| 摘要 |
<p>1,187,316. Dehydrohalogenation process. BORG-WARNER CORP. 20 June, 1968 [21 July, 1967], No. 29569/68. Heading C2C.α-Haloacrylic acid derivatives of the formula wherein R is a hydrogen atom or a C 1-10 alkyl, C 6-10 aryl, alkaryl or aralkyl group, X is chlorine or bromine and Y is a cyano group or a carboxylic group of the formula -CO-OR<SP>1</SP>, R<SP>1</SP> being a hydrogen atom or C 1-10 alkyl, C 6-10 aryl, alkaryl or aralkyl group, are obtained by the dehydrohalogenation of the correspondingα,#- dihalopropionic acid derivatives of the formula using alkali-metal monohydrogen phosphates as catalysts, the process being effected by heating an aqueous mixture of the propionic acid derivative and of the alkali-metal hydrogen phosphate to produce an aqueous solution containing the haloacrylic compound, the alkalimetal dihydrogen phosphate and the alkalimetal halide, and regenerating the catalyst by adding an alkaline solution to the aqueous solution obtained after recovery of the haloacrylic compound. The reaction may be carried out in the presence of an antioxidant, a polymerization inhibitor and an antifoam agent. Batch, semicontinuous and continuous methods of operation are illustrated.</p> |
