51356-13-9 BRN 0811372 Phosphorodithioic acid, O,O-diethyl ester, S-ester with 6-ethyl-2-(mercaptomethyl)-3(2H)-pyridazinone S-6-Ethyl-2-(mercaptomethyl)-3(2H)-pyridazinone O,O-diethyl phosphorodithioate