PRODUCTION OF 2-CHLOROFORMYLETHYLMETHYL-PHOSPHINIC ACID CHLORIDES

摘要

PRODUCTION OF 2-CHLOROFORMYLETHYLMETHYL- PHOSPHINIC ACID CHLORIDES The invention relates to a process for making 2-chloroformylethylmethylphosphinic acid chlorides of the general formula: in which R1 and R2 each stand for hydrogen or CH3. To this end, methyldichlorophosphane is reacted with acrylic acid, methacrylic acid or crotonic acid at elevated temperature. More particularly, a solution of methyldichlorophosphane in phosphorus trichloride, the solution originating from a reaction of phosphorus trichloride with methane at temperatures higher than 500.degree. C, is used. The reaction is effected at temperatures within the range 50 to 90.degree. C in the presence of hydrogen chloride; and the phosphorus trichloride is distilled off.