JOURNAL OF POLYh&ER SCIENCE: PAHT A-1 VOL. 5, 2547-2556 (1967)

Alkyl Vinyl Esters of Brassylic (Tridecanedioic) Acid*

SHU-PEI CHANG, THOMAS K. MIWA, and IVAN A. WOLFF, Northern Regional Research Laboratory, Northern Utilization Research and

Development Diwision, Agricultural Research Service, United States Department of Agriculture, Peoria, Illinois 61 604

synopsis Brassylic acid was partially estersed a t 77°C. in toluene solution with ethyl, Zmethyl-

pentyl, or nonyl alcohol and with ptoluenesulfonic acid u d as catalyst. Half-esters were isolated from the respective reaction mixtures in yields of 28, 34, and 32% after re- action times of 2,6, and 8 hr. Both recovered brassylic acid and byproduct dialkyl ester were successfully used as starting materials in subsequent esterifications. Consequently, conversion of starting materials to half-wter would be increased in a process that in- volved continuous recycling of byproducts. Alkyl hydrogen brassylates were vinylated at 165OC. for 8 hr. with acetylene a t 360 psig. The zinc salt generated in situ from zinc oxide served as catalyst and toluene as solvent. Yields were 80448% and purities of products were 9445%. Samples of Zmethylpentyl vinyl brrtssylate and nonyl vinyl brassylate of much higher purity were obtained by preparative gas-liquid chromatog- raphy or molecular distillation. Physical properties and experimental conditions for gas- liquid chromatographic analyses of both the alkyl hydrogen and alkyl vinyl brassylates are reported.

INTRODUCTION

The suitability of alkyl vinyl esters of dicarboxylic acids as comonomers for internally plasticized poly(viny1 chloride) has been examined.' One factor that affects the internal plasticization by vinyl esters of monocar- boxylic acids is the chain length of the acid.2 The longest straight-chain dicarboxylic acid available in commercial quantities as dimethyl ester3 is brassylic (tridecanedioic) acid. This product is obtained from erucic (cis-13-docosenoic) acid. Currently erucic acid is derived from imported rapeseed oil, but a richer source is a newly developed domestic oilseed crop, Crambe abyssinica Hochst. ex R. E. Fries, the seed oil of which contains 55-607& of erucic acid as the glyceride ester.4 Since dialkyl brassylates are excellent low-temperature plasticizer^,^ building alkyl vinyl brassylates into a polymer as internal plasticizers to avoid leaching and volatilization might provide useful products.

Chemistry, Miami Beach, Florida, April 9-14,1967. * Presented a t the 153rd American Chemical Society Meeting, Division of Polymer

2547

254a S.-P. CI-IANG, T. K. MIWA, I. A. WOLFF

Among the dialkyl brassylates, the bis(2-methylpentyl) ester is the best plasticizer when all properties are copsidered. Accordingly, 2-methyl- pentyl vinyl brassylate was selected as one of the comonomers to be pre- pared. The other two, ethyl vinyl and nonyl vinyl brassylates, were chosen to determine the effects of a small and a large saturated alkyl. Copolymerization of these alkyl vinyl brassylates with vinyl chloride and the internal plasticization achieved will be reported later.

Alkyl hydrogen esters of short-chain dicarboxylic acids have previously been prepared from: (a) dicarboxylic acids by half-esterificatione or equili- bration,' ( b ) dialkyl esters by half-saponification,* and (c ) monomeric anhydrides by alcoh~lysis.~ Alkyl vinyl esters have been made from alkyl half-esters by direct vinylation,1° by transesterification," or via the cor- responding chlorides by reaction with the mercuric derivative of acetalde- hyde.8 Alkyl vinyl esters have also been produced from salts of alkyl half- esters by reaction with vinyl haloformates.12

In this investigation, half-esterification followed by vinylation with acetylene was the most convenient route to the desired alkyl vinyl esters of the long-chain dibasic acid, brassylic acid.

