N-Heteroaryl-N'(pyrid-2-yl-sulphonyl)ureas, their preparation, and their use as herbicides and plant growth regulators

摘要

Pyridylsulphonylureas of the formula (I) and their salts <IMAGE> in which R<1>, R<2>, R<3>, R<4>, A and n are as defined in Claim 1 are suitable for the selective control of harmful plants or for regulating the growth in crops of useful plants. The compounds (I) can be prepared analogously to known processes (see Claim 4) via intermediates, some of which are new, of the formulae benzenesulphonamides (II), carbamates (IV) or sulphonylisocyanates (VI) by reaction with carbamates (III) or with amines (V), the formulae (II) - (VI) being as defined in Claim 4.