4-Oxy-phenoxy-alkane carboxylic acid derivs. - are herbicides effective against grasses e.g. avena and echinochloa without harming crops e.g. cereals

摘要

4-Oxyphenoxyalkane carboxylic acid derivs. of formula (I) are new: (where R is halogen, CF3, NO2, CN, 1-4C alkyl or 1-4C alkoxy; X is O, S, NH or N-(1-4C)alkyl, Z is -CO-OR1, -CO-SR2, -CO-NR3R4, -CO-NR5-NR6R7, -CS-NH2, -CN, -CH2OH, -CH2-O-CO-R8, -CH2-O-CO-NR3R4 or -CH2-O-SO2-R9; n is 0-2; R1 is H or 1-12C alkyl, opt. substd. by halogen, alkoxy, alkylthio, alkylamino, Ph, CN, alkoxycarbonyl or PhO, opt. substd. 5-6C cycloalkyl, 3-6C alkenyl, opt. substd. 3-4C alkynyl, furfuryl, tetrahydrofurfuryl or a cation equiv. of a base; R2 is 1-6C alkyl, opt. substd. phenyl-(1-2C)-alkyl 3-6C alkenyl or opt. substd. Ph. R3 and R4 are each H, 1-6C alkyl, hydroxy-(1-6C)-alkyl, 5-6C-cycloalkyl, or opt. substd. Ph, provided that R4 and R5 are not both Ph, or R4 and R5 together form a 2,4- or 5-membered methylene chain, in which one CH2 gp. can be replaced by O, NH or NMe; R5 is H or Me; R6 is H, Me or Et; R7 is H, Me, Et or Ph; R8 is opt. substd. 1-6C alkyl, cyclopropyl, 3-6C alkenyl, Ph, 1-4C alkyl-phenyl, 1-4C alkoxyphenyl, halophenyl, trifluoromethylphenyl or nitrophenyl; R9 is 1-4C alkyl or opt. substd. Ph. (I) are herbicides, effective against a wide variety of annular and perennial grasses, but are well tolerated by dicotyledonous plants and some cereals.