EXPERIMENTAL

Materials and Analytical Methods Brassylic acid from ozonolysis of erucic acid13 was recrystallized twice

from xylene to a purity of 99.0%. Ethanol was treated with sodium metal and distilled at atmospheric pressure to give a purity of 98.7y0. BMeth- ylpentanol (Union Carbide) and nonanol (Aldrich) were fractionally dis- tilled to respective purities of 99.8 and 99.9%. For the purified 2-methyl- pentanol, nz = 1.4160 (reported14 1.4172), and for nonanol, ng = 1.4388 (reported'5 1.4388). The purities of starting materials and products were determined by gas-liquid chromatography (GLC) under conditions given in Table I. Thin-layer chromatography (TLC) was conducted with silica gel G plates and hexane-ethyl ether (80/20) as the solvent. Infrared absorption spectra of 5% solutions of half-esters in carbon tetrachloride were obtained on a Perkin-Elmer Model 337 Infracord spectrophotometer ; spectra of alkyl vinyl esters were secured from the compounds as liquid films. Neutralization equivalents," saponification equivalents, and iodine were determined by conventional methods.

Preparation of Half-Esters

Details of preparation and purification of each half-ester are given in Table 11. The following general procedure was used. A 1-liter, three- necked flask equipped with a condenser, mechanical stirrer, and thermom- eter was placed in n water bath maintained at 77°C. Into the flask were introduced 48.86 g. (0.2000 mole) of brassylic acid, 1.26 g. (0.0066 mole) of ptoluenesulfonic acid monohydrate (Eastman), 0.2000 mole of the ap-

BRASSYLIC (TRIDECANEDIOIC) ACID

TABLE I Gas-Liquid Chromatography of Brassylic Acid Esters and

Their Starting Materials

2549

Column tem-

Liquid pera- Equip- Compound ECIp phaseb ture, "C. mento

Ethanol - Apiezon L 20% 60 A Ethyl brassylate 17.0 Apiezon L 10% 220 B Ethyl methyl brassylat,e 16.3 Apiezon L 10% 220 B Methyl brsssylate 16.7 Apiezon L 10% 220 B Methyl brassylate 15.7 Apiezon L 10% 220 B Methyl brassylate 20.3 Resoflex 446 3 % 208 C Methyl 2-methylpentyl brassylate 23.3 Resoflex 446 3% 208 C

brassylate 29.6 Resoflex 446 3% 208 C 2-Methylpentyl brassylate 26.8 Resoflex 446 3% 208 C 2-Methylpentyl vinyl brassylate 23.6 Resoflex 446 3% 208 C 2-Methylpentyl vinyl brassylate 23.6 Resoflex 446 15% 205 D Nonanol - Apiezon L 10% 220 B

2-Methylpentanol - Apiezon L 20% 8&160 A 2-Methylpentyl hydrogen

Nonyl brassylate 31.0 JXR 370 115-330 E Nonyl methyl brassylate 24.0 JXR 3% 115-330 E Nonyl vinyl brassylate 24.5 JXR3% 115-330 E Nonyl vinyl brassylate 24.5 JXR 3% 110-320 F Vinyl brmylate 20.8 Resoflex 446 3% 208 C

Equivalent chain length based on methyl n-alkanoates as reference.' Linear plot of retention time versus ECL used for programmed temperature GLC.

b Solid support for Apiezon L = acid-washed, silylated, 60/80-mesh Chromosorb W; Reaoflex 446 = acid-washed, 60/80-mesh Celite 545; JXR = 100/120-meah Gas Chrom Q (Applied Science).

in. stain- less steel coiled column, helium 25 ml./min./50 psig; B = Burrell Model K-5, thermal conductivity detector, 275 X 0.6 cm. glass U-column, helium 40 ml./min./40 psig. (car- rier gas reduced to 10 ml./min./lO psig. for nonanol); C = Burrell Model K-5, thermal conductivity detector, 125 X 0.3 cm. glass U-column, helium 30 ml./min./30 psig. ; D = Aerograph Autoprep Model A-700, thermal conductivity detector, 5 f t . X in., stainless steel coiled column, helium 60 ml./min./50 psig., 0.1 ml. sample per injection; E = F&M Model 810, flame ionization detector, 2 f t . X in., stainless steel column, helium 100 ml./min./100 psig; F = F&M Model 810, thermal conductivity detector, 2 f t . X l / 8 in., stainless steel column, helium 35 ml./min./40 psig., 0.1 ml. sampler per injection.

