RU2620268C1 - Method for producing cyclopropilcarbonic acids - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the preparation cyclopropylcarbonic acid derivatives, which are useful as plasticisers and surfactants. The method consists in that the oxidation is carried out in a number of cyclopropane olefin mixture with sodium hydroxide, methanol and methylene chloride, and ozone at -50°C.

EFFECT: increase in output as well as quality of the end product.

2 cl, 1 tbl, 2 ex

Description

The invention relates to organic chemistry, specifically to the production of cyclopropylcarboxylic acids, derivatives of which are used as plasticizers and surfactants.

A known method for producing cyclopropylcarboxylic acids by oxidation of 1,1-dichloro-2-vinyl-2-cyclopropanes with potassium permanganate at a temperature of 0 ° C in the presence of a catamine phase transfer catalyst (Arbuzova T.V. Synthesis of substituted heme.-dichlorocyclopropanes and reactions based on them. / / Diss ... can. Chemical sciences. Ufa. 2006, 111 p.).

The disadvantages of this method are the use of an expensive oxidizing agent (potassium permanganate), as well as the lack of selectivity for cyclopropylcarboxylic acid.

The technical problem, the solution of which is proposed in the present invention, is to eliminate the above disadvantages and to develop a method for producing cyclopropylcarboxylic acids, characterized by an increase in the yield of the target product.

This problem is solved by the fact that a method for producing substituted cyclopropylcarboxylic acids by oxidation of olefins of the cyclopropane series by ozone at a temperature of -50 ° C is proposed.

The process of oxidation of olefins of the cyclopropane series by ozone is carried out at a temperature of -50 ° C in the presence of the following components, wt. %: 1,1-dichloro-2-vinyl-2-cyclopropane 1; sodium hydroxide 1.6; methanol 12.6; methylene chloride 84.8.

The method is as follows.

A solution of 1,1-dichloro-2-vinyl-2-cyclopropane in a mixture of NaOH in methanol and methylene chloride was bubbled at -50 ° C until a blue color appeared. At the end of the reaction, the reaction mixture was purged with argon, acidified with sulfuric acid, water was added and stirred at room temperature for 1 hour. Then, the organic layer was separated, and the aqueous layer was extracted with methylene chloride. The combined organic extracts were dried with Na ₂ SO ₄ . The solvent was evaporated under reduced pressure.

The starting reagents must meet the following requirements:

- Sodium hydroxide - GOST 4328-77;

- Methanol - GOST 2222-95;

- Methylene chloride - GOST 9968-86;

- Sulfuric acid - GOST 2184-77;

- Sodium sulfate - GOST 21458-75.

A mixture of 1,1-dichloro-2-vinyl-2-cyclopropane, sodium hydroxide, methanol and methylene chloride was cooled to -50 ° C and an ozone-oxygen mixture was bubbled through it until a blue color appeared. The molar ratio of olefin: NaOH = 0.01: 0.05. At the end of the reaction, the reaction mass is purged with argon, treatment is carried out according to the procedure, after which the solvent is evaporated under reduced pressure.

Example 1

Ozone is passed into a cooled solution containing 0.01 mol of 1,1-dichloro-2-vinyl-2-cyclopropane in a mixture of 20 ml of 2.5 M NaOH in MeOH and 80 ml of CH ₂ Cl ₂ until a blue color appears. The ozonizer productivity is -40 mmol About ₃ / h. At the end of the reaction, the reaction mixture was purged with argon, acidified with sulfuric acid (20 ml, ρ = 1.84 g / cm ³ ), water (30 ml) was added and stirred at room temperature for 1 hour. Then, the organic layer was separated, and the aqueous layer was extracted with methylene chloride. The combined organic extracts were dried with Na ₂ SO ₄ . The solvent was evaporated under reduced pressure.

The yield of 1,1-dichlorocyclopropyl-2-carboxylic acid is 95%.

The synthesis results are shown in the table, the syntheses were carried out analogously to example 1. These examples do not exhaust the possibilities of the method of obtaining in relation to other substituted cyclopropylcarboxylic acids.

The table shows that the proposed method will achieve a yield of cyclopropylcarboxylic acids of 95% compared with the prototype, where the yield reaches 78%, which will ensure widespread use of acids and their derivatives as plasticizers and surfactants. An additional advantage of the proposed method is the high selectivity of the oxidation process - 90% compared with the prototype, where the selectivity is not more than 60%, as well as the chemical purity of the resulting acid and the absence of by-products.

Claims (2)

1. The method of producing cyclopropylcarboxylic acids by oxidation of olefins of the cyclopropane series in a mixture with sodium hydroxide, methanol and methylene chloride, ozone at a temperature of -50 ° C. 2. The method according to p. 1, characterized in that the ozonation process is carried out in the following ratio of components, wt.%: 1,1-dichloro-2-vinyl-2-cyclopropane 1; sodium hydroxide 1.6; methanol 12.6; methylene chloride 84.8.