SYNTHESIS OF O, O'-DIALKYL-O"-(SUBSTITUTED PHENYLGLYOXYLONITRILE OXIMINO)PHOSPHATES AND THIOPHOSPHATES AND THEIR SYNERGISTIC ACTION WITH NICLOSAMIDE AS MOLLUSCICIDE

Twenty compounds of O,O' -dialkyl-O-(substituted phenylglyoxylonitrileoximino) phosphates and thiophosphates were prepared.The screening tests showed that compoundsV4,7,12,18 combined with niclosamide exhibited significant molluscicidal synergism against snails(Oncomelania hupensis hupensis).The LC50 of niclosamide alone and V12 combined with niclosamide(1:1)against snail was 0. 0820 mg·L-1 and 0.0215 mg·L-1,respectively. The molluscicidalactivity of the latter was 3.81 times that of niclosamide alone.The compounds V2,7, 10,13 appeared tohave high molluscicidal activity.