| 摘要 |
NEW MATERIAL:A compound of formulaI[R1 is >=2C lower alkyl; R2 and R3 are H, alkyl, (phenyl)alkenyl; alkynyl, alkylthio, phenylthio or (substituted)aralkyl; however, are not H at the same time; R4 is H or methyl; X is halogen; n is an integer 0-2]. EXAMPLE:O,O,alpha-Triisopropyl beta-phenethylphosphonate. USE:A selective herbicide, having powerful weeding action on a wide range of weeds by the foliar treatment after the germination with very low phytotoxicity to important crops, e.g. cotton, soybenas, rice plants, etc., and particularly exhibiting improved selectivity for cotton by the foliar treatment. PROCESS:A beta-phenethylphosphonic ester of formula II is reacted with a halide of the formula R5Y[R5 is alkyl, alkynyl or (substituted)aralkyl; Y is halogen]in the presence of a base to give the compound of formulaI(R2 and R3 are R5; or R2 is R5 and R3 is H). |
