at ==

40° to give 91 % 0, 0, 0', 0' - tetramethyl 0, 0' - thiodi - P - phenylene

phosphorothioate (II). ND25-1.5883136•

This compound is prepared by reacting 11 grams (0.05 mole) of 4, 4' -

thiodiphenol and 5.5 gram (0.1 mole) of sodium methoxide slurried in 400 ml. of

methyl ethyl ketone and refluxing for 15 minutes, distilling to remove methanol,

diluting with 100 ml. methyl ethyl ketone and adding 16.2 grams (0.11 mole) of 0,

0- di methyl phosphorochloridothioate dissolved in 50 ml. of methyl ethyl ketone

over 5 minutes under reflux. The mixture is then refluxed for 1.5 hours.

The solids are filtered and the solvent removed under reduced pressure.

The residue is dissolved in chloroform and the solution washed with 5% sodium

hydroxide, 5% hydrochloric acid, water and saturated sodium chloride solution.

The washed solution is then dried and concentrated under reduced pressure to

give 18.3 grams of oil. Purification by washing with hexane and chromatography

on acid washed alumina gives pure material n. sub D. sub 25 = 1.5880137•

0, 0, 0', 0' - Tetramethyl 0, 0' - 5ulfonylde P-phenulene phosphorithiate

is prepared by the following reaction in which 75 grams of 4, 4'-sulfonyl di phenol

was slurried in 300 ml H20. A solution of sodium hydroxide. Containing 1

equivalent of base in each 100 ml. of solution is prepared and 200 ml of this

solution is added to dissolved the phenol. Then 144 grams (0.9 mole) of 0, 0 -

66

dimethyl phosphorochloridothioate is added to the mixture over a period of 1.5

hours. The sodium hydroxide solution is added slowly to maintain a pH of 10.9 to

11.0. The mixture is heated to 40° C to complete the reaction and to hydrolyze the

excess 0, 0 - dimethyl phosphorochlaridothioate.

The product is filtered and dissolved in 300 ml benzene which was washed

with 100 ml of 5 % sodium hydroxide 100 ml of water and 100 ml saturated

solution chloride. The organic layer is dried with anhydrous magnesium sulfate

and the solvent removed in vacuum. The residue is then crystallized iron 200 ml

2B ethyl alcohol. A total of 13.5 gram is obtain melting paint 66-68° Cl34

1.2 TEMEPHOS PHYSICAL DATA

s

Temephos

NOMENCLATURE

Common name temephos (BSI, E-ISO, (m) F-ISO, ANSI, ESA).

IUPAC name 0, 0, 0', 0' -tetramethyl 0, O'-triodi-p-phenylene bis (phosphoro--thioate);

0,0,0', O'-tetramethyl 0, O'-triodi-p-phenyiene diphosphorothioate. -C. A. name 0, O'-(thiodi-4, 1-phenylene) bis(O, O'-dimethyl phosphorothioate).

CAS RN [3383-96-8J Development code AC 52 160. Official code OMS 786;

ENT27165.

67

PHYSICO-CHEMICAL PROPERTIES

Composition Technical grade is > 90% pure.

Mol. wt. 466.5 Mol. formula C16H2Q06P25.J

Form Colourless crystals; (tech., brown, viscous liquid). M.p. 30.0-30.5° C

SGjdensity 1.32(tech.) Kow 80900 Solubility In water 0.03 mgjl(25° C}.

Soluble in common organic solvents such as diethyl ether, aromatic and

chlorinated hydrocarbons. In hexane 9.6 gjl. Stability Hydrolysed by strong

acids and alkalis' (optimum stability is at pH 5 to pH 7). Do not store at

temperatures above 49° C.

COMMERCIALISATION

History Introduced by American Cyanamid Co. Patents BE 648531; GB 1039238;

US 3317636 Manufacturer Cyananmid.

APPLICATIONS

Mode of action Non-systemic insecticide. Cholinesterase inhibitor. Uses: Control

of larvae of Anopheles, Aedes, Culex, Simulium spp. etc., in public health and

agricultural situations. Also used for controlling fleas on dogs and cats, and lice on

humans.

Phytotoxicity Non-phytotoxic when used at the recommended application rates.

Formulation type EC; MG; GR; DP; Fumigant, SG, RB, KN, Fine grains.

CompaJilJility Incompatible \Y"ith alkaline substances.

Principal tradename ' Abate' (Cyanamid). Mixtures [temephos +] trichlorfon.

ANALYSIS

Product analysis by hplc (CIPAC Handbook, 1985, Ie, 2230, AOAC Methods, 1990,

982.97) or by glc a. Assoc. Off. Anal. Chern., 1982,65,454). Residues determined by

glc (N. R. Pasarela· & E. J. Orloski, Anal. Methods Pes tic. Plant Growth Regul., 1973,7,

119).

68

MAMMALIAN TOXICOLOGY

Acute oral LDso for male rats 4204 mg/kg, for females> 10,000 mg/kg.

Skin and eye Acute percutaneous LDso (24 hours) for rabbits 2181, rats> 4000

mg/kg. Non-irritating to eyes and skin. NOEL (2y) for rats 300 mg/kg diet.

Toxicity class: WHO Table 5; EPA III. Other No toxic symptom felt by humans

receiving 256 mg/man for 5 d, or 64 mg/man for 28 d (R. L. Laws et al., Environ,

Health, 1967, 14, 289).

ECOTOXICOLOGY

Birds Five-day dietary LCso for mallard ducks 1200, ring-necked pheasants 170

mg/kg diet. Fish LCso for rainbow trQut 31.8 mg/I. Bees Highly toxic by direct

contact; LCso (topical) 1.55 ~g/bee.

ENVIRONMENTAL FATE

Animals In mammals, elimination is mainly of unchanged temephos in the faeces

and urine. Other principal urinary metabolites are sulfate ester conjugates of 4, 4'

thiodiphenel, and 4,4'-sulfinyldiphenol, and 4,4'-sulfonyldiphenol (R. C. Blinn J.

Agric. Food Chern. 17. 188-122).

Plants In plants, oxidation to the sulfoxide, and, to a lesser extent, to the sulfone

and the mono-and di-orthophophates. further degradation proceeds very slowly.

Soil and water Soil absorption Freundlich K 73 (loamy sand), 130 (sandy loam).

244 (silt loam), 541 (loam).

69

1.3 COMMON PROCESS AND RAW MATERIAL

SPECIFICATION

TEMEPHOS

HO-{ }-si }-OH _N,-"a"",O","H,--_.~ Nao--{ }-si rONa Thio-Di Phentl

v

CHP,,~ s

P-.... -0 -0 " __ oCH) CH 0/ 0 ~ j s ~ j O-P, ) 'oc~

Temephose

Di methyl thiophosporus chloride DMTCL

A four necked flask (5 lit.) is fitted with condenser, overhead stirrer and funnel. A

thermometer is inserted through the fourth neck of solution of water (964 gm) in caustic

lye (47 %,170 gm.) was placed in the flask. The solution was stirred for 5 minutes at room

temperature. Thio di-phenol (TDP, 220 gm, 99 % purity, 1M) is added under stirring

condition. Solvent (toluene, 1200 ml) is under stirring condition. A mix solution oftriethyl

benzyl ammonium chloride (TEBA, 9.0 gm), tris ethylene diamine (TEDA, 2.25 gm) and

sodium carbonate (10.5 gm) in water (50 ml) is charged. The temperature of the contents

of the flask is raised to 40° C.

Dimethyl thiophosphorus chloride (DMTCl, 353.0 gm., 2.2 mole) was placed in the

funnel attached to the reaction flask and slowly added over four hours maintaining the

reaction temperature at 40° C. This is followed by addition of NaOH (200 ml, 2M) over a

period of two hours.

70

.. ~ The reaction mixture is cooked for 4 hours during which it is maintained at 40° C

and stirred continuously. During this period the reaction is monitored by gas

chromatography and checked for unreacted DMTCI (It should be less than 1 %).

On completion of the reaction organic layer is separated from aqueous layer. The

aqueous layer after proper treatment is discharged. The organic layer is successively

washed with methanol water (60:40,500 ml) and caustic solution (36 ml, 47%), methanol

water (50:40, 500 ml) and water (500 ml). After washing the solvent is distilled off. The

residual.solvent is recovered under vacuum at 65° C.

The product obtained is a light yellow liquid.

This is subjected to various means of purity checking.

The sample is checked for toluene per cent (by OC), moisture (by Karl-Fisher),

acidity (by titraction) and purity (Internal Standard Method HPLC).

Here, I have mentioned a standard method of operation. During this work I have

changed mole ration of reacting compounds, reaction temperature, solvent, pH and

Catalyst. The results obtained under different reaction conditions are described in Table

Nos. 1 to 15.

RAW MATERIAL SPECIFICATION OF TEMEPHOS

Toluene Appearance

Assay

B.P.

Sp.Or.

Benzene Appearance

Assay

B.P.

Sp. Or.

Colourless clear liquid

99%

109 to 110°C.

0.859 to 0.863


99%

78 to 82° C.

0.870 to 0.880

71

~. Xylene

Appearance Colourless clear liquid

Assay 99%

B.P. 138 to 1420 C.

Sp. Gr. 0.865 to 0.870

MDC


Assay 99%

B.P. 39 to 400 C.

Sp. Gr. 1.325

Thidiphenol

Appearance White crystal

.,. Assay 99%

M.P. 152 to 153 0 C.

DMTCI


Assay 99%

B.P. 66 to 670 C at 16 mm Hg.

Sp. Gr. 1.322

Caustic Lye


Assay 47 % minimum

Sp. Gr. 1.48

72

TEBA I TEDA

Appearance

Assay

White crystalline free flowing powder

99%

BA Chloride = Banzai Konium Chloride (50 % solution)

TBAB = Tri Benzyl Amonium Bromide (50 % solution)

Temephos

% purity = 90 % min. w / w.

Moisture content = 0.1 % max'. w/w.

Material insoluble in acetone = 0.5 % w / w max.

Specific gravity 25° C between = 1.32.

Temephos : 1kg. = 1000 Rs.

