SU1549946A1 - Method of obtaining dialkyl ethers of 2-2,2-dichlorvinyl malonic acid - Google Patents

Abstract

The invention relates to derivatives of dicarboxylic acids, in particular the preparation of dimethyl (ethyl) ovine esters of 2- (2,2-dichlorovinyl) malonic acid - intermediates in organic synthesis. The goal is to increase the yield of target substances and simplify the process. The latter is carried out by the dehydrochlorination of dimethyl (ethyl) ovate 2- (2,2,2-trichloroethylidene) malonic acid under the action of zinc in a ratio of 1: (1-3) in ether and / or ethyl acetate, or tetrahydrofuran. These conditions increase the yield of the desired substances to 70-90% of the available starting materials.

Description

(L

with

The invention relates to organic chemistry, specifically to a method for producing dialkyl esters of 2- (2,2-dichlorovinyl) malonic acid of the general formula

CC17 CH-CH (COOI) g,

where R is methyl, ethyl.

The aim of the invention is to simplify the process and increase the yield of the target product.

Chromimer 1. Dimethyl ester of 2- (2,2-dichlorovinyl) malonic acid.

958 g of CO, 15 mol of zinc in the form of fine chips, 20 ml of ether and 15 ml of ethyl acetate are introduced into the reaction flask equipped with a stirrer, reflux condenser, addition funnel and thermometer. Then, 13.1 g (0.05 mol) of 2- (2,2,2-trichloroethylidene) malonic acid dimethyl ester are added dropwise and occasionally with stirring 1 to 10 ml of ether. The reaction mixture is heated until the start of the reaction, after which it proceeds spontaneously at the boiling point of the reaction mixture (42-47 ° C). After completion of the addition, the reaction mixture is heated for 15 minutes at 45-50 ° C, cooled, 30 ml of ether is added, hydrolyzed with 10% HC1, washed with water, the organic layer is separated, dried with anhydrous sodium sulfate, the solvents are distilled off and the product is purified by distillation in a vacuum. Yield 10 g (88%). T. Kip.

 1.3333,

ate

СОъ WITH CO 4b

Uh

100-10GS / 3 mm Hg; d2о

  1.4719.

Found%: C1 31.04.

C-jHgO Cl-ji.

Calculated,%: C1 31.14.

IR spectrum,,): 1735-1750 (C 0), 1625 (C C). PMR, P, ppm,

in CCl: d. 6.18 J 9, Hz (CH), d. 4.39 J 9.4 Hz (CH), p. 3.79 (OCH3).

Example 2. 2- (2-, 2-di chloro vinyl) malonic acid diethyl ester

In a reaction flask equipped with a stirrer, reflux condenser, addition funnel and thermometer, 6.5 g (0.1 mol) of zinc in the form of fine chips, 10 ml of ether and 20 ml of ethyl acetate are added. Then, 14.5 g (0.05 mol) of diethyl ether (2-g (2,2,2-trichloroethylidene) malonic acid in 10 ml of ether) are added dropwise and with stirring to the reaction. after which the reaction proceeds spontaneously at the boiling point of the solvent 46-51 ° C. After the end of the addition, the mixture is heated for 15 minutes at 50 ° C and treated as in Example 1. Output 11.5 (30%) .T.kip. 112 -113 ° C / 3 mmHg, 1.2357, p 1.4618. C1 27.92.

Found,%. CjH, Calculated, IR spectrum,

S: C1 27.81. L cm 1: 1735-174 (C 0), 1625 (OS). PMR, SR, ppm, CC14): d. 6.18, J 9.4 Hz (СН), D. 4.30 J 9.4 Hz (СН), r. 4.20, J 7 Hz (CH4), t. 1.30 J 7 Hz (CH3).

PR and MU e p 3. Diethyl ether 2- (2,2-dichlorovinyl) malonic acid

To the reaction flask, equipped with a stirrer, reflux condenser, addition funnel and thermometer, 3.25 g (0.05 mol) of zinc are added in the form of fine chips, 10 ml of ether and 20 ml of ethyl acetate. Then, 14.5 g (0.05 mol) of 2- (2,2,2-trichloroethylidene) malonic acid diethyl ether in 10 ml of ether are added dropwise and with stirring. The reaction mixture is heated until the reaction begins, after which the reaction proceeds spontaneously at the boiling point of the solvents. After completion of the addition, the mixture is heated for 45 minutes at 50 ° C and treated as in Example 1. Yield 11.4 g

(89S).

