CS253435B1

CS253435B1 - Process for preparing 2-chloroacrylic acids

Info

Publication number: CS253435B1
Application number: CS862312A
Authority: CS
Inventors: Daniel Vegh; Jaroslav Kovac; Miloslava Dandarova
Original assignee: Daniel Vegh; Jaroslav Kovac; Miloslava Dandarova
Priority date: 1986-04-01
Filing date: 1986-04-01
Publication date: 1987-11-12
Also published as: CS231286A1

Abstract

Riešenie sa týká spůsobu přípravy 2-chlórakrylových kyselin obecného vzorce Ar—CH=CC1—-COOH kde Ar je fenyl, o-, m-, p-nitrofenyl, 2-nitrofuryl, 2-nitrotienyl, 2-bróinfuryl, 2-brómtienyl, furyl, tienyl. Jeho podstata spočívá v tom, že na aryl alebo heteroacylidénmalónové kyseliny sa působí chlórom v prostředí organických rozpúšťadiel vo vodě alebo ich zmesiach pri teplote 5 až 150 °C.The solution concerns the method of preparation of 2-chloroacrylic acids of the general formula Ar—CH=CC1—-COOH where Ar is phenyl, o-, m-, p-nitrophenyl, 2-nitrofuryl, 2-nitrothienyl, 2-bromofuryl, 2-bromothienyl, furyl, thienyl. Its essence is that aryl or heteroacylidenemalonic acids are treated with chlorine in an environment of organic solvents in water or their mixtures at a temperature of 5 to 150 °C.

Description

253435 (Newman MS: Org. React 5, 426 (1949)].

The principle of the preparation of 2-chloroacrylic acids according to the invention is that the aryl or heteroarylidenemalonic acids are

of formula II

COOH

FROM

Ar — CH = C \ t

COOH (Π) where

The invention relates to a process for the preparation of 2-chloroacrylic acids of the formula I

COOH

FROM

Ar — GH = C

Cl 1 (I) where

Ar is phenyl, o-, m-, p-nitrophenyl 2-nitrofuryl

V-2-nitrile O, W-

Ar is as defined above with chlorine in the environment of organic solvents from the group of halogenated hydrocarbons such as dichloromethane, chloroform, tetrachloromethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, bromoform, organic acids and acetic acid. , propionic, further in sulfur, Ν, Ν-dimethylformamide and in water or in mixtures thereof at a temperature of 5 to 150 ° C.

The reaction proceeds as follows:

COOH 2-bromofuryl

Ar — CH = C + Cl 2 -> \ t

COOH, v 2-bromothienyl S 'furyl

2-chloroacrylic acids are important chemical intermediates for the synthesis of acetylenes, polymers, 2-amino acids, etc. Their preparation is carried out by various mainly halogenation and dehalogenation reactions (Houben-Weyl, Methoden der OrganischenChemie, Band V / 4 , Stuttgart 1960), as a condensation, such as Wittig reaction (Johnson AW Ylid Chemistry, Acad.Press, NY and London / 1966). Darzeno synthesis produces byproducts

COOH

Z -> Ar — CH = C \ t

Cl ... / / + CO 2 HCl ,. wherein Ar is as defined above.

The process is energy-efficient, producing products of high purity and high yields of quantitative practice.

The by-products of the reaction are carbon dioxide and hydrogen chloride, which are in the gaseous state under the given conditions. EXAMPLE 1 25 g of 4-nitrobenzilidene malonic acid were dissolved in 200 ml of acetic acid and added in one portion to 10 g of chlorine in 100 ml of acetic acid. The reaction mixture was heated to reflux for 2 h. After distilling off the solvent, 23 g of 2-chloro-3- (4-nitrophenyl) -acrylic acid was obtained with mp 197-202 ° C. 2-thienylidene malonic acid

Claims

Process for preparing 2-chloroacrylic acids of formula I

COOH

FROM

Ar -, CH = C \

Cl (I) where

Ar is phenyl, o-, m-, p-nitrophenyl, 2-nitrofuryl, 2-nitrophenyl, 2-bromofuryl, 2-bromothienyl, furyl, thienyl, characterized in that to aryl or heteroarylidene malonic acids of formula II

INVENTION

COOH

FROM

Ar — CH = C \

COOH (Π) where

Ar is as defined above and is treated with chlorine in the environment of organic solvents from the group of halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, bromoform, organic acids such as acetic acid, propionic acid, etc. in carbon disulphide, Ν, Ν-dimethylformamide and in water or mixtures thereof at a temperature of 5 to 150 ° C.