0 Equipment: A = F&M Model 810, flame ionization detector, 10 ft. X

propriate alcohol, and 500 ml. of toluene. The reaction mixture was heated for the time specified in Table 11, and the products were then cooled overnight at the temperatures indicated. The precipitate, predominantly brassylic acid, was removed by filtration. The half-ester content in the precipitate was 10-12,343, and 1-2% for ethyl, 2-methylpentyl, and nonyl hydrogen brassylate, respectively. The small quantity of brassylic acid remaining in the filtrate was removed by passing the filtrate through a 4.4- cm. I.D. column containing 150 g. of silicic acid and washing the column with 350-400 ml. of toluene. After adjustment to the volume given in

TA

BL

E I1

Prep

arat

ion

of B

rass

ylic

Aci

d Halt-Esters

Este

rific

atio

n C

ryst

alliz

atio

n T

empe

ratu

re

~

for

Vol

ume

cool

ing

of Pr

oduc

t?

Yie

ld, %

A

lcoh

ol

Tim

e an

d to

luen

e T

empe

m

char

ged,

at

77"

C.,

filtra

tion,

so

lutio

n,

ture

, Time,

Puri

ty of

H

alf-

este

r g.

hr

. "C

. d.

"C.

hr.

AB

C

A,

%

Eth

yl h

ydro

gen

brae

syla

te

9.21

2

1

500

- 78

4

28

48

99

.1

Non

yl h

ydro

gen

bras

ayla

te

28.8.5

8 25

12

50

- 18

16

32

99.5

ZM

ethy

lpen

tyl h

ydro

gen

bras

ayla

te

20.4

3 6

- 18

500

- 78

4

34

42

42

99.2

A, F

rom

fres

h starting m

ater

ials

; B

, total fr

om o

ne fr

esh run

and

one r

ecyc

ling

of th

e re

cove

red

bras

sylic

aci

d; C

, total f

rom

one

fres

h run

and

one

recy

clin

g of

both

the

reco

vere

d br

asay

lic a

cid

and

the

crud

e di

slky

l bra

asyl

ate.

U

? e P r 1

B W S Y L I C (TRIDECANEDIOIC) ACID 2551

Table 11, the combined eluate was cooled to the crystallization temperature (Table 11). The alkyl hydrogen brassylate which crystallized was filtered is the cold (1°C.) and washed with cold (crystallization temperature) toluene. The filtrate from the crystallization contained dialkyl brassylate (6040%) and unrecovered alkyl hydrogen brassylate (15-35%).

The brassylic acid-rich precipitate was recycled without affecting the yield by following the foregoing procedure after adding fresh brassylic acid and alcohol to give a total of 0.200 mole each of the brassylic and alcoholic moieties. In one instance the crude dialkyl brassylate was also included as “starting material” in a recycling experiment. Yields B and C in Table I1 were calculated from the total brassylic acid employed. This total in- cluded the brassylic acid used in the original esterification and that added as “make-up” starting material in the recycling experiment.

Analytical samples of solid ethyl and nonyl hydrogen brassylates were prepared by three recrystallizations from n-hexane. An analytical sample of liquid Zmethylpentyl hydrogen brassylate was made by silicic acid column chromatography for which chloroform was used as solvent. Sam- ples were analyzed for purity by TLC and by GLC of their corresponding methyl esters prepared by reaction with diaaomethane (Table I). Physical constants were determined by conventional methods.

Viylation The following general procedure was employed: A 3 0 0 4 . stainless-

steel autoclave equipped with a magnetic stirrer and cooling coil was charged with 0.61 g. (0.0075 mole) of zinc oxide (Baker analyzed reagent), 0.09oO mole of half-ester, and a weight of toluene equal to 83% of the half- ester used. The autoclave was inserted into an electric heater and flushed with acetylene. Vinylation proceeded with stirring at 165°C. under 360 psig. maintained by periodically refilling the autoclave with acetylene. The reaction was stopped after 8 hr., during which time sufiicient acetylene had been absorbed to provide an 8040% conversion. Products were re- moved from the autoclave and filtered. To remove traces of catalyst and unreacted starting material, the filtrate was introduced into a 3.2-cm. I.D. column packed with a mixture of 50 g. of alumina, 25 g. of Celite, and 25 g. of active carbon and was eluted with 400 ml. of toluene. Upon removal of solvent a faint yellow liquid remained. Products were 94-95% pure, and yields were 80-88%.

