Preparation of O,S-dimethyl-thiol-phosphoric acid diester-amide
AssigneeBayer Aktiengesellschaft
InventorWolfgang Hofer
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Abstract
The new compound tetramethyl-dithiolpyrophosphoric acid ester of the formula ##EQU1## is produced by reacting phosgene with an alkali metal or ammonium salt of O,S-dimethylthiolphosphoric acid ester, preferably in a diluent. By-product chloride salt precipitates out and the solvent can be separated from the desired product or the solution can be directly reacted with ammonia to form the insecticidally active O,S-dimethylthiolphosphoric acid diester-amide.
Claims3
A process for the production of O,S-dimethyl-thiol-phosphoric acid diesteramide of the formula ##EQU6## which comprises reacting about 1.3 moles of phosgene with about 2 moles of a salt of O,S-dimethyl-thiolphosphoric acid ester of the formula ##EQU7## in which M is an alkali metal of ammonium,
- at about 20.degree. to 60.degree. C in the presence of a diluent to form tetramethyl-dithiolpyrophosphoric acid ester of the formula ##EQU8## and contacting the tetramethyl-dithiolpyrophosphoric acid ester in an inert diluent with ammonia.
Dependencies are inferred from the claim text.