73

! ~ 1.4 EXPERIMENT DATA AND COST CALCULATION

1 . p f h tit f reparatIOn 0 temepl os usmg I eren so yen ~ro~or IOn: Raw Material & TDP:BENZENE

Sr. No. Parameters 1:1000 1:1500 1:1200 1:1500 1:2000

1 TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 165 165 165 133 165

3 Water (m!) 900 900 1014 1000 1014

4 Benzene (ml) 1000 1500 1200 1500 2000

5 TEBA (~ms) 9 9 9 9 9

6 TEDA(gms) 1.5 1.5 1.5 1.5 1.5

7 Na2C03 (gms) - - - . 10.7 -8 DMTCL(gms) 325 325 325 325 325

9 DMTCL Add. Time (hrs.) 4 4 4 4 4

10 DMTCL Add. Temp.(OC) 50 50 35 35 35

11 2N. NaOH (ml) 50 50 50 50 50

12 2N. Add. Temp (0C) 50 50 35 35 35

13 2N. Add. Time (hrs.) 2 2 2 2 2

14 Cooking Time (hrs.) 4 4 4 4 4

15 Cooking Temp. ("C) 50 50 35 35 35

16 %DMTCL 0.037 0.050 0.13 2.7 0.80

17 Vol. of Org. (ml) 1040 1450 1320 1220 2000

18 Wt. ofOrg. (gms) 994 1380 1260 1120 1820

19 Benzene recovered (ml) 850 1210 980 960 1650

20 Wt. of Product (gms) 290 260 210 230 320

21 % P ofTemephos 70.18 91.75 85 82 80.74

22 % Yield on TDP 62.17 55.73 45.02 49.30 68.50

23 % Yield on Purity 43.62 51.14 38.26 40.42 55.38

74

2. Preparation of temephos using different work up:

Sr. Raw M\lteriai & *same *same 4NNaoH 4NNaoH 1 NNaoH No. Parameters as as

I TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 165 165 170 170 170

3 Water (ml) 1014 . 1014 1014 1014 1014

4 MDC(ml) 1200 1200 1200 1200 1200 .

5 TEBA (gms) 9 9 9 . 9 9

6 TEDA(gms) 2.25 2.25 2.25 2.25 2.25

7 Na2C03 (gms) - - - - -8 DMTCL(gms) 337 353 337 353 353


10 DMTCL Add. Temp.(°C) 30-35· 40-42 40±2 40±2 40±2

I I 2N. NaOH (ml) 200 200 200 200 200

12 2N. Add. Temp (0C) 30-35 40-42 40±2 40 ±2 40±2

13 2N. Add. Time (hrs.) 2 2 2 2 2


15 Cooking Temp. ("C) 30-35 40-42 40±2 40±2 40±2

16 %DMTCL 0.12 0.15 0.006 0.23 0.14

17 Vol. of Org. (ml) 1160 1180 1165 1185 1195

18 Wt. ofOrg. (gms) 1500 1540 1510 1560 1570

19 MDC recovered (ml) 840 840 840 850 850

20 Wt. of Product (gms) 380 . 399 388 401 405 .

21 % P ofTemephos 92.24 92.28 89.67 90.30 88.32

22 % Yield on TDP 81.46 85.53 83.17 85.95 86.81

23. % Yield on Purity 75.13 78.92 74.58 77.62 76.65

* as described in the general procedure.

75

3. Miscellaneous

Temperature Mole ratio

Sr. No. Raw Material & CfDP:DMTC)

Parameters 45 35 5% less 5% excess TDP TDP

1 TDP (gms) 220 220 210 232

2 C.S. LYE (gms) 170 170 170 170

3 Water (ml) 1014 1014 1014 1014 .

4 Xylene (ml) 1200 1200 1200 1200

5 TEBA(gms) 9 9 9 9

6 TEDA(gms) 2.25 2.25 2.25 1.5

7 Na2C03 (gms) 10.5 10.5 10.5 10.5

8 DMTCL(gms) 353 353 353 353

9 DMTCL Add. Time (hrs.) 4 4 4 4

10 DMTCL Add. Temp.(DC) 45 35 40 40

11 2N. NaOH (ml) 200 200 200 200

12 2N. Add. Temp (DC) 45 35 40 40

13 2N. Add. Time (hrs.) 2 2 2 2

14 Cooking Time (hrs.) 4 5 5 4

15 Cooking Temp. ~C) 45 35 40 40

16 %DMTCL 0.30 1.04 0.89 0.23

17 Vol. of Org. (ml) 1320 1330 1320 1330

18 Wt. ofOrg. (gms) 1302 1305 1303 1305

19 Xylene recovered (ml) 1060 1065 1060 1058

20 Wt. of Product (gms) 368 367 350 374

21 % P ofTemephos 92.01 93.32 91.05 90.89

22 % Yield on TDP 78.88 78.67 78.60 76.01

23 % Yield' on Purity 72.58 73.41 71.56 69.84

76

l::t

4. Miscellaneous

Temperature Mole ratio Sr. Raw Material & . (TOP: OMTC) No. Parameters 45 35 5% less 5% excess

TOP TOP

1 TOP (gms) 220 220 210 232

2 C.S. LYE (gms) 170 170 170 170

3 Water (ml) 1014 1014 1014 1014

4 Toluene (ml) 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9

6 TEOA (gms) 2.25 2.25 2.25 2.25

7 Na2CO) (gms) 10.5 10.5 10.5 10.5

8 OMTCL (gms) 353 353 353 353

9 OMTCL Add. Time (hrs.) 4 4 4 4

10 OMTCL Add. Temp.(°C) 45 35 40 40

II 2N. NaOH (ml) 200 200 200 200

12 2N. Add. Temp (0C) 45 35 40 40

13 2N. Add. Time (hrs.) 2 2 2 2


15 Cooking Temp. (0C) 45 35 40 40

16 %OMTCL 0.30 1.04 0.92 0.23

17 Vol. of Org. (ml) 1320 1330 1324 1325

18 Wt. of Org. (gms) 1296 1308 1305 1303

19 Toluene recovered (ml) 1050 1065 1060 1055

20 Wt. of Product (gms) 367 365 351 373

21 % P of Temephos 91.55 93.49 91.65 92.49

22 % Yield on TOP 78.67 78.24 78.82 76.81

23 % Yield on Purity 72.02 73.14 72.24 70.11

77 +

5. Preparation of temephos using different solvent

Sr. Raw Material & Benzene MDe Xylene Toluene No. Parameters I TDP (gms) 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170

3 Water (ml) 1014 1014 1014 1014

4 Solvent (ml) 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9

6 TED A (gms) 2.25 2.25 2.25 2.25

7 Na2C03 (gms) 10.5 10.5 10.5 10.5

8 DMTCL(gms) 348 348 348 348

9 DMTCL Add. Time (hrs.) 4 4 4 4

10 DMTCL Add. Temp.(DC) 40 40 40 40

II 2N. NaOH (ml) 200 200 200 200

12 2N. Add. Temp (DC) 40 40 40 40

13 2N. Add. Time (hrs.) 2 2 2 2


15 Cooking Temp. ("C) 40 40 40 40

16 %DMTCL 0.19 0.18 0.16 0.23

17 Vol. of Org. (ml) 1310 1180 1340 1335

18 Wt. ofOrg. (gms) 1255 1560 1305 1308

19 Solvent recovered (ml) 1030 950 1055 1050

20 Wt. of Product (gms) 340 370 360 360

21 % P of Temephos 89.10 91.34 91.88 91.92

22 % Yield on TDP 72.88 79.31 77.17 77.17

23 % Yield on Purity 64.93 72.44 70.90 70.94

78

Cost Calculation:

TDP + 2NaOH + 2DMTCL -) Temephos + 2NaCI + 2H20 (Imp)

218.5 + 2 x 40 + 2 x 160.5 -) 466.5 + 2 x 58.5 + 2 x 18

Theoretical Input/output

220 + 80 + 321

Actual Input/output

220 + 112.8 + 348

Input Theoretical in gms. outputs in gms.

TDP 220 220/220 x 466.5

C.S. lye. : 240 (47 %) Water 2414

Toluene 1032

TEBA 9

TEDA 2.25

Na2CO) 10.5

DMTCL: 348

MeOH 477

Total : 4752.75

-) 466.5 + 117 + 37.5

-) 360 g. + 320.8

Actual outputs Yield on Theoretical in gms. Remarks

Temephos 360 360 1466.5 x 100 91.92 (%p) =77.17 Temephos 330.91 330.911466.5 x 100 Impurity 29.08 = 70.93 Toluene reco. 903

Toluene loss 129

Aq to efflux. : 2883.75

MeOH recov. 405 g

MeOH loss 72

Total : 4752.75

79

! .,.

Cost Calculation:

Bhavnagar University Libr:lfy,

BHAVNAGAR.

TOP + 2NaOH + 20MTCL ---> Temephos + 2NaCI + 2I-bO (Imp)

218.5 + 2 x 40 + 2 x 160.5 ---> 466.5 + 2 x 58.5 + 2 x 18

Theoretical: 611.11 +222.19 + 891.51 ---> 1295.83 + 429.21 Input/output

Actual :611.11 +313.34 + 966.67 ---> 1000g. + 891.11 Input/output

Input Theoretical Actual outputs Yield on Theoretical in gms. outputs in gms. in_gms. Remarks

TOP 611.11 611.111220 x 466.5 Temephos 1000 1000/1295.83 x 100 = 1295.83 91.92 (%p) =77.17

C.S. Lye: 666.67 Temephos 919.2 rI9.2!1295.83 x 100 (47 %) Impurity 80.8 = 70.93 Water : 6706.00 Toluene reeo. : 2508.00 Toluene: 2867.00 Toluene loss 359.00 TEBA 25.00 Aq to efflux. : 8010.87 TEO A .. 6.25 MeOH reeov.: 1125.00 Na2CO] : 29.17 MeOH loss 200 OMTCL: 966.67 MeOH : 1325.00 Total : 13202.87 Total : 13202.87

Raw material Cost (per kg) Consumption Actual cost

TOP 403.00 0.6111 246.27

C.S. lye 14.00 0.6666 9.33

Toluene 31.00 0.359 11.13

TEBA 120.33 0.025 3.00

TEOA 863.54 0.00625 5.40

Na2C03 14.00 0.0291 0.41

OMTCL 160.00 0.9666 154.65

Methanol 16.93 0.200 3.39

TOTAL 433.58

80

6. Preparation of temephos using different mole ratio.

Sr. Raw Material & TDP: DMTCL

No. Parameters 1:2 1:2.1 1:2.15 1:2.2 1:2.25

1 TOP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (ml) 1014 1014 1014 1014 1014

4 Xylene (m1) 1200 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9 9

6 TEOA (gms) 2.25 2.25 2.25 2.25 2.25

7 Na2C03 (gms) 10.5 10.5 10.5 10.5 10.5

8 OMTCL (gms) 321 337 345 353 361

9 OMTCL Add. Time (hrs.) 4 4 4 4 4

10 OMTCL Add. Temp.(DC) 40 40 40 40 40

11 2N. NaOH (ml) 200 200 200 200 200

12 2N. Add. Temp (DC) 40 40 40 40 40

13 2N. Add. Time (hrs.) 2 2 2 2 2


15 Cooking Temp. (DC) 40 40 40 40 40

16 %OMTCL 0.081 0.12 0.44 1.15 1.82

17 Vol. of Org. (m1) 1325 1340 1360 1340 1350

18 Wt. ofOrg. (gms) 1260 1303 1315 1312 1310

19 Xylene recovered (ml) 1050 1050 1055 1065 1045 .-

20 Wt. of Product (gms) 326 339 349 365 362

21 % P of Temephos 89.50 93.20 92.28 89.23 86.32

22 % Yield Ol). TOP 69.88 72.66 74.81 78.24 77.60

23 % Yield on Purity 62.54 67.72 69.03 69.81 66.98

81

7. Preparation of temephos using different mole ratio.

Sr. Raw Material & TDP: DMTCL

No. Parameters 1 :2 1 :2.1 1:2.15 1:2.2 1:2.25

I TOP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (m!) 1014 1014 1014 1014 1014

