CA1049035A - Process for the preparation of triesters and products thus obtained - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE:

A process for the preparation of triester of the formula:

wherein R is an alkyl radical of 1 to 5 carbon atoms consisting in reacting a compound of the type:

Description

~049035 The present invention relates to a process for the preparation of triesters with formula:

OCOR OCOR
H
C -- C -- H

COR
wherein R is an alkyl radical of 1 to 5 carbon atoms.
Such products are useful as intermediates for organic synthesis, such as for instance for the preparation of -hydroxy-aldehydes, ~-acyloxy-(or aryloxy)-aldehydes or ~-hydroxy-aminoacids.
The process according to the invention, consists in reacting compounds of the type H Y

H ~ ~ H

\
O\ /0 ~~ ' ' .

20 Y i8 an halogen atom or a radical OCOR, with an anhydride of a carboxylic acid RCOOH, and with that acid and an alkaline , or alkaline earth metal salt thereof at a temperature ranging from 100 to 250C and at such a pressure as to maintain the reaction mixture in a liquid phase. The invention will be now better understood with reference to the following non restrictive examples. .

Preparation of 1,1,2-triacetoxyethane from monochloroethylen-- 1 - ~

~ ....... . .
~ : . . :. . .

carbonate To 30 ml of glacial acet~c acid, 3.30 g (27 mmoles) of monochloroethylencarbonate, 0.50 g (56 mmole~) of anhydrous .
potassium acetate and 2.65 ml (28 mmoles) of acetic anhydride ~ere added and the mixture was heated to reflu~ for 40 hours under 3tirring in a nitrogen blanket. A gas chromatography (through internal standard, styrene) showed a yield Or 85%
of 1,1,2-triacetoxyethane. The reaction mixture, cooled to room temperature, was diluted with 70 ml methylene chloride.
~he precipitated salt3 were removed by filtration. The preci-pitate was washed with methylene chloride and the ~iltrate ¢ollected and drled under ~acuum on a rotating evaporator. The residue, diluted in methylene chloride is warmed and treated wlth acti~e carbon, filtered. ~he acti~e carbon was washed with a small amount of solvent and the sol~ent remo~ed under ~acuum from the collected filtrates.
~ residue Or 5.08 g was obtained, with a chromato-graphy puritg of 90% (corresponding to a yield of 83% in pure produot). ~he product wa~ further purified by distillation.
The 1,1,2-triacetox~-ethane was distilled at 112-114C/2 mmHg (~50C bath).
4.13 g Or product pure at the chromatography test (yield 75%) and with a melting point of 48-50C were obtained.

Preparation of 1.1.2-triacetoxyethane from monoacètoxreth~lene carbonate It was prepared in a manner similar to the prepa-a-~ion of monochloroethylencarbonate according to example 1, except that the quantity Or potassium a¢etate utilized WaB
halfed. ~he yields obtained were similar.
~he potassium a¢etate can also be u~ed e~en in 09~30 3 5 catalytic quantities, but the reaction 18 much slower and the yleld~ do not exceed 30-40%.

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Claims (3)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the preparation of triester of the formula:

wherein R is an alkyl radical of 1 to 5 carbon atoms, consisting in reacting a compound of the type:

wherein Y is an halogen atom or represent a -OCOR radical with an anhydride of a carboxylic acid RCOOH wherein R has the above meaning, and with that acid an alkaline or alkaline earth metal salt thereof.

2. A process according to claim 1, characterized in that the reaction is carried out at a temperature comprised between 100 and 250°C.

3. A process according to claim 1 or 2, characterized in that the reaction is carried out at such a pressure as to maintain the reaction mixture in a liquid phase.