Process for preparing O,O-dimethyldithiophosphoric acid and alkaline salts thereof

摘要

Colorless O,O-dimethyldithiophosphoric acid is produced by reaction between a phosphorus sulfide, in particular P4 S7 or P4S10, and methanol, at temperatures of 60 DEG -75 DEG C, with short reaction times, and using toluene as diluent. Colorless alkaline salts of the acid are obtained by neutralizing the toluene solution of the acid at a temperature higher than 30 DEG C and at a pH maintained at 2 to 6.