Dimethyl dithiophosphoric acid

Dimethyl dithiophosphoric acid is the organophosphorus compound with the formula (CH3O)2PS2H. It is the processor for production of the organothiophosphate insecticide Malathion. Although samples can appear dark, the compound is a colorless, distillable liquid.

It is prepared by treating phosphorus pentasulfide with methanol:
 * P2S5 +  4 CH3OH    →  2 (CH3O)2PS2H  +  H2S