Preparation of 3,5-diarylpyrazoles

US5744614A · kind A · utility

Assignee

• BASF SE

Inventors

• Hans Rupert Merkle · Ludwigshafen, DE
• Erich Fretschner · Neckarsteinach, DE

Key dates

• Filing date: Jul 3, 1997
• Grant date: Apr 28, 1998
• Expiry date: Jul 3, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D231/12
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for preparing 3,5-diarylpyrazoles of the general formula I ##STR1## where the substituents have the following meanings: R.sup.1 and R.sup.3 are unsubstituted or substituted aryl radicals, R.sup.2 is hydrogen, C.sub.1 -C.sub.8 -alkyl or unsubstituted or substituted aryl, PA0 in which hydrazine hydrate is reacted with a 1,3-diarylpropenone of the general formula II ##STR2## where the substituents R.sup.1, R.sup.2 and R.sup.3 have the abovementioned meanings, in sulfuric acid in the presence of iodine or an iodine compound, is described.