Preparation of 4-chloropyrazoles

US5047551A · kind A · utility

Assignee

• BASF SE

Inventors

• Ulf Baus · Dossenheim, DE
• Wolfgang Reuther · Neckargemünd, DE

Key dates

• Filing date: Oct 30, 1989
• Grant date: Sep 10, 1991
• Expiry date: Oct 30, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D231/16
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

4-Chloropyrazoles of the general formula I ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are each independently of the others hydrogen or a radical which is inert under the reaction conditions, are prepared by reacting pyrazoles of the general formula II ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are each as defined above, with 0.95-10 equivalents of hypochloric acid, or salts thereof, in the substantial absence of any carboxylic acid.