Herbicidal pyrazolin-5-one derivatives, compositions and use

Abstract

Herbicidal pyrazolin-5-one derivatives of the formula ##STR1## in which R.sup.1 represents alkyl, cycloalkyl, halogenoalkyl, alkenyl, alkynyl, alkenyl or alkynyl substituted by optionally substituted phenyl, halogenoalkenyl, alkoxy, alkoxyalkyl, alkylthioalkyl, alkylsulphonylalkyl, alkylsulphinylalkyl, alkoxycarbonylalkyl, in each case optionally substituted aryl, aralkyl, aryloxyalkyl or arylthioalkyl, an optionally substituted heterocycle, heterocyclylalkyl or the --NH--CO--R.sup.3 or --CO--O--R.sup.4 groups, in which R.sup.3 and R.sup.4 in each case independently of one another represent alkyl or aryl, R.sup.2 represents hydrogen, alkyl, cycloalkyl, halogenoalkyl, alkenyl, alkinyl, halogenoalkenyl, alkoxyalkyl, alkylthioalkyl, alkylsulphonylalkyl, alkylsuslphinylalkyl or alkoxycarbonylalkyl and Ar represents optionally substituted aryl or a heterocycle which is optionally substituted and optionally fused, excluding the compounds 1-(3-chlorophenyl)-3-methylthiomethyl-4-(N-hydroxyaminomethylidene)-pyrazo line-5-one, 1-(4-chlorophenyl)-3-methylthiomethyl-4-(N-hydroxyaminomethylidene)-pyrazo lin-5-one, 1-(4-trifluoronethylphenyl-3-methylthiomethyl-4-(N-hydroxyaminomethylidene ))-pyrazolin-5-one and 1-(4-n-nitrophenyl)-3-methylthiomethyl-4-(N-hydroxyaminomethylidene)-pyraz olin-5-one.

Dependencies are inferred from the claim text.