Patent · US Expired

Preparation of pyrazole and its derivatives

US4996327A · kind A · utility

7Cited by

2References

5Claims

0Family size

Assignee

BASF SE

Inventors

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

Key dates

Filing date	Jun 7, 1990
Grant date	Feb 26, 1991
Priority date	—
Expiry date	Jun 7, 2010

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D231/12
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Pyrazole and its derivatives are prepared by dehydrogenating 2-pyrazoline or its derivatives by a process in which the reaction is carried out using sulfuric acid in the presence of iodine or of an iodine compound at from 50.degree. to 250.degree. C.

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