S-phenyl-s-alkyl-o-alkyl-dithiophosphoric acid esters - prepd by reaction of s-phenyl-o-alkyl-thiophosphoric acid chloride with mercap

摘要

Cpds. of general formula (I) Cl-CH2-CRNO2-CH2-O-POSR'SR" where R and R' = alkyl (max. 6C) R" = phenyl opt. mono- or poly-substd. with halogen or alkyl (max 4C); are prepd. by reacting a cpd. (II) Cl-CH2-CRNO2-O-POSR" Cl with a cpd. (III) R'SH in the form of salts or in the presence of acid-binding agents. Reaction is pref. at 20-60 degrees C using excess (III). (I) have strong fungitoxic activity without phytotoxicity for cultures and with low mammalian toxicity. They may be used as plant-protection agents against parasitic moulds attacking plants above- and below the soil level. They are esp. active against Piricularia oryzae showing not only protective but also curative and systemic effects. They may also be used as seed disinfectants or as soil treatment agents against phytopathogenous fungi. (I) have also insecticidal action.