Example 4 (solvent - ether). 6.5 g (0.1 mol) of finely ground zinc, 30 ml of ether and 0.5 ml of chloral are introduced into the reaction flask. The reaction mass is heated to boiling, and then 14.5 g are added dropwise thereto and with stirring.

Q

five

five

(0.05 mol) of 2- (2,2,2-trichloroethylidene) malonic acid diethyl ether in 10 ml of ether. Further operations are carried out as in Example 2. T. kip. reaction. Yield 11.1 g (871).

Example 5 (solvent - ethyl acetate). 6.5 g (0.1 mol) of zinc in the form of fine chips, 30 ml of ethyl acetate are introduced into the reaction flask. The remaining operations as in example 2. T. Kip. reaction 77 ° C. Yield 8.9 g (70S;).

Example 6 (solvent is hexane). 6.5 g (0.1 mol) of zinc in the form of fine chips, 30 ml of hexane and 0.5 ml of chloral are introduced into the reaction flask. The reaction mass is heated to boiling and 14.5 g (0.05 mol) of 2- (2,2,2-trichloroethylidene) malonic acid diethyl ether are added dropwise thereto while stirring. The mixture was heated for 2 hours at 70 ° C and treated as in Example 1. The reaction did not proceed; the initial diethyl ester 2 (2,2,2-trichloroethylidene) malonic acid was isolated.

Example 7 (solvent - benzene). 6.5 g (0.1 mol) of zinc, 30 ml of benzene and 0.5 ml of chloral are introduced into the reaction flask. The remaining operations as in Example 6. The reaction does not proceed, the initial 2- (2,2,2-trichloroethylidene) malonic acid diethyl ester is isolated.

Example 8 (solvent is tetrahydrofuran). 6.5 g (0.1 mol) of zinc, 30 ml of THF and 0.5 ml of chloral are introduced into the reaction flask. The remaining operations as in example 6, Yield 9.6 g (76%).

Example 9 (1: 3 ratio of chlorine derivative and zinc). 9.8 g (0.15 mol) of zinc, 20 ml of ether, 15 ml of ethyl acetate and 14.5 g (0.05 mol) of 2- (2,2,2-trichloroethylidene) malonic acid diethyl ether are introduced into the reaction flask. in 10 ml of ether. The remaining operations as in example 1. Output 11.6 g 0 (91%).

2- (2,2-dichlorovinyl) malonic acid dimethyl ester.

Example 10. The ratio of chlorine derivative and zinc is 1: 2. Conditions 5 are carried out as in example 2. Yield 9.7 g (87%).

Example 11, The ratio of chlorine derivative and zinc 1: 1. Condition pro0

five

0

five

Conducting the reaction as in Example 3. Yield 9.5 g (85%).

Example 12. The ratio of chlorine derivative and zinc is 1: 2, the solvent is ether. Zinc was preactivated with chloral and washed with ether, so no chloral was added to the reaction flask. The remaining operations are carried out as in the example. Yield 9.7 g (87%).

Example 13, The ratio of chlorine derivative and zinc is 1: 2, the solvent is ethyl acetate. The conditions were as in Example 5. Yield: 8.2 g (73%).

Example 1. The ratio of chlorine derivative and zinc is 1: 2, the solvent is tetrahydrofuran. Zinc was preactivated with 2% hydrochloric acid, washed and dried, so no chloral was added to the reaction flask. The remaining operations are carried out with a mixture or tetrahydrofuran.

Yu

15

2 analogously to example 8. Output 9.0 g (80%).

The proposed method allows to increase the yield of the target product (70-. 90%) with the simplicity of the synthesis and the availability of initial reagents.

Claims (1)

The invention The method of producing 2 (2,2-dichlorovinyl) malonic acid dialkyl esters of the general formula CC12 CH-CH (COOR) 1, where R is methyl, ethyl, characterized in that, in order to simplify the process and increase the yield, 2- (2,2,2-trichloroethylidene) malonic acid dialkyl ester is reacted with zinc in the ratio of 1: (1-3), respectively, in the medium of ether or ethyl acetate or