Abstract: | A variety of 1-phenylureas, substituted in the 3-position with one acyl, alkoxycarbonyl or cyano group, and optionally with a lower alkyl group, have been synthesised and assessed for pre- and post-emergence herbicidal activity against a range of monocotyledonous and dicotyledonous weed species. Generally, activity was associated only with compounds containing two small substituents in the 3-position. Their possible metabolic fate is discussed in the light of comparisons with the activity of the commercial herbicides, fenuron, monuron and diuron, and their de-methylated derivatives. |