For characterization, 1 g. samples of 2-methylpentyl vinyl brassylate and nonyl vinyl brassylate were further purified by preparative GLC (Table I). Larger samples (6-12 g.) of the pure compounds were collected after four or five passes through an ASCO 50 rota-film molecular still. For polymerization 100 g. quantities of 2-methylpentyl vinyl brassylate were freed of the crosslinking agent, divinyl brassylate, by its selective removal from the bulk product in a single pass through the molecular still. Further purification of ethyl vinyl brassylate was, however, not achieved by either molecular distillation, preparative GLC, or fractional crystallization.

2552

0

0.1

0.2 0

c 2 0.1 - 0.2

0.3

0.4 0.5

S.-P. CHANG, T. K. MIWA, I. A. WOLFF

I I I I I I L 1% - r

- 4 If

- I = B

- - - - I

i I I I I

Fig. 1. Uptake of acetylene during vinylation of (A) ethyl hydrogen brassylate, (a), Zmethylpentyl hydrogen brassylate, and (0) nonyl hydrogen brassylate.

The final highly purified samples were examined by TLC to confirm the absence of any contaminating polymers.

RESULTS AND DISCUSSION

To avoid excessive discoloration during half-esterification a temperature (77°C.) below reflux (110°C.) was used. The reaction times were the minimum times at which an equilibrium mixture of unreacted brassylic acid, half-ester, and dialkyl ester (in 1 :2: 1 molar ratio) was achieved in

Fig. 2. chloroform);

TABLE

I11

Ana

lyse

s and

Phy

sica

l Con

stan

ts of

Bra

ssyl

ic A

cid

Est

ers

Neu

tral

izat

ion

Sapo

nific

atio

n Io

dine

eq

uiva

lent

eq

uiva

lent

va

lue

Mel

ting

3 Sp

.gr2

: h

E

ster

Pu

rity

, %

Cal

cd.

Foun

d C

alcd

. Fo

und

Cal

cd.

Foun

d po

int,

"C.

ng5

E! E

thyl

hyd

roge

n

SMet

hylp

enty

l

Non

yl h

ydro

gen

Eth

yl v

inyl

bra

ssyl

ate

93.7

85

.1

81.8

21

.O-2

1.8

1.44

85

0.95

32 2

bras

syla

te

99.9

71

.6

70.0

5.

8-6.

3 1.

4506

0.

9320

-

* Rep

orte

d m

eltin

g po

ints

56-

57°C

.,22 4

2-43

OC

.18

z 3

Non

yl v

inyl

bra

ssyl

ate

99.4

64

.0

63.2

23

.8-2

4.3

1.45

28

0.92

40

g

bras

sy la

te

99.6

27

2.4

272.

8 13

6.2

136.

9 60

.0-6

1.0*

hydr

ogen

bra

ssyl

ate

99.8

33

1.3

328.

5 16

4.3

164.

0 22

.5-2

4.5

1.45

09

0.95

02

c br

assy

late

99

.9

370.

6 37

4.0

185.

3 18

6.8

50.0

-51.

0 Ei

ZM

ethy

lpen

tyl v

inyl

n

El hl

en

en

W

2554 S.-P. CHANG, T. K. MIWA, I. A. WOLFF

preliminary experiments. Although the half-ester content of the reaction mixture at, equilibrium is SO%, continuous recycling of byproducts should eventually give essentially qiiantitative conversion of brassylic acid to half-esters (Table 11). Because colored impurit,ies accumulated in the diester fraction and interfered with the subsequent crystallization of half- ester, yield C in Table I1 is no greater than yield B. To take full advantage of the potential yield increase by recycling, a purification step to remove the contaminants should be incorporated.

While our work was in progress, Freidlin et al.11s20 reported preparation of alkyl vinyl esters of succinic (CS, glutaric (CJ, adipic (C,), azelaic (C,), and sebacic (GO) acids via transesteriiication. They also mentioned suc- cess in direct vinylation of alkyl hydrogen adipate but failure with alkyl hydrogen succinate.21 Our direct vinylation of half-esters gave satisfactory results. The procedure we used involves preparation of the catalyst (zinc salt of the half-ester) in situ. Acetylene uptake ceased before the end of the 8 hr. reaction time when ethyl and 2-methylpentyl half-esters were the starting materials, but not with the nonyl hydrogen brassylate. Neverthe- less, the yields of alkyl vinyl brassylates were substantially the same in all three reactions. Even though the starting materials (half-esters) contained no brassylic acid, all vinylation products contained 1-2% divinyl brassylate, as well as 3-6% dialkyl brassylate. Where differences in molecular weight were great enough, these ,impurities could be removed by molecular dis- tillation or preparative gas-liquid chromatography. The pure ethyl vinyl brassylate was, however, not obtainable by these methods because of its similarity in molecular weight to divinyl and diethyl brassylates.

