22439-39-0 6-Chloro-2-(mercaptomethyl)-3(2H)-pyridazinone O,O-dimethyl phosphorodithioate BRN 0664377 Phosphorodithioic acid, O,O-dimethyl ester, S-ester with 6-chloro-2-(mercaptomethyl)-3(2H)-pyridazinone