Cyanomethyl acid halides of phosphorus and process for their preparation

Abstract

The invention relates to compounds of the general formula ##STR1## in which R.sup.1 represents Hal or C.sub.1 -C.sub.3 -alkyl and Hal reprsents a halogen having an atomic weight of 35 to 80. The invention also relates to a process for the preparation of such compounds by reacting a compound of the general formula II ##STR2## in which R.sup.2 represents C.sub.1 -C.sub.3 -alkyl or OR.sup.3 and R.sup.3 represents C.sub.1 -C.sub.8 -alkyl, preferably C.sub.1 -C.sub.3 alkyl, with an acid chloride of the formula MHaL.sub.2 (III), in which M represents SO, CO or PHal.sub.3 and Hal represents a halogen having an atomic weight from 35 to 80, and in which the reaction, if M is Co, is carried out in the presence of a catalyst which is customary for the phosgenation of diesters of phosphonic acid. Finally the invention relates to alkyl esters of cyanomethyl-methylphosphinic acid, i.e. to products of the formula II in which R.sup.2 is a methyl group and R.sup.3 is an alkyl group of 1 to 6 carbon atoms.

Dependencies are inferred from the claim text.