The reported yields are an average of at least five preparations, except for yield C (Table 11) which is an average of two preparations. The listed purities are the alkyl hydrogen brassylate and alkyl vinyl brassylate con- tents determined by gas-liquid chromatography (see Table I). The trace contaminants in the half-ester preparations were half-esters of the homolo- gous undecanedioic and pentadecanedioic acids. TLC of the alkyl vinyl brassylate samples showed no contamination by polymers. The chemical constants listed in Table I11 and the C and H analysis observed for the analytical samples were in good agreement with their calculated values. All half-esters and alkyl vinyl esters were soluble (0.1 g./ml.) in acetone, acetonitrile, carbon tetrachloride, chloroform, dioxane, ethyl ether, n- hexane, methanol, and toluene but were insoluble in water. The infrared spectra of half-esters showed a double carbonyl peak at 5.85 p (carboxylic acid, stronger) and 5.75 p (alkyl ester, weaker). The spectra of alkyl vinyl ester had a vinyl peak at 6.08 p (C=C stretch) and a double carbonyl peak at 5.78 p (alkyl ester) and 5.70 p (vinyl ester), the shorter wavelength of the latter being due to the electron-withdrawing property of the vinyl group.24 Another absorption peak of the vinyl group at 3.24 p (CHZ asym- metric stretch) was seen, but it was weak. The strength of the methylene peak at 3.42 p increases as the number of methylene groups increases from the ethyl to nonyl esters.

BRASSYLIC (TRIDECANEDIOIC) ACID 2553

We express our appreciation to R. L. Reichert for vinylation, J. W. IIagemann for gas chromatographic analyses, Mw. C. E. McGrew for microanalyses, R V. Madrigal for brasaylic acid purification, and W. H. Tallent for his advice.

Reference to commercial prodiicts does not, imply endmrenient by the lJnited States Department of Agriculture over similar products not mentioned.

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3. Chem. Eng. News, 45, No. 41, 101 (1965). 4. I. A. Wolff, Crops Soils, 18, No. 4, 10 (1966). 5. H. J. Nieschlag, J. W. Hagemann, I. A. Wolff, W. E. Palm, and L. P. Witnaner,

6. S. Swann, Jr., R. Oehler, and R. J. Buswell, in Organic Syntheses, Coll. Vol. II,

7. E. Fourneau and S. Sabetay, Bull. Soc. Chim. France, 43,859 (1928). 8. F. N. Stepanov and T. N. Veretenova, J . Org. Chem. USSR (Eng. transl.), 1, 1414

9. J. C w n , in Organic Syntheses, Coll. Vol. IIZ, E. C. Homing, Ed., Interscience,

Swern, Ind. Eng. Chem., 47.472 (1955).

Znd. Eng. Chem. Prod. Res. Develop., 3,146 (1964).

A. H. Blatt, Ed., Interscience, New York, 1943, p. 276.

(1965).

New York, 1955, p. 169. 10. 0. Nicodemus, H. Lange, and 0. Horn, U.S. Pat. 2,153,987 (1939). 11. G. N. Freidlii, A. P. Chukur, and L. I. Dzarokhokhova, J. Org. Chem. USSR

12. A. Pechukas, U.S. Pat. 2,472,434 (1949). 13. H. J. Nieschlag, I. A. WoH, T. C. Manley, and R. J. Holland, Znd. Eng. Chem.

14. F. Hovorka, H. P. Lankelma, and S. C. Stanford, J. Am. Chem. Soc., 60, 820

15. P. G. Stecher and B. M. Szafranski, The Merck Index, 7th Ed., Rahway, New Jer-

16. T. K. Miwa, K. L. Mikolajczak, F. R. Earle, and I. A. Wolff, Anal. Chem., 32,

17. A. Steyermark, Quuntitative Organic Mieroanalysis, 2nd Ed., Academic Press, New

18. C. H. VanEtten, Anal. Chem., 23,1697 (1951). 19. V. C. Mehlenbacher, T. H. Hopper, and E. M. Salee, O&iul and Tentative Me&

o h of the American Oil Chemists' Society, 3rd Ed., The Society, Chicago, Illinois, revised

20. G. N. Freidlin, S. M. Zhendodarova, N. V. Fomina, and A. P. Chukur, Zh. Obshch.

21. G. N. Freidlin, S. M. Zhendodarova, N. V. Fomina, and A. P. Chukur, J . Gen.

22. R. G. Jones, J . Am. Chem. SOC., 69,2350 (1947). 23. A. Fujita, Y. Hirose, S. Egani, I(. Shioji, Y. Wake, and H. Nakamura, J . Phurm.

