Preparation of substituted benzamides

US4575557A · kind A · utility

Assignee

• IMPERIAL CHEMICAL INDUSTRIES LIMITED · GB

Inventors

• John D. Jones · Phoenix, US
• David Schofield · Swinton, GB

Key dates

• Filing date: Jul 30, 1984
• Grant date: Mar 11, 1986
• Expiry date: Jul 30, 2004

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C255/00
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Benzamides of the formula (I): ##STR1## in which Ar is optionally substituted aryl; X is O, S or NH and R is optionally substituted alkyl or alkenyl when X is O or S, or is optionally substituted alkenoyl when X is NH, are prepared by PA0 (a) reacting a compound of the formula (II): EQU ArCONHCH.sub.2 CN (II) PA0 with a brominating agent in a solvent which is substantially chemically inert to the reactants and in which compound (II) is soluble, to form a compound of the formula (III): ##STR2## and (b) reacting the compound (III) with a compound RXH. Preferably, bromination is carried out rapidly in dried ethyl acetate. The process avoids hydration of the CN group of the compound (III) to a carbamoyl group obviating a subsequent dehydration step later. The intermediate compound (III) is novel. The substituted benzamides are useful as herbicides and fungicides.