4 Toluene (ml) 1200 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9 9

6 TEO A (gms) 2.25 2.25 2.25 2.25 2.25

7 Na2CO) (gms) 10.5 10.5 10.5 10.5 10.5

8 OMTCL(gms) 321 337 345 353 361


10 OMTCL Add. Temp.("C) 40 40 40 40 40

II 2N. NaOH (ml) 200 200 200 200 200

12 2N. Add. Temp (0C) 40 40 40 40 40

13 2N. Add. Time (hrs.) 2 2 2 2 2


15 Cooking Temp. (0C) 40 40 40 40 40

16 %OMTCL 0.098 0.11 0.45 1.1 1.86

17 Vol. ofOrg. (m1) 1315 1335 1360 1370 1345

18 Wt. ofOrg. (gms) 1255 1295 1318 1314 1308

19 Toluene recovered (ml) 1050 1050 1055 1065 1045

20 Wt. of Product (gms) 325 338 350 367 362

21 % P of Temephos 89.24 93.4 91.23 89.56 86.24

22 % Yield on TOP 69.66 72.45 75.02 78.67 77.60

23 % Yield on Purity 62.17 67.67 68.44 70.45 66.92

82

Cost Calculation:

TDP + 2NaOH + 2DMTCL -> Temephos + 2NaCl + 2H20 (Imp)

218.5 + 2 x 40 + 2 x 160.5 -> 466.5

Theoretical : 220 + 80 + 321 Input/output

Actual Input/output

: 220 + 112.8 + 353

-> 466.5

-> 367 g.

+ 2 x 58.5 + 2 x 18

+ 117 + 37.5

+ 318.8

Input Theoretical Actual outputs Yield on Theoretical in gms. outputs in gms. in gms. Remarks

TDP 220 220/220 x 466.5 Temephos 367 367/466.5 x 100 89.56 (%p) = 78.67

C.S. lye. : 240 Temephos 328.67 328.691466.5 x 100 (47 %) Impurity 38.31 = 70.45 Water 2414 Toluene reco. 915.9

Toluene 1032 Toluene loss 116.1

TEBA 9 Aq to efflux. : 2881.75

TEDA 2.25 MeOH recov. 405 g

Na2CO) 10.5 MeOH loss 72

DMTCL: 353

MeOH 477

Total : 4757.71 Total : 4757.71

83

Cost Calculation:

TOP + 2NaOH + 20MTCL ~ Temephos + 2NaCI + 2H20 (Imp)

218.5 + 2 x 40 + 2 x 160.5 ~ 466.5 + 2 x 58.5 + 2 x 18

Theoretical : 599.46 + 217.98 + 874.00 ~ 1271.12 + 420.32 Input/output

Actual : 599.46 + 307.36 + 961.85 ~ 1000 g. + 868.67 Input/output

Input Theoretical Actual outputs Yield on in gms. outputs in gms. in gms. Theoretical

Remarks TOP 599.46 599.46/220 x 466.5 Temephos 1000 100011271.12 x 100

= 1271.12 89.56 (%p) = 78.67 C.S. Lye: 653.95 Temephos 895.6 895.6/1271.12 xlOO (47 %) Impurity 104.4 = 70.45 Water 6578.00 Toluene reco. : 2495.00 Toluene : 2812.00 Toluene loss 317.00 TEBA 24.45 Aq to efflux. : 7852.65 TEO A 6.13 MeOH recoy. : 1104 Na2CO] : 28.61' MeOH loss 196 OMTCL: 961.85 MeOH : 1300.00 Total : 12964.65 Total : 12964.65


TOP 403.00 0.5996 241.63

C.S. lye 14.00 0.6539 9.15

Toluene 31.00 0.317 9.83

TEBA 120.33 0.0244 2.94

TEO A 863.54 0.00613 5.29

Na2C03 14.00 0.0281 0.39

OMTCL 160.00 0.9618 153.89

Methanol 16.93 0.1960 3.32

TOTAL 426.44

84

,

8. Preparation of temephos using at different pH.

Sr. Raw Material & ~H

No. Parameters 9.5 to 10.5* 11 to 11.5 11.5 to 12 12 to 14 12 to 14

1 TOP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 l70 l70 170 170

3 Water (ml) 1014 1014 1014 1014 1014

4 Xylene (ml) 1200 1200 1200 1200 1200

5 TEBA (gl11s) 9 9 9 9 ·9

6 TEOA (gms) 2.25 2.25 2.25 2.25 2.25

7 NaZC03 (gms) 10.5 10.5 10.5 10.5 10.5

8 OMTCL(gms) 337 337 337 337 353


10 DMTCL Add. Temp.(OC) 40 40 40 40 40

II 2N. NaOH (ml) 200 180 190 210 230

12 2N. Add. Temp (0C) 40 40 40 40 40

13 2N. Add. Time & Cooking 16 12 8 6 6 Time (hrs.)

14 Cooking Temp. (0C) 40 40 40 40 40

15 %OMTCL 0.6 0.68 0.22 0.38 0.22

16 Vol. ofOrg. (ml) 1160 1280 1325 1350 1370

17 Wt. ofOrg. (gms) 1130 1235 1290 1310.5 1331

18 Xylene recovered (ml) 1040 1060 1060 1060 1065

19 Wt. of Product (gms) 116.8 266 328 342 388

20 % P of Temephos 83.28 88.72 91.00 92.53 93.63

21 % Yield on TOP 25.04 57.02 70.31 73.31 83.l7

22 % Yield on Purity 20.85 50.58 63.98 67.84 77.87

* 15 g Acetic aCId used for pH 9.5 to 10.5

85

9. Preparation of temephos using at different pH. .

Sr. Raw Material & pH

No. Parameters 9.5 to 10.5* 11 to 11.5 11.5 to 12 12 to 14 12 to 14

1 TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (m1) 1014 1014 1014 1014 1014

4 Toluene (ml) 1200 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9 9

6 TEDA (gms) 2.25 2.25 2.25 2.25 2.25

7 Na2C03 (gms) 10.5 10.5 10.5 10.5 10.5

8 DMTCL(gms) 337 337 337 337 353


10 DMTCL Add. Temp.(°C) 40 40 40 40 40

11 2N. NaOH (ml) 200 180 190 210 230

12 2N. Add. Temp (0C) 40 40 40 40 40

13 2N. Add. Time & Cooking 12 10 8 6 6 Time (hrs.)

14 Cooking Temp. (0C) 40 40 40 40 40

15 %DMTCL 0.58 0.69 0.24 0.37 0.20

16 Vol. ofOrg. (ml) 1180 1275 1325 1352 1365

17 WI. ofOrg. (gms) 1142 1230 1292 1308 1330


19 WI. of Product (gms) 120 265 330 342 391

20 % P of Temephos 83.58 89.20 91.23 92.78 93.65

21 % Yield on TDP 25.72 56.80 70.74 73.31 83.82

22 % Yield on Purity 21.50 50.67 64.54 68.02 78.49

* 15 g Acetic aCid used for pH 9.5 to 10.5

86

Cost Calculation:

TOP + 2NaOH + 20MTCL ---t Temephos + 2NaCI + 2H20 (Imp)

218.5 + 2 x 40 + 2 x 160.5 ---t 466.5

Theoretical : 220 + 80 + 321 Input/output

Actual Input/output

220 + 114.41 + 353

---t 466.5

---t 391 g.

+ 2 x 58.5 + 2 x 18

+ 117 + 37.5

+ 296.41


Remarks TOP 220 220/220 x 466.5 Temephos 391 391/466.5 x 100

93.65 (%p) = 83.82 C.S. lye. : 243.44 Temephos 366.17 366.17/466.5 x 100 (47 %) Imp_urity_ 24.83 = 78.49 Water 2414 Toluene reco. 915.90



TEO A 2.25 MeOH recov. 405 g

Na2C03 : 10.5 MeOH loss 72

OMTCL: 353

MeOH 477

Total : 4761.19 Total : 4761.19

87

Cost Calculation:

TDP + 2NaOH + 2DMTCL ---+ Temephos + 2NaCI + 2H20 (Imp)

218.5 + 2 x 40 . + 2 x 160.5 ---+ 466.5 + 2 x 58.5 + 2 x 18

Theoretical : 562.66 + 204.00 + 820.97 ---+ 1193.10 + ·394.53 Input/output

Actual : 562.66 + 292.60 + 902.81 ---+ 1000 g. + 758.07 Input/output


Remarks TDP 562.66 599.46/220 x 466.5 Temephos 1000 1000/1193.10 x 100

= 1271.12 93.65S%p) = 83.82 C.S.Lye: 622.61 Temephos 936.5 936.5/1193.10 x 100 (47 %) Impurity 63.5 = 78.49 Water 6174.00 Toluene reeo. : 2342.46 Toluene: 2640.00 Toluene loss : 297.54 TEBA 23.00 Aq to efflux. : 7317.68 TEDA 5.75 MeOH recov.: 1035.80 Na2COJ : 26.85 MeOH loss 184.20 DMTCL: 902.81 MeOH : 1220.00 Total : 12177.61 Total : 12177.61


TDP 403.00 0.5627 226.77

C.S. lye 14.00 0.6226 8.72

Toluene 31.00 0.2975 9.22

TEBA 120.33 0.023 2.77

TED A 863.54 0.00575 4.96

Na2C03 14.00 0.0268 0.38

DMTCL 160.00 0.9028 144.48

Methanol 16.93 0.184 3.12

TOTAL 400,42

88

10. Preparation of temephos using different temperature.

Sr. Raw Material & Temperature

No. Parameters 10° C 25° C 30° C 40° C 50° C

1 TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (ml) 1014 1014 1014 1014 1014

4 Xylene (ml) 1200 1200 1200 1200 1200

5 TEBA (gI?s) 9 9 9 9 9

6 TEDA (gms) 2.25 2.25 2.25 2.25 2.25

7 Na2C03 (gms) 10.5 10.5 10.5 10.5 10.5

8 DMTCL(gms) 353 353 353 353 353


10 DMTCL Add. Temp.(°C) 10 25 30 40 50

11 2N. NaOH (ml) 220 220 220 220 220

12 2N. Add. Temp (0C) 10 25 30 40 50

13 2N. Add. Time & 16 12 8 6 6 Cooking Time (hrs.)

