RU2584008C1 - Method of producing 2-ethyl-1,3-dioxolanes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry, particularly, to preparation of 2-ethyl-1,3-dioxolanes which are useful as solvents and components of paints and substrates in fine organic synthesis. Method comprises condensation of aliphatic dihydric alcohol with allyl ethyl ether at 80 °C in presence of H-Beta zeolite catalyst in following ratio, wt%: 35-47 alcohol; allyl ethyl ether 33-45; H-Beta zeolite 20.

EFFECT: increased output of end product with high quality.

2 cl, 1 tbl, 1 ex

Description

The invention relates to organic chemistry, specifically to the production of 2-ethyl-1,3-dioxolanes, which are used as solvents, components of paints and varnishes and substrates in fine organic synthesis. A known method of producing substituted cyclic acetals by condensation of dihydric alcohols with crotonic aldehyde at a temperature of 80 ° C in the presence of an interphase catalyst of activated cation exchange resin KU-2 or boron trifluoride etherate and hydroquinone to prevent polymerization (Bogomazova A.A., Mikhailova N.N., Zlotsky S C. Modern Chemistry of Cyclic Acetals, Preparation, Reactions, Properties - Saarbrücken: LAP LAMBERT Academic Publishing GmbH & Co. KG, 2011. - 87 a).

The disadvantages of this method are the low yield of the target product, the use of an expensive catalyst (boron trifluoride etherate), an inhibitor (hydroquinone) of the side polymerization reaction, and low selectivity for producing 1,3-dioxolane.

The technical problem, the solution of which is proposed in the present invention, is to develop a method for producing 2-ethyl-1,3-dioxolanes, characterized by an increase in the yield of the target product, using available starting ether and a cheaper catalyst.

This problem is solved in that a method for producing substituted 2-ethyl-1,3-dioxolanes by condensation of a diatomic aliphatic alcohol with allyl ethyl ether in the presence of H-Beta zeolite (formula Na ₈ (AlO ₂ ) ₈ (SiO ₂ ) ₄₀ · 24H ₂ O ) as a catalyst at a temperature of 80 ° C for 5 hours.

The process of condensation of a diatomic aliphatic alcohol with allylethyl ether is carried out at a temperature of 80 ° C in the presence of the following components, wt. %: alcohol 35-47; allyl ethyl ether 33-45; Zeolite H-Beta 20.

The method is as follows.

To carry out the reactions, a structural type BEA (Beta) type zeolite (molar ratio of SiO ₂ / Al ₂ O ₃ = 18.0) synthesized in the Angarsk Plant of Catalysts and Organic Synthesis in the NH ₄ form was used as a catalyst. The Beta zeolite was converted to H-form by heat treatment in an atmosphere of air at 540 ° C for 3 hours. Before catalytic tests, a zeolite sample was subjected to heat treatment in an atmosphere of air at 350 ° C for 4 hours (Grigoryeva, N.G. Low-molecular oligomerization of aromatic and aliphatic olefins in the presence of zeolite catalysts: dis. ... Doctors of chemical sciences. - Ufa, 2012. - 386 p.).

A mixture of alcohol, allylethyl ether and an H-Beta catalyst was heated at 80 ° C and stirred vigorously for 5 hours. At the end of the reaction, the catalyst was separated from the cooled reaction mass by filtration and the ethanol liberated was distilled off. 2-Ethyl-1,3-dioxolanes were isolated by distillation under reduced pressure.

The starting reagents must meet the following requirements:

- Allyl ethyl ether - TU 6-09-37-1133-91;

- Propylene glycol - TU 6-09-2434-81;

- Ethylene glycol - GOST 19710-83.

A mixture of alcohol, allylethyl ether and an H-Beta catalyst was heated at 80 ° C and stirred vigorously for 5 hours. The molar ratio of alcohol: allylethyl ether = 1.1: 1. At the end of the reaction, the reaction mass is cooled to 20-25 ° C, filtered off from the catalyst and the ethanol liberated is distilled off. After which the reaction mixture is subjected to atmospheric distillation.

Example 1

In a round-bottom flask equipped with a mechanical stirrer, thermometer and reflux condenser, 68.2 g of ethylene glycol, 113 ml of allylethyl ether, 20% wt. (calculated on the reaction mass) of the catalyst H-Beta. With continuous stirring, the reaction mixture was heated at 80 ° C for 5 hours. Then the reaction mass was cooled, the catalyst was separated by filtration, and the ethanol liberated was distilled off. 2-Ethyl-1,3-dioxolanes were isolated by distillation under reduced pressure.

The yield of 2-ethyl-1,3-dioxolane is 95%.

The results of the syntheses are shown in table 1, the syntheses were carried out analogously to example 1. These examples do not exhaust the possibilities of the method in relation to other aliphatic diols and allyl ethers.

The table shows that the proposed method will achieve a yield of substituted 2-ethyl-1,3-dioxolanes of 95% compared to the prototype, where the yield reaches 60%, which will ensure its widespread use as intermediate products of fine organic synthesis, solvents and paint components materials. An additional advantage of the proposed method is the high selectivity of the condensation process - 90% compared with the prototype, where the selectivity is not more than 50%.

Claims (2)

1. A method for producing 2-ethyl-1,3-dioxolanes by condensation of a dihydric aliphatic alcohol with allylethyl ether in the presence of H-Beta zeolite as a catalyst at a temperature of 80 ° C for 5 hours. 2. The method according to p. 1, characterized in that the process with allylethyl ether is carried out in the following ratio of components, wt.%: Alcohol 35-47; allyl ethyl ether 33-45; Zeolite H-Beta 20.