Preparation of substituted vinylcyclopropane-carboxylic acid esters

US4256907A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Klaus Naumann
• Rudiger Schubart · Wittlich, DE
• Thomas Schmidt · Neustadt, DE

Key dates

• Filing date: Apr 24, 1978
• Grant date: Mar 17, 1981
• Expiry date: Apr 24, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of a substituted vinyl-cyclopropanecarboxylic acid ester of the formula ##STR1## in which R.sup.1 and R.sup.2 each independently is alkyl with 1-4 carbon atoms or halogen, PA0 R.sup.3 is halogen, phenoxy or phenoxy substituted by alkyl with 1-4 carbon atoms or by halogen, PA0 R.sup.4 is halogen or methyl, and PA0 n is 0, 1, 2, 3 or 4, comprising saponifying with alkali an ester of the formula ##STR2## in which R.sup.5 is alkyl with 1-4 carbon atoms, thereby to replace R.sup.5 by an alkaline salt group, and directly reacting such salt without intermediate purification with a benzyl chloride of the formula ##STR3## Advantageously the benzyl chloride is obtained by the gas-phase photochlorination of a compound of the formula ##STR4## the chlorination proceeding to about 25 to 75%, and the chlorination mass being employed directly without isolation.