Reaction #992698

Reaction equation

dimethyldithiophosphoric acid

diethyl maleate

hydroquinone

→

malathion

Conditions

Workup

1. 1
   TemperatureThe two-phase mixture was cooled to 22-30° C.
2. 2
   Otherthe phases were separated
3. 3
   WashThe organic phase was washed with water (2×1 kg)

Procedure

The aqueous solution of dimethyldithiophosphoric acid was combined with diethyl maleate (1.33 kg) and hydroquinone (3.3 g), and the resulting two-phase mixture was heated for 8 h at 53-57° C. under nitrogen atmosphere. The two-phase mixture was cooled to 22-30° C., and the phases were separated. The organic phase was washed with water (2×1 kg) to afford crude malathion (1.86 kg) containing at least about 30% (w/w) diethyl fumarate.

Source