NEW MATERIAL:A compound shown by the formula I (R1 is H, or halogen; R2 is halogen; R3 is OH, alkoxy, lower alkenyloxy, lower alkylthio, lower alkylamino, etc.; R4 is lower alkyl, or cycloalkyl).
EXAMPLE: 3-(2,4-Dichloro-5-ethoxycarbonylphenyl)-5-t-butyl-1,3,4-oxadiazolone-2.
USE: A herbicide. Showing improved herbicidal effect on barnyard grasses, broad- leaved weeds, perennial weeds in paddy fields, broad-leaved weeds, etc. in plowed fields with a small amount of it, having low phytotoxicity to crops.
PREPARATION: A compound shown by the formula II is reacted with phosgene or ClCOOCCl3 in an inert solvent such as an aromatic hydrocarbon, aliphatic hydrocarbon, chloroform, ketone, etc. at room temperature W120°C to give a compound shown by the formula I .
YANAGI MIKIO
NITANI FUMIO
SHIDA ATSUHIKO
