SU419505A1 - METHOD OF OBTAINING DIETHYLACEGAL a-CHLOROCROLEIN - Google Patents

Description

This invention relates to a process for the preparation of diethyl acetal α-chloroacrolein, which has an active double bond and a protective aldehyde group in the molecule and is an important product in organic synthesis.

A known method of producing diethyl acetal cc-chloroacrolein by reacting 1,1-di.chloro-ethoxycyclopropane with ethyl alcohol in the presence of sodium ethoxide as a catalyst when heated to 80-90 ° C, and isolating the target product by known methods.

In a known manner, a-chloroacrolein diethyl acetal is obtained with a yield of 73%, contaminated with products of further transformations; besides using alkali metal.

It is proposed instead of sodium ethylate as a catalyst to use potassium fluoride and conduct the process at a temperature of 130-170 ° C. The yield of a-chloroacrolein diethyl acetal is increased to 92-97%.

Example. 15.5 g of 1,1-dichloro-2-ethoxycyclopropane, 23.0 ml of ethyl alcohol, 15.5 g of potassium fluoride are placed in a sealed ampoule and heated for 4 hours at 160 ° C. After cooling, the contents are filtered off from the precipitate, the precipitate is washed with a small amount of alcohol, the filtrate is re-heated, and 15.2-16.0 g of diethyl acetal a-chloroacrolein are obtained, i.e. 155 ° C, ° 1,4438 each. Literary data: t. 38 ° C (8 mm

20

Hg Art.). 1.4466 each. According to GLC, the product is approximately 99.5% pure.

Subject invention

The method of producing α-chloroacrolein diethyl acetal by reacting 1,1-Dnchloro-2-ethoxycyclopropane with ethyl alcohol when heated in the presence of a catalyst with the release of the target product by known agents, so that, with the aim of increasing The yield of the target product is used; potassium fluoride is used as a catalyst and the process is carried out at a temperature of 130-170 ° C.