Herbicidal sulfonamides of the formula: ##STR1## and salts thereof, where: A represents a substituted or unsubstituted benzene ring, or a 5- or 6-membered substituted or unsubstituted heteroaromatic ring; Q is --O--, --S-- or a group --CXX'--; X and X', which may be the same or different, are each hydrogen, halogen, cyano, an optionally-substituted alkyl group, or a group --OR.sup.a, --SR.sup.a, or --COR.sup.b ; or one of X and X' represents hydroxy and the other is as defined above; or X and X' together represent .dbd.O or .dbd.S; R.sup.a is an optionally-substituted alkyl, aryl or acyl group; R.sup.b is an optionally-substituted alkyl or aryl group, or a group --OR.sup.c or --NR.sup.c R.sup.d ; R.sup.c and R.sup.d, which may be the same or different, are each hydrogen, or an optionally-substituted alkyl or aryl group; Y is nitrogen or a group CR.sup.9 ; R.sup.1 is an optionally-substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, benzoheterocyclyl or amino group; R.sup.2 is hydrogen, an optionally-substituted alkyl or carboxylic acyl group, or a group --SO.sub.2 R.sup.1 ; R.sup.3 and R.sup.4, which may be the same or different, are each hydrogen, halo, an optionally substituted alkyl, alkoxy, cycloalkyl or amino group, or an optionally-substituted heterocyclyl group; and R.sup.9 represents hydrogen or an optionally-substituted alkyl group.
Novel difluoromethanesulfonamide derivatives of the formula (I) Difluoromethanesulfonamide derivatives represented by the formula wherein X represents halogen, Y represents CH or N, R.sup.1 represents hydrogen, and R.sup.2 represents hydrogen or hydroxy, or R.sup.1 and R.sup.2 together may form C & equals; O with the carbon atom to which they are bonded, and their use as herbicide for paddy field weeds. ##STR00001##
