NEW MATERIAL:Pyrazole derivatives of formula I [X is halogen, alkyl, trifluoromethyl; R1 is methyl, trifluoromethyl; R2 is alkyl, chloromethyl, formula II (Z is halogen; m is 1, 2); Y is oxygen or sulfur atom; n is 1, 2].
EXAMPLE: 4-Acetyl-1(4-chlorophenyl)-5-hydroxy-3-methylpyrazole.
USE: Antimicrobial and herbicidal agent: they show high controlling activity against downy mildew and botrytis cineria in cucumber and rice blast disease as well as high herbicidal activity against broadleaf weeds. They are harmless to crops. They are diluted to an appropriate concentration or directly applied to stalks or leaves of plants, soil or the water surface of rice paddies.
PREPARATION: The reaction of a compound of formula III with another compound of formula IV is carried out in the presence of a base catalyst such as calcium hydroxide in a solvent such as dioxane at a temperature of the boiling one of the solvent to give the hydroxy compound of formula I. The product is made to react with diphosphorus pentasulfide to form the mercapto compound of formula I.
KAWAMOTO AKIRA
HAYASHI SHIGERU
NOZAKI KAZUTOSHI
