Patent · US Expired

Method for producing 1 substituted 5-chloro-4 methly pyrazoles

US7002023B2 · kind B2 · utility

0Cited by

2References

11Claims

0Family size

Assignee

BASF SE

Inventors

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

Key dates

Filing date	Sep 28, 2001
Grant date	Feb 21, 2006
Priority date	—
Expiry date	Oct 1, 2021

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D231/22
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The present invention relates to a process for preparing 1-substituted 5-chloro-4-methylpyrazoles of the general formula I with the meaning for R stated in claim 1, in which a 4-methylpyrazole of the formula II is reacted with chlorine, the resulting mixture of monochlorinated and dichlorinated product is fractionated by distillation, and subsequently the dichlorinated compound is dehalogenated to compound II and returned to the reaction with chlorine.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.