PROCEDE POUR LA PREPARATION DE TRIESTERS ET PRODUITS OBTENUS PAR CE PROCEDE

PROCESS FOR THE PREPARATION OF TRIESTERS AND PRODUCTS THUS OBTAINED

Abrégé anglais

ABSTRACT OF THE DISCLOSURE:

A process for the preparation of triester of the
formula:

Image

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


Image


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 and an alkaline or alkaline earth
metal salt thereof. The so obtained products are useful as
intermediates for organic synthesis such as the preparation of
?-hydroxy-aldehydes, ?-acyloxy-(aryloxy)-aldehydes or
.beta.-hydroxy-aminoacids.

Revendications

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:

Image


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


Image


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.

Description

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

OCOR OCOR
H
C -- C -- H
01




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. .
EXAMPLE 1
Preparation of 1,1,2-triacetoxyethane from monochloroethylen-




- 1 - ~




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

1049035
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.
EXANPLE 2
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%.




: . .' ' .
. ' '' .


'
'. . '~ ~.
.~ , .,
~,~
,~
..,~
,:
~'" '' ' '.
' ,:
,


~ . ~



.i . , .
. :,.'...
.. .. . . .
. .: . . ,