14 Cooking Temp. (0C) 10 25 30 40 50

15 %DMTCL 1.01 1.64 0.44 0.33 0.38

16 Vol. of Org. (ml) 1273 1270 1315 1363 1338

17 Wt. ofOrg. (gms) 1236 1233 1290 1320 1305

18 Xylene recovered (ml) 1050 1055 1060 1060 1060

19 Wt. of Product (gms) 290 280 330 395 363

20 % P of Temephos 91.25 92.42 92.48 92.40 91.23

21 % Yield on TDP 62.17 60.02 70.74 84.67 71.80

22 % Yield on Purity 56.73 55.47 65.42 78.23 71.45

89

11. Preparation of temephos using different temperature.

Sr. Raw Material & Temperature

No. Parameters 10° C 25° C 30° C 40° C 50° C

I TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (ml) 1014 1014 1014 1014 1014

4 Toluene (ml) 1200 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9 9

6 TEDA (gms) 2.25 2.25 2.25 2.25 2.25

7 NaZC03 (gms) 10.5 10.5 10.5 10.5 10.5

8 DMTCL(gms) 353 353 353 353 353


10 DMTCL Add. Temp.(°C) 10 25 30 40 50

I I 2N. NaOH (ml) 220 220 220 220 220

12 2N. Add. Temp ("C) 10 25 30 40 50

13 2N. Add. Time & Cooking 16 12 8 6 6 Time (hrs.) .

14 Cooking Temp. (DC) 10 25 30 40 50

15 %DMTCL 1.08 1.6 I 0.46 0.37 0.30

16 Vol. ofOrg. (ml) 1270 1273 J3 15 1365 1340

17 Wt. ofOrg. (gms) 1232 1235 1288 1324 1309


19 Wt. of Product (gms) 288 282 330 397 364

20 % P ofTemephos . 91.23 92.41 92.46 93.12 91.56

21 % Yield on TDP 61.73 60.45 70.74 85.10 78.03

22 % Yield on Purity 56.32 55.86 65.40 79.24 71.44

90

12. Preparation of temephos using different DMTCL mole ratio:

Sr. Raw Material & TDP-DMTCL

No. Parameters 1 :2.5 1 :2.4 1:2.3 1:2.2 1:3

1 TDP (gms) 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170

3 Water (ml) 1017 1017 1017 1017 1017

4 Toluene (ml) 1200 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9 9

6 TEDA (gms) 2.25 2.25 2.25 2.25 2.25

7 NazCO) (gm's) 10.5 10.5 10.5 10.5 10.5

8 DMTCL(gms) 401.85 385 369 361 481.5


10 DMTCL Add. Temp.(°C) 40 40 40 40 40

I I 2N. NaOH (ml) 220 220 220 220 220

12 2N. Add. Temp (0C) 40 40 40 40 40

13 2N. Add. Time (hrs.) 2 2 2 2 2


15 Cooking Temp. (0C) 40 40 40 40 40

16 %DMTCL 3.80 3.01 2.58 1.84 5.62

17 Vol. ofOrg. (ml) 1375 1360 1340 1325 1390

18 WI. of Org. (gms) 1328 1320 1290 1275 1345


20 WI. of Product (gms) 415 405 380 365 428

21 % P ofTemephos 89.25 90.20 92.82 89.06 88.65

22 % Yield on TDP 88.96 86.82 81.46 78.24 91.74

23 % Yield on Purity 79.40 78.31 73.98 69.68 81.33

91

13. Preparation of temephos using different catalyst.

Sr. Raw Material & Catalyst

TBAB TBAB BA TEBA TEDA TEBAI No. Parameters

Chlorid{ TEDA I TDP (gms) 220 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170 170

3 Water (ml) 1017 1017 1017 1017 1017 1017

4 Xylene (ml) 1200 1200 1200 1200 1200 1200

5 TEBA (gmS) - - - 9 - 9

6 Catalyst (gms) 10 15 15 - - -7 TEDA (gms) - - - - 2.25 2.25

8 Na2C03 (gms) 10.5 10.5 10.5 10.5 10.5 20.5

9 DMTCL (gms) 353 353 353 353 353 353

10 DMTCL Add. Time (hrs.) 4 4 4 4 4 4

II DMTCL Add. Temp.(°C) 40 40 40 40 40 40

12 2N. NaOH (ml) 220 220 220 220 220 220

13 2N. Add. Temp (0C) 40 40 40 40 40 40

14 2N. Add. Time (hrs.) 2 2 2 2 2 2

15 Cooking Time (hrs.) 4 4 4 4 4 4

16 Cooking Temp. (0C) 40 40 40 40 40 40

17 %DMTCL 1.74 1.09 0.04 1.02 1.82 0.22

18 Vol. of Org. (ml) 1230 1290 1320 1310 1320 1380

19 Wt. ofOrg. (gms) 1201 1248 1294 1287 1291 1332

20 Xylene recovered (ml) 1060 1060 1065 1050 1055 1060

21 Wt. of Product (gms) 370 338 344 355 352 398

22 % P of Temephos 73.86 84.14 50.67 91.23 91.02 93.00

23 % Yield on TDP 79.31 72.45 73.74 76.09 75.40 85.32

24 % Yield on Purity 58.58 60.96 37.36 69.43 68.67 79.34

92

14. Preparation of temephos using different catalyst.

Sr. Raw Material & Catalyst

TBAB TBAB BA TEBA TEDA TEBAI No. Parameters

~hlorid! TED A I TOP (gms) 220 220 220 220 220 220

2 C.S. LYE (gms) 170 170 170 170 170 170

3 Water (ml) 1017 . 1017 1017 1017 1017 1017

4 Toluene (ml) 1200 1200 1200 1200 1200 1200

5 TEBA (gms) - - - 9 - 9

6 Catalyst (gms) 10 15 15 - - -7 TEOA (gms) - - - - 2.25 2.25

8 Na2C03 (gms) 10.5 10.5 10.5 10.5 10.5 20.5

9 OMTCL (gms) 353 353 353 353 353 353

10 OMTCL Add. Time (hrs.) 4 4 4 4 4 4

11 OMTCL Add. Temp.(°C) 40 40 40 40 40 40

12 2N. NaOH (ml) 220 220 220 220 220 220

13 2N. Add. Temp (OC) 40 40 40 40 40 40

14 2N. Add. Time (hrs.) 2 2 2 2 2 2

15 Cooking Time (hrs.) 4 4 4 4 4 4

16 Cooking Temp. (0C) 40 40 40 40 40 40

17 %OMTCL 1.22 0.14 0.09 1.01 1.72 0.12

18 Vol. of Org. (ml) 1225 1310 1315 1320 1330 1380

19 Wt. ofOrg. (gms) 1199 1288 1290 1291 1296 1331

20 Toluene recovered (ml) 1060 1060 1065 1060 1060 1060

21 wt. of Product (gms) 368 340 347 356 353 397

22 % P of Temephos 74.01 84.14 52.01 90.83 91.00 93.01

23 % Yield on TOP 78.89 72.89 74.38 76.31 75.67 85.10

24 % Yield on Purity 58.38 61.32 38.69 69.32 68.86 79.15

93

15. Miscellaneous

DDS: NazCO)

Sr. No. Raw Material & Addition tern erature 20° C

Parameters 1:1.42 1:1 1:0.85 1 :0.5

I TOP (gms) 220 220 220 220

2 C.S. LYE (gms) 160 160 160 160

3 Water (ml) 1014 1014 1014 1014

4 Toluene (ml) 1200 1200 1200 1200

5 TEBA (gms) 9 9 9 9

6 TEOA (&ms) 2.25 2.25 2.25 2.25

7 Na2C03 (gms) 150 106 90 53

8 OMTCL(gms) 353 353 353 353

9 OMTCL Add. Time (hrs.) 4 4 4 4

10 OMTCL Add. Temp.(oC) 20 20 20 20

II 2N. NaOH (ml) 220 220 220 220

12 2N. Add. Temp (oc) 35-40 35-40 35-40 35-40

13 2N. Add. Time (hrs.) 2 2 2 2


15 Cooking Temp. (0C) 40 40 40 40

16 %OMTCL 0.32 0.21 0.18 0.20

17 Vol. of Org. (ml) 1365 1370 1375 1370

18 Wt. ofOrg. (gms) 1325 1330 1335 1320

19 Toluene recovered (ml) 1050 1060 1060 1035

20 Wt. of Product (gms) 405 408 411 398

21 % P of Temephos 88.32 90.86 93.28 92.56

22 % Yield on TOP 86.81 87.45 88.10 85.31

23 % Yield on Purity 76.67 79.46 82.18 78.76

94

Stability Data

Solvent Initial Stability at Stability at Stability at Stability at % Purity 90° C 10 hrs. 90° C 24 hrs. 55° C 7 days 55° C 14 days

%P %P %P %P MDC 92.24 72.87 70.67 82.62 76.56

MDC 92.22 71.82 70.12 81.63 74.67

Benzene 91.75 89.23 ·88.33 89.67 89.23

Benzene 85.00 84.37 83.23 84.47 83.69

Xylene 91.88 91.81 90.58 90.53 90.21

Xylene 92.46 91.67 91.04 91.23 90.28

Toulene 91.92 91.88 91.23 91.37 90.80

Toulene 93.28 92.88 92.38 92.92 92.70

95

Cost Calculation:

TDP + 2NaOH + 2DMTCL -> Temephose + 2NaCI + 2H20 (Imp)

218.5 + 2x40 + 2x 160.5 -> 466.5 + 2 x 58.5 + 2 x 18

Theoretical : 220 + 80 + 321 -> 466.5 + 117 + 37.5 Input/output

Actual Input/output

:220+ 110 + 353 . -> 411 g. +272

Input Theoretical Actual outputs Yield on Theoretical in gms. outputs in gms. in gms. Remarks

TDP 220 220/220 x 466.5 Temephose 411 411 1466.5 x 100 93.28 (%p) = 88.10

C.S. lye. : 233.44 Temephose 383.38 383.38/466.5 x 100 (47 %) I~uritl' 27.61 = 82.18 Water 2214 Toluene reeo. 911.6



TEDA 2.25 MeOH recov. 405 g

Na2COJ ; 90 MeOH loss 72

DMTCL: 353

MeOH 477

Total : 4800.25 Total :

4800.25

96

Cost Calculation: .

TDP + 2NaOH + 2DMTCL ~ Ternephose + 2NaCl + 2H20 (Imp)

218.5 + 2 x 40 + 2 x 160.5 ~ 466.5 + 2 x 58.5 + 2 x 18

Theoretical : 535.27 + 194.64 + 781 Input/output

~ 1135 + 375.91

Actual I t/

: 535.37 + 267.63 + 858.86 ~ 1000 g. + 661.76 nIlu oUl~U


Remarks TDP 535.27 535.27/220 x 466.5 Temephose 1000 1000/1135 x 100

= 1135 93.28 (%p) = 88.10 C.S. Lye: 569.45 Temephose 932.8 932.8/1135 x 100 (47 %) Impurity 67.2. = 82. I 8 Water 5386.86 Toluene reco. ; 2218.00 Tolucne : 2510.94 Toluene loss 292.87 TEBA 21.89 Aq to efflux. : 6596.80 TED A 5.47 MeOH recov. 984.91 Na2CO] 218.98 MeOH loss : 175.09 DMTCL: 858.88 MeOH : 1160.58 Total : 11268.32 Total : 11268.32


TOP 403.00 0.5352 215.69

C.S. lye 14.00 0.5694 7.97

Toluene 31.00 0.2929 9.08

TEBA 120.33 0.0219 2.64

TEOA 863.54 0.0054 4.66

Na2C03 14.00 0.2189 3.06

OMTCL 160.00 0.8589 137.42

Methanol 16.93 0.1750 2.96

TOTAL 383.48

97

SECTION - II

MALATHION

2.1 REVIEW

Malathion conformed to the general formula138:

S R10 II

;P-S-CHCOOR3 R20 I

CH2COOR4

where R, and R2 are chosen· from the group consisting of aliphatic and aromatic

hydrocarbon radicals, and R3 and ~ are chosen form the group consisting of hydrogen,

aliphatic and aromatic hydrocarbon radicals.

