Chlorthiophos

Chlorthiophos is an organophosphorus pesticide. It is a mixture of isomers:

O,O-diethyl-O-(2,5-dichloro-4-methylthio)phenyl phosphorothioate (ca. 73%)

O,O-diethyl-O-(4,5-dichloro-2-methylthio)phenyl phosphorothioate (ca. 13%)

O,O-diethyl-O-(2,4-dichloro-5-methylthio)phenyl phosphorothioate (ca. 14%)