| 摘要 |
4-Benzoyl-5-hydroxypyrazole derivs. (I; R1 = lower alkyl, lower alkenyl, lower alkoxy carbonylmethyl; R2 = lower alkyl; X = halogen atom, nitro group; n = 1,2,3), useful as herbicide, were prepd. by reaction of 5-hydroxy pyrazole derivs. (II) and benzamidine derivs. (III) followed by hydrolysis. Thus, 1,3-dimethyl-4-(2,4-dichlorobenzimidoyl)-5-hydroxypyrazole 5g and 5 % NaOH aq. soln. 100 ml was refluxed for 3 hrs, neutralized with 6N HC1, and extracted with benzene to give title compd. 4.2 g. (m.p. 161-163≦̸C).
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