In the new compounds the R,s may be the same or different radicals, and when

they stand for aliphatic radicals it is to be understood that they represent both the straight

chain and branch chain, the saturated and unsaturated, and the cyc10aliphatic hydrocarbon

radicals. Typical examples of these radicals are methyl, ethyl, n-propyl, isopropyl, n-butyl,

isobutyl, sec.-amyl, n-hxyl, 2. ethyl-hexyl, n-octyl, n-decyl, n-do-decyl, leyl, catyl, ceryl,

ceryl, allyl, cyclohexyl, phenyl and naphthyl.

0, O-Dialkyl dithiophophosphoric acid has the formula,

in which R, and R2 have the meaning shown above, with an unsaturated compound of the

formula,

CHCOOR3 II CHCOOR4

in which R3 and ~ have the meaning shown above.

98

A typical reaction in which O,O-dimethyl dithiophosphoric acid is reacted with

diethyl maleate to produce S- (l,2-dicarbethoxyethyl) O,O-dimethyl dithiophosphate

(Malathion) may be illustrated as follows:

S

CH30--......11 --~ /P-S-CHCOOC2Hs

CH30 I CH2COOC2Hs

The unsaturated compounds utilized in the present process may be either maleic

acid, the acid maleate esters, the neutral maleate esters, or their isomers, fumaric acid, the

acid fumarate esters and the neutral fumarate esters. Therefore, it is to be understood that

the formula

CHCOOR3 II CHCOOR4

used in this specification and the appended claims is intended to represent both the maleate

and fumarate compounds.

When one or both of the reactants are solids, the reaction is preferably carried out

in the presence of a solvent. Such solvents include the low molecular weight aliphatic

monobydric alcohols, the ketones such as, for example, methyl ethyl ketone,

acetophenone, and the like; aliphatic esters such as ethyl acetate, benzene, xylene,

chloroform carbon tetrachloride and toluene.

The reaction is preferably carried out at a temperature within the range of 200 to

1500 C. However, temperatures outside of this range may be employed depending upon the

type of reactants and solvents utilized.

The reaction may be accelerated by using an aliphatic teritary amine catalyst, such

as for example triethylamine, triisopropylamine, tri-n-butylamine, tri-2-ethylhexylamine,

and the like. The amount of catalyst employed is usually within the range of from 0.2% to

2.0%, based on the total weight of the reactants.

99

An anti-polymerization agent such as hydroquinone may be employed to guard

polymerization of the maleate or fumarate compound.

Continued, sustained effort has been expended to further improve its odor, color

and stability, as evidenced, for instance, by U.S. Patents 2,879, 284, 2,962, 521 and

2,980,723. In this connection, it has been determined that malathion, as produced by prior

art processes, contains a small amount of die thy I fumarate, usually between about I to 4 %

by weight of the technical grade material. Unfortunately, diethyl furmate has been found to

cause skin sensitization or irritation to some people. To alleviate or reduce any likelihood

towards skin sensitization, it is therefore, desirable to provide an improved malathion

containing minimal amounts of diethyl fumarate or diethyl maleate. If such a process could

be provided, particularly one which simultaneously increases production yield while

decreasing the amount of diethyl maleate in technical grade malathion, such a process

would fill a long-felt need in the art. 139

In accordance with the process described here, the aforementioned objectives are

achieved in an economical and straight forward manner. There is initially reacted

phosphorus pentasulfide and methonol in the presence of a suitable solvent, such as

dioxane, benzene or toluene, at an elevated temperature, typically between about 170° and

190° F. and preferably between 175° and 185° F. to prepare 0, 0-

dimethyldithiophosphoric acid. The reaction mixture comprises approximately from 60 to

65 % of 0, O-dimethyldithiophosphoric acid. The mixture is next reacted with diethyl

maleate, usually in a mole ratio of from about 1.02 to 1.15, and preferably from 1.02 to

1.10 mols ofO, O-diethyldithiophosphoric acid to 1.0 mol of diethyl maleate.

The reaction is terminated when the desired reaction product, namely, crude

malathion, contains approximately between 10 to 25% of unconverted reactants. This

terminal point is readily determined by intermittently analyzing the condensation of

reaction mixture. Condensation reaction temperature is maintained from about 175° to

225° F., and preferably between 190° and 200°F. During the initial reaction period,

pressure is reduced from 760mm. Hg to between 20 and 30 mm. Hg. The residence time

100

for effecting partial or incomplete reaction is approximately three hours, during which time

essentially all of the solvent is stripped off and recovered.

Malathion containing less than 0.5% of diethyl fumarate can, if desired, be readily

prepared from the above recovered steam-stripped product. The latter may be treated with

an aqueous solution containing sodium sulfide, sodium sulfite, potassium sulfide,

potassium sulfite, ammonium sulfide or ammonium sulfite to establish a pH of at least 7,

and preferably between 7.1 and 7.5. The organic phase containing malathion of less than

0.1 % diethyl fumarate content is then separated from aqueous layer.

A process developed by M. Usui;14o U. S. Patent 2,962,521; November 29,1960;

assigned to Sumitomo Chemical Company Ltd., Japan relates to an improved method for

decolorizing and deodorizing dithiophosphate pesticides and for stabilizing such pesticides

against formation therein of objectionable color and odor bodies.

Dithiophosphate pesticides of the type with which this process is concerned may be

represented by the formula in which RI, R2, R3 and ~ are each an aliphatic or aromatic

S R10,,11

P-S-CHCOOR3 / I

R20 CH2COOR4

hydrocarbon radical. Such esters are well known and may be conveniently

prepared, for instance, by reacting on 0, O-dialkyl dithiophosphate with a dialkyl maleate

as as described in U. S. Patent 2,578,652. A typical and well known ester of this class is 0,

O-dimethyl-S-(l,2-dicarbethoxyethyl) - dithiophosphate which is commercially available

as malathion. It is with this latter compound that this process is particularly concerned and

to which the following description is directed. Nevertheless, it is to be understood that this

process of decolorization, deodorization and stabilization is equally as applicable to other

dithiophosphate esters of the above class.

Technical grade dithiophosphate pesticides as manufactured are yellow-brown to

brown in color and give off a peculiarly offensive odor. Usually the purity of such

101

I .-j. technical grade dithiophosphates is about 94%. When employed as insecticides for

agricultural purposes, the color and odor of such compounds, while not desirable, do not

unduly restrict their use. The color and odor of these compounds are sufficiently

obnoxious, however, to seriously hamper the use of these pesticides for public health

purposes especially in or near households. Although various proposed methods of

purification have offered some measure of improvement, none has proved wholly

successful in providing a stabilized, substantially color and odor free pesticide. There has

continued to remain, therefore, a need for a means for removing color and odor from

technical grade dithiophosphate pesticides and for stabilizing such pesticides against

further formation therein of objectionable color and odor bodies.

It is a primary object of this process to fulfill this need. It is a further object to

decolorize and deodorize technical grade dithiophosphate pesticides and to so stabilize

them. It is a still further object to provide color and odor free dithiophosphate pesticides

particularly adapted for use in or near households and public buildings for public health

purposes. These objects have been met to a surprising degree by a process which is simple

and economical. In general, this process comprises providing in an emulsion of a

dithiophosphate ester and an aqueous alkali metal hydroxide or carbonate, a small amount

of a peroxide or hydroperoxide. After agitation for a period of. time, the mixture is

permitted to stratify. The oil layer is separated, washed and dried to give a color-and odor

free dithiophosphate ester.

It is an advantage that the process may be practiced either on a technical grade

dithiophosphate pesticides or during the manufacture thereof. In the latter case, an aqueous

alkali metal carbonate or hydroxide is added, for example, to the reaction mixture of an 0,

O-dialkyl dithiophosphoric acid and a dialkyl maleate and the mixture agitated to form an

emulsion. To this is added, with agitation, a peroxide or hydroperoxide. After thorough

distribution, the mixture is stratified and the oil layer separated, washed and dried.

The aqueous alkali metal carbonate or hydroxide in which the dithiophosphate is

emulsified will usually be soda ash or caustic soda, although this may be otherwise varied

102

as desired. The concentration of such an aqueous solution may vary considerably but

generally will not be greater than about 10%. Usually from about a 2 to 10% aqueous

solution will be employed. The amount of solution employed likewise will vary but will

usually be at least about twice the weight of the dithiophosphate ester.

The amount of peroxide or hydroperoxide may also be varied. It has been found

that as little as 0.01% based on the weight of the dithiophosphate, when added to the

emulsion, will result in a considerably improved product. Greater amounts may be

employed with more effectiveness but little if any added advantage appears to be gained by

employing more than about 1.5%. The usual practice will be to use from 0.1 to 1.0% of

peroxide based on the weight of the dithiophosphate ester. Various peroxides and

hydroperoxides, both organic and inorganic, may be used. Illustrative of these are

hydrogen peroxide, benzoyl peroxide, dibenzoyl peroxide, potassium peroxide, calcium

peroxide, di-t-butyl peroxide, cumene hydroperoxide, pinene hydroperoxide, t-butyl

hydroperoxide, and the like.

The activity of P2SS was detected by the evolution of H2S in reaction with EtOH.

Activity of different specimens of P2SS varied over a wide range. 141

The ester (MeO)2 P (S) SH, a reactant of the synthesis of the insecticide Rogor, was

prpd. in 75-80% yields by reaction of P2SS with MeOH under the optimal conditions of 50-

60°, 2-3 hr, P2SS : MeOH molar ratio 1:4 the reaction had activation energy 6.1

kcaIlmole. 142

Reaction of P2SS with 4.4 molar equi. MeOH in PhMe at 50-60° with an activity

energy of 6.1 KcaIlmole. 143

A mixture of2 moles Diethylmaleate, 4 moles MeOH and 0.5 mole P4S iO is heated

with mechanical agitation untill refluxing cases. The reaction yields a liquid (b3171 °

(decomp.) n20 1.4854,70% yield.

103

Condensation of 2 moles Maleic anhydride, 8 moles MeOH, and 0.5 mole P4SIO

appear to yield an even less toxic and more potent insecticide. 144

A mixture of 920 g. (MeO)2 peS) SH (I, 54.3 wt. %) in PhMe prepared from 444 g.

P4SIO, 300 g. MeOH, and 300 m!. PhMe was purified by the addition of 25.7 wt. % aq.

