NEW MATERIAL:The hydantoin derivative of formula 1 (R1 is H or galogen; R2 is halogen; R3 is H or 1W8C straight or branched-chain alkyl which may be substituted with lower alkoxy; X is O or S; n is 3 or 4).
EXAMPLE: 3-( 4-Chloro-3-n-propoxycarbonylphenyl )-1,5-trimethylene-2-thiohydantoin.
USE: Herbicide remarkably effective not only to the annual weeds in paddy field, e.g. Deccan grass and broad-leaved weeds, etc., but also to the perennial weeds such as slender spikerush, etc.
PROCESS: The compound of formula 1 can be prepared by (1) reacting the proline or pipecolic acid or its eater of formula 2 (R4 is H or lower alkyl; n is 3 or 4) with the substituted-phenyl isocyanate of formula 3, and (2) heating the resultant compound of formula 4 or cyclizing the compound in the presence of a proper acidic catalyst.
KOBAYASHI SHINICHI
YANAGI MIKIO
YAMADA KURA
SAITOU MIKIO
NITANI FUMIO
