ESTERSESTERS

C

O

R OR

Acetic acid + ethanol

Methanol + Salicylic acid

Ethanol +Benzoic acid

Aliphatic Aromatic Aromatic

Ethyl acetate Methyl salicylate Ethyl benzoate

C

O

H3C OC2H5

OH

COOCH3

COOC2H5

Ethyl acetateEthyl acetate Methyl salicylateMethyl salicylate Ethyl benzoateEthyl benzoate

Physical properties:Physical properties:

State

Color

Odor

Inflammability

Change in appearance

Change in odor

Color imparted to the flame

Residue

comment

Liquid, oily, true

Fruity odor Vicks odor

Colorless

Ignition test:Ignition test:

Inflammable, non luminous, non smoky

No change

Characteristic odor

The compound is aliphatic

Inflammable, luminous, smoky

All volatilization

No change

No residue

The compounds are aromatic

Miscibility: Miscibility:

Ethyl acetateEthyl acetate Methyl salicylateMethyl salicylate Ethyl benzoateEthyl benzoateH2O

L.p.

Dil. HCl

10%NaOH

Conc. H2SO4

Comment:

All immiscible

.: All are neutral compounds

All immiscible

All immiscible

All immiscible

Preliminary test:Preliminary test:

Ethyl acetateEthyl acetate Methyl salicylateMethyl salicylate Ethyl benzoateEthyl benzoate Soda limeSoda lime

30% NaOH30% NaOH

On cold:On cold:

On hot:On hot:

FeClFeCl33

On cold:On cold:

On hot:On hot:

Conc. HConc. H22SOSO44

On cold:On cold:

On hot:On hot:

Not done ( for solid only)

Not done

Not done

No reaction in all

No reaction in all

No reaction

Violet color in ethanol layer

White ppt of Na-salicylate No reaction

No reaction No reaction

No reaction No reaction

No reaction No reaction

General test :General test :

Ethyl acetateEthyl acetate Methyl salicylateMethyl salicylate Ethyl benzoateEthyl benzoate

1. Hydroxylamine HCl test:1. Hydroxylamine HCl test:Ester + hydroxylamine HCl ((white solid)) + 10% NaOH until fussion clear solution after cooling + Dil. HCl + 2 drops FeCl3

Reddish brown color Reddish violet color Reddish brown color

2. Hydrolysis test:2. Hydrolysis test:

2 ml ester + 20ml 10% NaOH Reflux 30 min. Distillation

Distillate (( alc.)) Residue (( acid))Ethanol + Acetic acid Methanol + Salicylic acid Ethanol +Benzoic acid

Specific test :Specific test :

Ethyl acetateEthyl acetate Methyl salicylateMethyl salicylate Ethyl benzoateEthyl benzoate

Ethyl acetate is Ethyl acetate is lighterlighter than Hthan H22OO

Ethyl acetate + H2O shaking

Methyl salicylate+ H2O shaking

Ethyl benzoate + H2O shaking

Methyl salicylate is Methyl salicylate is heavierheavier than H than H22OO

Ethyl benzoate is Ethyl benzoate is heavierheavier than H than H22OO

IRLocationLocation CommentComment

Ethyl acetateEthyl acetate

Methyl salicylateMethyl salicylate

Ethyl benzoateEthyl benzoate

1750 – 1735 cm -1

< 3000 cm -1

C=O stretching band

C=O stretching band1750 – 1735 cm -1

CH aliphatic stretching band

CH aliphatic stretching band

> 3000 cm -1 CH aromatic stretching band

1750 – 1735 cm -1 C=O stretching band

< 3000 cm -1 CH aliphatic stretching band

> 3000 cm -1 CH aromatic stretching band

3400 – 3200 cm -1 -OH stretching band

< 3000 cm -1