NaOH to pH 5.5 - 6 at 30° with vigorous sterring, the resulting - 53 wt. % 1 Na-aqueous

solution was treated with 248 g. PhMe, acidified with 371 g (99 wt. %) H2S04 at 35° C to

give 750 g. I-PhMe solution contg. 66-7 wt % pure 1 (78-80% yield) which was useful as

insecticide. 145

Title comps (RO)2 peS) SH (I, R = Me and iso-) were prepared by reaction of P2SS

at 120-40°, with MeOH in 1:2 molar ration 20°.146

(MeO)2 peS) SH was heated at 80° for 4 hrs with maleic anhydride and the

resulting ester heated at 80-5° for 6 hrs. with EtOH 736 parts and conc. H2S04 to give

90%. S- (I, 2-carboethoxylethyl) 0, O-dimethyl dithiophosphate.147

Treating MeOH with P4SIO suspended in an inert solvent, i.e. standard hydrocarbon

in which the title coinpound. (I) is sparingly soluble, makes it possible to separation 1 from

solvent and use the solvent in second run. A small amount of kerosene dissolved in the

acid layer serves as a collector of impurities. Thus, to a mixture of 200 m!. kerosine (163.5

g) and 147.5 g. P4S IO, 87.5 g, MeOH is added with stirring at 40-50°. The Mixture stirred I

hr. at 60-5°. cooled to 20°, and separated to give in the lower acid layer 188.1 g. 1 suitable

for manufacture of water-sol salts!48

The 0, O-dimethyldithiophosphoric acid was prepared best by dropwise addition of

technical MeOH at 3% excess I hr at 50°, to suspension of finely ground P2SS in kerosene

(15-18% fresh, remainder from preceding reaction), after I hr at 65° on cooling two layers

separated. The top (Kerosine) layer recycled and the bottom DMT A transferred for

transformation into sodium salt of DTA by treatment with concentrated NaOH to pH 5-6 at

20-30°, in the presence of I: 1.25 DMTA-H20 to give and top oily waster, and a bottom

aqueous solution of sodium salt ofDTA contain 28-9% DMTA, at 75-80% yield!49

104

I -j The reaction between anhyd. MeOH and P2SS to gIve (MeO)2 PS2H (I) was

improved. The addition of the by-products from one reaction hindered the formation of by

products and increased the yield of (I). Anhyd, MeOH (315 m!.) was added to 400g. P2SS

and 200g. of an anhydrous oily fraction of by-products obtained froin the reaction between

(MeOh P02H, P2SS and anhydrous MeOH gave 244 g of an oily fraction and an aqueous

solution of (MeOh PS2Na. The yield of (I) was 83% when preformed (I) was added with

P2SS as a disperting agent, the yield of (I) was not higher than 64.4%.150

To 24 g. MeOH was gradually added 33.3 g. P4SjQ, and the mixture warmed on a

steam bath until H2S evolution ceased, filtered and distilled, yielding 73% (MeO)2 PS2H,

b4s 62-3° n20D 1.5343, d20 1.2888, S20 38.87.151

A most of 40 m!. anhydrous benzene and 35.2 g. P2SS, treated dropwise at 400 with

28.8 m!. anhydrous MeOH stirred 3 hrs, and freed of solvent under reduced pressure, gave

35g. 0, O-dimethyl hydrogen phsophrodithioate.152

Malathion (I) (100 g) purity 94.4% and free acid content 0.33% was agitated

vigorously in 200 m!. 20% Na2C03. This mixture was treated dropwise with 28 m!. 3%

H20 2 and the oily layer washed with H20 to give 93.5 g, I, n2D 1.4983, purity 96% and

free acid content 0.14%.153

(ROh PS2H (R = Me, Et) prepared by treating P2SS with ROH in PhMe, were

purified to 98% purity by extraction of mixture with H20 and extraction of the aqueous

phase with PhMe in the presence of NaCI, or by neutrilization of the crude mixture with

aqueous NaOH to pH 3 and extraction with H20. Thus, 204 g. MeOH was added at 800 in

that to 333 g P2SS in Ph Me and the mixture was stirred that at 90°. A (500 m!.) was

extraction with 500, 400 and 2 x 300 m!. H20, and the combined aqueous phase was

extraction with 250, 200, and 100 m!. PhMe in the presence of 400,50, and 25 g NaCI

respective to give 700 m!. PhMe solution containing 210-45 g (MeOh PS2H of 99.5 -

99.8% purity.154

105

A continuous process was developed (app. diagram given) for preparation of (ROh

P (S) SH by treating a sludge of P4SIO and product with in aliphatic alcohol and drawing

off the product with a specially designed tube. Thus, 1.3 ml/min. MeOH and 1.7 glmin.

P4SIO were added to a sludge of 417 ml. P4SIO and 833 ml. (MeOh P (S) SH was

withdrawn and chlorimated at 60° to give (MeOh peS) CI. 155

Title substances were isolated from the reaction mixture of P2Ss and MeOH or

EtOH in PhMe. To increase the. degree of isolation, the reaction mixture was extraction,

periodically or continuously with H20 (200-350) parts by wt.!100 part by wt. reaction

mixture) with subsequent treatment of the aqueous phase with Ph Me (20-60 part by

wt.!IOO part by wt. aqueous phase) concentrated NaCI (I 5-30 part by wt.!IOO part by wt.

aqueous phase ).'56

(MeO)2 P (S) SCH (C02 Et) CH2C02Et (malathion. I) is prepared by addition of

(MeO)2 peS) SH' (II) to maleic anhydride (III) in the presence of Et3N or

triethylenediamine (0.05-0.1 % vs. anhydride) at 20-30° over 3-4 h, followed by

esterification with EtOH in C6H6. PhMe. EtCOMe, or ClCH: C Ch. Thus, a mixture of 150

g 96% III, 275 g 80 % III in PhMe, and 5 mL20% Et3N in PhMe was stirred for 5 hat 20-

30° and heated for 30 min. at 40-50°. The mixture 3 was treated with 98% EtOH 260,

PhMe 300, and 98% H2S04 4 g., heated for 4 h at 60-70°, azeotropically distilled to

remove H20, washed and distilled to give 565 g product concentrate 80%.157

2.2 MALATHION PHYSICAL DATA

S

II (CH30)2 -P-S-CH-CH2-COO-CHr CH3

I COO-CH2-CH3

106

NOMENCLATURE

Common Name:- Malathion (BS!, E-ISO, m-F-ISO, ESA BAN) maldison (Australia,

Newzeland), Malathion (JMAF) mercaptothion (South Africa) Carbofor (USSR)

noname (Germany), mercaptotion (Argentina)

IUPAC name: Diethyl (dimethoxythiophosphoryl thio) succinate; S-I,2-bis(9-

ethoxycarboryl)-ethyl O,O-dimethyl phosphorodithioate.

C.A. Name: diethyl[(dimethoxy phosphinothioyl) thio] butanedioate.

CAS RN (121-75-5) Development code EI 4049 cyanamid official code OMS 1; ENT

17034.

Physico-Chemical Properties .

Composition:- Tech grede in C-95% pure.

Mol. Weight-330.3

Mol. Formula:- CIOHI906PS2

Form:- Tech. grade is a clear amber liquid.

M.P.:- 2.85° C

Boiling Point:- 156_157° CIO.7mm/Hg.

Vapour Pressure:- 5.3 mpa

SG/density:- 1.23 (25°C)

Kow 560

Solubility: Solubility in water 145 mg/l lit (25°C). Miscible with most organic solvents,

e.g. alcohols, esters, ketones, ethers, aromatic hydrocarbons. Slightly soluble in

petroleum ether and some types of mineral oil. Stability: relatively stable in neutral

aqueous media. Decomposed by acids and alkalis.

COMMERCIALISATION:

History: Insecticide reported by G.A. Johnson et al. C. J. Econ, Entomal, 1952, 45,

279) Introduced by American Cyanamid Co. rights later transferred to Cheminova

Patents US 2578652.

107

Manufacturer: All India Medical, Cheminova, Excel, Hindustan Insecticides, Mis

Pesticides India.

APPLICATIONS

Mode of action: Non-systemiC insecticide and acaricide with .contact, stomach and

respiratory action, cholinesterase inhibitor.

Uses: A non systemic insecticide and acaricide of low mammalian toxicity, used to

control Coleoptera, Diptera, Hemiptera, Hymenoptera and Lapidoptera in a wide range

of crops including cotton pome, soft and stone fruit, potatoes, rice, vegetables, used

extensively to control major arthropod disease vectors (Culicidae) in public health

programmes, ecto parasites (Diptera, Acari, mallophaga) of cattle, poultry dogs and cats,

human head and body lice (Anoplura), household insects (diptera, orthoptera) and for

the protection of stored grain phytotoxicity. Non phytotoxic in general, if used as

recommended but glasshouse cucurbits and beans, certain ornamentals and some

varieties of apple, pear and grape may be injured.

FORMULATION TYPE: EC: WP: DP: UL

Compatibility

Compatible with most insecticides and fungicides; but incompatible with alkaline

materials (residual toxicity may be decreased).

Principal trade name:- 'Celthion' (Excel), 'Fyfanon' (Cheminova), 'Malatox' (Mis

Pesticide India Siapa), 'Malixol' (Rhone-poulene), 'MLT' (Symitomo), Mixtures

[Malathion+ 1 fenitrothion; parathion; parathion-methyl; dichlorvos; methoxy chlor+

parathion; piperonyl butoxide + pyrethrins.

ANALYSIS

Product analysis by G.K CCIPAC Handbook, 1983, IE 1952 AQAC methods 1990

(979.05) Residue determined by glc.

108

,~

MAMMALIAN TOXICOLOGY

Reviews: Pesticide residue in food FAO Agricultural studies No. 73 WHO Technical

Report Series No. 370, 1967 Evaluation of some pesticides residues in food FAO/PL

CP/15 WHO/food add. 67.321967 IARC 30.

Acute oral: LDso for rats 1375-2800 mice 775-3320 mg/kg

Skin and eye: Actue percutaneous LDso(244) for rabbits 4100 mg/kg.

NOEL: In 21 month feeding trails, rats receiving 100 mg/kg diet showed normal weight

gam.

ADI(JMPR): 0.02 mg/kg b.w. [1966]

Toxicity class: WHO III; EPA-III ECOTOXICOLOGY

Birds: Five day dietary LCso for bobwhite quail 3500, ringneck, pheasants 4320 mg/kg

diet. Fish: LCso (96h) for bluegill sunfish 0.1 largemouth bass 0.28 mg/I. Bees: Toxic

to bees LDso (topical) 0.71 Ilg/bee

ENVIRONMENTAL FATE

Animals: In mammals, following oral administration the major part of the dose is

excreted in the urine and faeces within 24 hours. Degradation is by oxidative

desulfuration by liver microsomal enzymes, leading to the formulation of malaoxon;

malathion and malaoxon are hydrolysed and thus detoxified by carboxylesterases. In

insects, metabolism involves hydrolysis of the carboxylate and phosphorodithioate

esters, and oxidation to malaoxon.

