Preparation of .alpha.-ketocarboxylic acid N-tert.-butylamides

US4345100A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Bonse · Neunburg vorm Wald, DE
• Heinz U. Blank · Odenthal, DE

Key dates

• Filing date: Jan 2, 1981
• Grant date: Aug 17, 1982
• Expiry date: Jan 2, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D253/075
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of an .alpha.-ketocarboxylic acid N-tert.-butylamide of the formula EQU R--CO--CO--NH--C(CH.sub.3).sub.3 in which PA1 R is an aliphatic radical with up to 8 carbon atoms, a cycloalkyl radical with 3 to 6 carbon atoms, a phenyl or naphthyl radical or a heterocyclic radical, comprising reacting an acyl cyanide of the formula EQU R--CO--CN with tert.-butyl methyl ether of the formula EQU (CH.sub.3).sub.3 C--O--CH.sub.3 at a temperature between about 0.degree. and 80.degree. C. in the presence of an acid which is capable of activating the ether of formula (III) under the reaction conditions to give a tert.-butyl carbonium ion, and then hydrolyzing the reaction mixture. Advantageously the acyl cyanide is pivaloyl cyanide or benzoyl cyanide and is reacted with an approximately equimolar amount of the ether in the presence of about 1.1 to 1.5 times the molar amount of concentrated sulphuric acid as the activating acid. The products are useful as intermediates in the synthesis of known herbicides.