Patent · US Expired

Preparation of 3-methylpyrazole

US5128480A · kind A · utility

4Cited by

4References

4Claims

0Family size

Assignee

BASF SE

Inventors

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

Key dates

Filing date	Aug 15, 1991
Grant date	Jul 7, 1992
Priority date	—
Expiry date	Aug 15, 2011

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D249/08
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

3-Methylpyrazole and its derivatives are prepared by reacting butenediols or ethynylalkylcarbinols or their acylates in 30-100% by weight sulfuric acid with unsubstituted or substituted hydrazine or its salts in the presence of catalytic amounts of iodine or an iodine compound.

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