109

2.3 COMMON PROCESS

SPECIFICATION

Stage 1 :

Phosphorous penta sulfide

Stage 2 :

Methanol

AND RAW MATERIAL

S CH30"",,-11

P-SH CH30/

+

0, O-dimethyl dithiophosphoric acid (OMTA)

S

CH 30"",,-11 __ /p-S-CHCOOC2H5

CH30 I CH2COOC2H5

OMTA OEM Malathion O,O-dimethyl Oiethyl maleate dithiophosphoric acid

In a four necked flask (1 lit.) are placed phosphorus pentasulphide (P2Ss, 222.0

gm., 1m), and solvent toluene (87 mI.). The flask is fitted with a condenser, thermometer

pocket and an addition funnel. Starring is standard and temperature is raised to 70-75° C

methanol (128 gm., 4 m) is added over a period of 4 hours. The addition temperature is

maintained between 70-75° C. After the addition the reaction mixture is maintained at 75°

C for half an hour under stirring conditions. H2S evolved during the reaction is scrubbed

through H2S scrubbers arranged in series to manufacture NaHS.

The reaction mixture is at cooled to 25° C and filtered to remove any solid present.

The solution of dimethyl thiophosphoric acid in toluene is subjected to further reaction

after routine checking for acidity and purity.

110

The acidity is checked by titration method and purity is checked by GC profile.

Preparation of Malathion diethyl [( dimethoxy phosphinothioyl)thio 1 butanedioate.

In a four necked round bottom flask (1 lit.) fitted with a reflux condenser

thermometer pocket, a stirrer and addition fUlillel are placed diethyl maleate (190 gm, 1.1 0

mole) and the catalyst (hydroquionone, Igm). The stirrer is started 'and temperature raised

to 65° C. DMTA solution in toluene is slowly added during four hours maintaining

temperature between 63 - 67° C. After completion of addition the reaction mixture

temperature is raised to 72-74° C and maintained for 16 hours with stirring (cooking).

The reaction mixture is successively washed with water (500 ml), twice with

aqueous NaOH (5 %, 250 ml), aqueous NazSO] (6 %, 250 ml) and water. The solvent is

distilled off. It is further kept at 100° C for two hours under vacuum to remove toluene and

moisture to get nearly colourless liquid product.

The product is checked for moisture content (by Karl-Fisher), specific gravity and

purity (by GC internal standard method).

In our attempt to optimise reaction conditions we have performed several

experiments under different reaction conditions. During the preparlj.tion of DMT A, I have

changed mole ratio, solvent, water content, temperature and catalyst to get the best results.

In second stage again we have used different temperature, mole ratio and catalyst

proportion. Moreover, we have attempted a new procedure wherein 95% pure Malathion

(Heal) is added at the beginning of the second stage to study effect of the presence of

Malathion on the reaction. All these results are tabulated in Table. I to 10.

RAW MATERIAL SPECIFICATION OF MALA TRION:

Appearance

Phosphorus content

Sulphur content

Sieve test

Yellowish green to grayish free flowing powder

27.8 - 28.4 %

71.6 -72.2 %

65 - 75 % passed through 60 mesh in sieve test.

III

I -.,

M.P.

B.P.

MeOH

Appearance

Assay

B.P.

Sp. Gr.

Appearance

Assay

Sp. Gr.

Appearance

Assay

Sp. Gr.

HQ

Appearance

Assay

MALATHION

2880 C

510 to 525 0 C


99%

65 to 67 0 C.

0.784 - 0.800


98 - 99 %

1.062 - 1.068


99%

0.725

Photographic grade

Slight Yellow Color Powder

98 - 99 %

Malathion Content = 95 % min. w/w

Water Content = 0.1 % max. w/w

Material insoluble in acetone = 0.5 % w/w max.

Specific gravity 25 0 C between = 1.225 - 1.230

Malathion I kg. = 120 Rs.

112

2.4 EXPERIMENT DATA AND COST CALCULATION

1. SYNTHESIS OF DMTA USING DIFFERENT SOLVENT

Sr. Raw Material Detail P2S5 : Methanol No. Benzene Toluene

1:1.01 1:1.05 1: 1.01 1:1.05 I Weight ofP2Ss (gms) 222 222 222 222

2 Volume of Solvent (ml) 87 87 87 87

3 Weight of Solvent (gms) . 75 75 75 75

4 Volume of Methanol (ml) 164 170 164 170

5 Weight of Methanol (gms) 130.4 135 130.4 135

6 Addition Time (hrs.) 4 4 4 4

7 Addition Temperature (~C) 70-75 70-75 70-75 70-75

8 Cooking Time (hrs.) 112 112 1/2 112

9 Cooking Temperature (0C) 70-75 70-75 70-75 70-75

\0 Weight ofDMTA (gms) 288 317 384 389

II Volume ofDMTA (ml) 235 262 327 330

12 Sp. Or. ofDMTA 1.225 1.21 1.174 1.178

13 % Acidity ofDMTA 70.87 69.23 75.86 71.88

14 % Purity by O. C. 52.62 78.87 91.92 84.31

15 Unreacted P2SS (gms) 20 15 - -

16 WI. gain ofH2S scurrber (gms) 21 23 30 28

17 % Yield on acidity 64.58 69.44 91.86 88.48

18 % Yield on purity 37.88 62.50 88.24 81.99

113

2. SYNTHESIS OF DMT A USING DIFFERENT MOLE RATIO

Sr. Raw Material Detail P2SS : Methanol No. 1:0.96 1:0.98 1:1 1: 1.03

I Weight of P2SS (gms) 222 222 222 222

2 Volume of Toluene (m!) 87 87 87 87

3 Weight of Toluene (gms) 75 75 75 75

4 Volume of Methanol (m!) 155 159 162 167

5 Weight of Methanol (gms) 123.3 126.5 128.8 132.8


7 Addition Temperature (0C) 70-72 70-72 70-72 70-72

8 Cooking Time (hrs.) 112 112 112 112


10 Weight ofDMTA (gms) 375 376.5 383 387

I I Volume ofDMTA (ml) 315 318 325 330

12 Sp. Gr. ofDMTA 1.19 1.1 79 I. I 78 1.172

13 % Acidity ofDMTA 75.18 76.34 76.52 71.88

14 % Purity by G. C. 91.31 91.05 93.02 83.78

15 Unreacted P2SS (gms) 4 2 - -16 Wt. gain of H2S Scurrber(gms) 28 29 30.5 30

17 % Yield on acidity 89.21 91.31 92.74 88.03

18 % Yield on purity 85.60 86.04 89.06 81.05

114

, ---3. SYNTHESIS OF DMT A USING DIFFERENT WATER CONTENT

Sr. Raw Material Detail Water Content No. 4 ml 10 ml 20 ml 25 ml

I Weight ofP2Ss (gms) 222 222 222 222.

2 Volume of Toluene (ml) 87 87 87 87


4 Vol ume of Methanol + water (ml) 162 + 4 162 + 10 162 + 20 162 + 25

5 Weight of Methanol + water(gms) 132 138 148 153


7 Addition Temperature (ec) 70-75 70-75 70-75 70-75

8 Cooking Time (hrs.) 112 112 112 112

9 Cooking Temperature (ec) 70-75 70-75 70-75 70-75

10 Weight ofDMTA (gms) 388 350 ·317 388


12 Sp. Or. ofDMTA 1.21 1.20 1.348 1.34

13 % Acidity ofDMTA 74.21 73.01 67.01 67.00

14 % Purity by O. C. 85.28 82.87 53.56 39.89

15 Unreacted P2SS (gms) 2 6 25 27

16 WI. gain of H2S scurrber (gms) 28 26 21 18

17 % Yield on acidity 91.11 81.08 67.22 61.06

18 % Yield on purity 82.68 72.51 42.44 28.72

115

1--<1.

4. SYNTHESIS OF DMTA USING DIFFERENT TEMPERATURE

Sr. Raw Material Detail TEMPERATURE (0 C) No. 15 - 20 35 - 40 45- 50 65 - 70 I Weight ofP2Ss (gms) 222 222 222 222




5 Weight of Methanol (gms) 128 128 128 128


7 Addition Temperature (OC) 15-20 35-40 45-50 65-70

8 Cooking Time (hrs.) 112 112 1/2 112

9 Cooking Temperature (OC) 15-20 35-40 45-50 65-70

10 Weight ofDMTA (gms) 345 350 358 366


12 Sp. Or. ofDMTA 1.21 1.198 1.213 1.173

13 % Acidity ofDMTA 72.38 72.46 72.56 73.51

14 % Purity by O. C. 81.39 83.85 84.18 87.80

15 Unreacted P2SS (gms) 15 10 6 2

16 Wt. gain ofH2S scurrber(gms) 22 24 25 27

17 % Yield on acidity 79.02 80.25 82.20 85.14

18 % Yield on purity 70.19 73.36 75.34 80.34 .

116

5. THESIS OF DMTA USING DIFFERENT TEMPERATURE

Sr. Raw Material Detail TEMPERATURE (0 C) No. 70 - 72 72 - 76 78 - 80 82 - 85

1 Weight of P2SS (gms) 222 222 222 222






7 Addition Temperature (0C) 70-72 72-76 78-80 82-85

8 Cooking Time (hrs.) 112 112 112 112



11 Volume ofDMTA (ml) 329 330 327 325

12 Sp. Or. ofDMTA 1.173 1.175 1.171 1.169

13 % Acidity of DMT A 75.82 76.30 75.32 73.82

14 % Purity by G. C. 89.80 92.08 90.36 85.99

15 Unreacted P2SS (gms) - - - -16 Wt. gain ofH2S scurrber (gms) 31 31.5 29 27

17 % Yield on acidity 92.61 93.68 91.29 88.77

18 % Yield on purity 86.66 89.31 86.51 81.69

117

6. THESIS OF DMTA USING DIFFERENT CATALYST

Sr. Raw Material Detail Catalyst, No. 0.5 1.0 1.0 Without

Catalyst 1 Weight of P2SS (gms) 222 222 222 222





6 Weight ofTEA (gm) (Catalyst) 0.5 1.0 - -7 Weight of Lutidine (gm) (Catalyst) - - 1.0 -


9 Addition Temperature (DC) 72-76 72-76 72-76 72-76

10 Cooking Time (hrs.) 112 112 112 112

11 Cooking Temperature (DC) 72-76 72-76 72-76 72-76


13 Volume ofDMTA (ml) 326 315 305 333

14 Sp, Or. ofDMTA 1.18 1.171 1.186 1.174

15 % Acidity ofDMTA 73.46 72.04 70.46 76,18

16 % Purity by O. C. 86.30 82.80 75.53 92,26

17 Unreacted P2SS (gms) - 4 8 -

18 WI. gain ofH2S scurrber(gms) 29 27 24 31.5

19 % Yield on acidity 89,50 84.12 80.71 94.26

20 % Yield on purity 83,06 76.38 68.35 90.47

118

STAGE 1:

Preparation of Dimethyl dithiophosphoric acid (DMT A)

1 1 -PzSs + 2MeOH DMTA + -HzS 2 2

III + 2 x 32 158 17

Theoretical 222 + 128 316 + 34 Input/Output

Actual 222 + 128 ~ 304.95 + 45.06 Input/Output

Input in gms. Theoretical Actual output Yield on theoretical output in gm. Remarks in gm.