24. N. B. Colthup, L. H. Daly, and S. E. Wiberley, Introduction to Infrared and Ramun

(Engl. transl.), 1, 1385 (1965).

Prod. Res. Develop., 6,120 (1967).

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sey, 1960, p. 734.

1739 (1960).

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1956, Cd 1-25.

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Spectroscopy, Academic Press, New York, 1964, p. 249.

R6SUlllb L'acide brassylique a 6th est6rifie partiellement B 77°C. en solution tolu6nique avec

l'alcool bthylique, Zmbthylpentylique, ou nonylique et en p rhnce d'acide ptolubne- sulfonique comme catalyseur. Les hemiesters ont 6t6 kol& au dbpart de leur m6lange de rbaction respectif avec des rendements de 28, 34 et 32% aprbs des du&s de rbaction de

2556 S.-P. CHANG, T. K. MIWA, I. A. WOLFY

2, 6 et 8 heures. L'acide brassylique recup& et l'ester dialcoy16 form6 comme produit secondaire, ont Bt6 utilids avec suc&s comme mat4riaw de depart pour des esGrifica- tions suhs6quenks. En condqiwnce, In conversion des mat4riaw de depart en hBmi- esters pourrait &re aiigmentke dans 1111 processus qiii comporterait le recyclige continuel des produits secondaires. Les brassylates acidev dalcoyleont 6t4 vinyl& B 165OC durant 8 heures avec de l'a&tylbne & 360 psig. Le sel de zinc engendre in situ au depart d'oxyde de zinc faisait fonction de catalyseur et le toluene btait utiliie comme solvant. Les rende- ments s'blevaient B 8crSS% et de la purete des produits atteignaient 94-95%. Des Bchantillons de vinylbrassylate de Zmethylpentyle et de nonyle de degr6 de puretk plus bled, ont Bt6 obtenus par chromatographie preparative gaz-liquide ou par distillation molBculaire. Les proprietes physiques et les conditions exphimentales pour les analyses chromatographiques gaz-liquide, B la fois des brassylates hydrogbne acide d'alcoyle et vinylalcoyle ont B t k rapportkes.

Zusammenfassung Brassylsiiure wurde bei 77°C in Toluollosung mit Xthyl- ZMethylpentyl- oder Nonyl-

alkohol mittels pToluolsulfonsiiure als Katalysator partiell verestert. Die Halbester wurden aus den entsprechenden Reaktionsmischungen in Ausbeuten von 28,34 und 32% nach Reaktionsdauern von 2, 6 and 8 h imliert. Die zuriickgewonnene Brassylsiiure und der als Nebenprodukt erhaltene Dialkylester wurden erfolgreich als Ausgangsma- terial fur weitere Veresterungen verwendet. Daher wiirde die Umwandlung der Aus- gangsprodukte in Halbester in einem Verfahren mit kontinuierlicher Wiedereinfuhrung der Nebenprodukte erhoht werden. Alkylhydrogenbrassylate wurden mit Acetylen bei 360 psig bei 165' durch 8 h vinyliert. Das in situ mit Zinkoxyd gebildete Zinksalz diente als Katalysator und Toluol al Liisungsmittel. Die Ausbeuten betrugen 8 0 4 8 % und die Reinheit der Produkte lag bei 9445%. ZMethylpentyl-vinylbrassylat- und Nonyl- vinylbrassylatproben von vie1 hijherer Reinheit wurden durch praparative Gas-Fliissig- chromatographie oder Molekulardestillation erhalten. Physikaliiche Eigenschaften und Versuchsbedmgungen fur gas-flussigchro~to~apatographische Analysen von Alkylhydm gen- und Alkylvinylbrassylaten werden angegeben.

Received January 30, 1967 Revised February 27, 1967 Prod. No. 53948