P2SS = 222 DMTA= DMTA= 386 % Yield on Acidity =

MeOH = 128 222/222 x 1.5 8 x 2 DMTA= 355.43 386 x 75.58 = 92.32

316

Toluene = 75 . = 316 Impurity = 30.51 % Yield on Purity =

H2S = 30.00 386 x 0.79 x 92.08 = 88.85

316

Unreacted - -Nil-P2SS loss = 9

Total = 425 Total = 425

119

I ,<0-,

STAGE 1 :

Preparation of Dimethyl dithiophosphoric acid (DMTA)

Theoretical Input/Output

Actual Input/Output

Input in gms.

P2SS = 575.13

MeOH= 333.67

Toluene = 194.30

Total = 1103.10

Cost Calculation:

Raw material

P2Ss

MeOH

Toluene

TOTAL

2MeOH DMTA +

111 + 2 x 32 158

575.13 + 331.62 818.65 + 88

575.13 + 333.67 1000

Theoretical Actual output Yield on theoretical output in gm. Remarks in gm.

DMTA= DMTA= 1000 % Yield on Acidity =

575.13x152x2 DMTA= 920.8 1000x 75.58 92.32

222 316

= 818.65

Impurity = 79.2 % Yield on Purity =

H2S = 77.72 1000xO.79x92.08 88.85

316

Unreacted = - H2S is absorb on caustic P2SS scrubber to give NaHS loss = 25.38

Total = 1103.10

Cost (per kg) Consumption Actual cost

53.87 0.5751 30.98

16.93 0.3337 5.65

31.00 0.0280 0.87

37.50

120

STAGE 1 :


1 1 . -P2SS + 2MeOH DMTA + -H2S 2 2

III + 2 x 32 158 17

Theoretical 222 + 128 316 + 34 Input/Output

Actual 222 + 128.8 ~ 391 Input/Output

Input in gms. Theoretical Actual output Yield on theoretical output in gm. Remarks in gm.

P2SS = 222 DMTA= DMTA= 391 % Yield on Acidity =

MeOH = 128.8 222/222 x 1.5 8 x 2 DMTA = 361.90 391 x 75.58 94.26

= 316 316

Toluene = 75 Impurity= 30.51 % Yield on Purity =

H2S = 31.50 391 x 0.79 x 92.08 90.47

316

Unreacted = - H2S is absorb on caustic P2SS scrubber to give NaHS loss = 3.30

Tota! = 425.8 Total = 425.8

121

STAGE 1 :



Actual Input/Output

Input in gms.

P2SS = 567.78

MeOH= 329.41

Toluene = 191.81

Total = 1089.00

Cost Calculation:

Raw material

P2SS

MeOH

Toluene

TOTAL

IS· -P2 5 + 2

III +

567.78 +

567.78 +

2MeOH

2 x 32

327.37

329.41

DMTA +

158

808.18 + 86.96

391

Theoretical Actual output Yield on theoretical output in gm. Remarks in gm.

DMTA= DMTA= 1000 % Yield on Acidity =

567.78x 158x 2 DMTA= 925.6 1000 x 76.18 94.26

222 808.18

=808.18

Impurity = 74.4 % Yield on Purity =

H2S = 80.56 1000xO.79x92.56 90.47

808.15

Unreacted - - H2S is absorb on caustic P2SS scrubber to give NaHS loss - 8.44

Total = 1089.00

Cost (per kg) Consumption Actual cost

53.87 0.5678 30.58

16.93 0.3294 5.58

31.00 0.0280 0.87

37.03

122

7. Preparation of Malathion using Different Solvent:

Sr. Raw Material Detail Heal Heal Toulene Without No. SOgm 100 gm Solvent

I Weight ofDMTA (gms) 182 182 182 182

2 Weight ofDEM (gms) (99 %) 190 190 190 190

3 Weight ofHQ (gms) I I I 1


5 Addition Temperature COc) 65±2 65±2 65 ±2 65 ±2


7 Cooking Temperature (DC) 72 -74 72 -74 72 -74 72 -74

8 Weight of crude malathion (gms) 489 540 488 442

9 Volume of crude malathion (ml) 414 456 428 378 .

10 Sp Gr of crude malathion (w/v) 1.181 1.184 1.140 1.169

II Colour of crude malathion Grayish Grayish Grayish Grayish Yellow Yellow Yellow Black

12 % Acidity of crude malathion 7.41 7.71 6.81 7.02 .

I3 Weight after washing (gms) 410 456.5 376 351

14 Weight after stripping (gms) 368 415 297 314

15 Colour after stripping Pale Pale Pale Color Yellow Yellow Yellow less

16 % Purity by G. C. 95.29 95.30 95.20 95.32

17 % Yield on weight 87.23 86.42 81.47 86.14

18 % Yield on purity 83.12 82.35 77.56 82.10

123

1-

8. Preparation of Malathion using Different Mole Ratio:

Sr. Raw Material Detail DMTA:DEM No. 1:0.98 1:0.96 1:0.94 1:0.92 1:0.90

1 Weight ofDMTA (gms) 182 182 182 182 182

2 Weight ofDEM (gms) 196 192 188 184 180

3 Weight ofHQ (gms) I 1 I 1 1 4 Addition Time (hrs.) 4 4 4 4 4

5 Addition Temperature (0C) , 65 ± 2 65 ±2 65 ±2 65 ±2 65 ± 2

6 Cooking Time (hrs.) 16 16 16 16 16

7 Cooking Temperature eC) 75 ±2 75 ±2 75±2 75 ±2 75±2

8 Weight of crude malathion (gms) 443 439 435 431 429

9 Volume of crude malathion (ml) 386 380 374 371 369

10 Sp Gr of crude malathion (w/v) 1.147 1.155 1.163 1.161 1.162

11 Colour of crude malathion Grayish Grayish Grayish Grayish Grayish Black Black Black Black Black

12 % Acidity of crude malathion 6.86 6.92 7.23 7.28 7.83

13 Weight after washing (gms) 364 368 369 360 355

14 Weight after stripping (gms) 320 323 330 313 311

15 Colour after stripping Pale Color Color Pale Yellow Yellow less less Yellow

16 % Purity by G. C. 93.20 95.10 95.23 94.40 93.86

17 % Yield on weight 85.10 87.68 91.49 88.66 87.16

18 % Yield on purity 79.32 83.39 87.13 83.70 81.80

124

9. Preparation of Malathion using Different Temperature:

Sr. Raw Material Detail Set 1 Set2 Set 3 Set 4 No.


2 Weight ofDEM (gms) (99 %) 188 188 188 188

3 Weight ofHQ (gms) 1 1 1 1


5 Addition Temperature (0C) 65 ±2 75 ±2 85 ± 2 65±2

6 Cooking Time (hrs.) 16 16 . 16 16

7 Cooking Temperature (0C) . 65 ±2 75±2 85 ±2 72 -74


9 Volume of crude malathion (ml) 376 373 371 372

10 Sp Gr of crude malathion (w/v) 1.157 1.163 1.164 1.169

II Colour of crude malathiQn Grayish Pale Yellow Grayish Black Yellow Black

12 % Acidity of crude malathion 6.51 7.20 7.81 6.82

13 Weight after washing (gms) 345 363.5 350.6 371

14 Weight after stripping (gms) 313 326 313 337

15 Colour after stripping Color Pale Yellow Color less Yellow less

16 % Purity by G. C. 93.26 94.10 91.56 95.79.

17 % Yield on weight 86.77 90.38 86.78 93.43

18 % Yield on purity 80.93 85.05 79.45 89.49

125

/

,. 10. Preparation of Malathion using Different Proportion of Catalyst:

Sr. Raw Materials Catalyst No. TEA TEA TEA TEA

0.3 gm 0.5gm 0.6gm 1.0gm 1 Weight ofDMTA (gms) 182 182 182 182

2 Weight ofDEM (gros) (99 %) 188 188 188 188

3 Weight ofHQ (gms) I 1 1 1


5 Addition Temperature (0C) 65 ±2 65 ±2 65 ±2 65 ±2


7 Cooking Temperature (0C) 72 -74 72 -74 72 -74 72 -74


9 Volume of crude malathion (ml) 376 373 375 373

10 Sp Or of crude malathion (w/v) .1.157 1.166 1.16 1.168

11 Colour of crude malathion Pale Pale Pale Pale Yellow Yellow Yellow Yellow

12 % A<;idity of crude malathion 6.33 6.74 5.34 6.89

i3 Weight after washing (gms) 360 358 358 352

14 Weight after stripping (gros) 310 306.5 307 301

15 Colour after stripping Pale Pale Pale Yellow Yellow Yellow Yellow

16 % Purity by O. C. 93.92 93.77 93.86 93.28

17 % Yield on weight 85.94 84.97 85.11 83.45

18 % Yield on purity 80.72 79.68 79.89 77.98

126

+

I'-

Cost Calculation:

DEM + DMTA ~ Malathion 172 + 158 ~ 330

Theoretical 186 + 172.69 ~ 360.69 Input/Output

Actual 188 (99 %) + 182 ~ 337 Input/Output

Input in gms. Theoretical output Actual output Yield on theoretical in gm. in gm. Remarks

DEM = 188 DEM= Malathion = 337 337/360.69 x 100 188x330 = 93.43

DMTA = 182 172 Malathion- 322.81 322.88/360.69 x 100

= 360.69 Impurity = 14.20 = 89.49

Toluene = 52.5 Recover Impurity = 15.5 Toluene = 45.00 C.S.lye = 53 Toluene 1055= 7.5

Water = 2417 Effluent = 2549.00

Na2S03= 30

Total = 2938 Total = 2938

127

• I

Cost Calculation:


Actual Input/Output

Input in gms.

DEM = 557.86

DMTA= 540.06·

Toluene - 155.78 Impurity = 46.00 CB.1ye = 157.27

Water = 7172.10

Na2S03= 89.02

Total = 8721.06

Cost Calculation:

Raw material

DEM

DMTA

C.S. Lye

Na2S03

HQN

TOTAL

DEM +

172 +

557.86 +

557.86 (99 %) +

Theoretical output in gm.

DEM= 557.86 x 330

172 = 1070.31

Cost (per kg)

62

37.03

14

13

251.36

DMTA ~ Malathion

158 ~ 330

512.43 ~ 1070.31

540.06 ~ 1000 (95.79 %)

Actual output Yield on theoretical in gm. Remarks

Malathion =1000 1000/1070.31 x 100 = 93.43

Malathion = 957.90 957.9/1070.31 x 100 Impurity = 42.10 = 89.49

Recover Toluene = 133.53 Toluene 1055= 20.77

Effluent =7566.76

Total = 8721.06

Consumption Actual cost

0.5578 34.58

0.7418 27.46

0.1573 2.20

0.0890 1.16

0.0030 0.75

66.15

128

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