Patent · US Expired

Process for the preparation of 2,4-dimethyl-3,5-bisalkoxycarbonylpyrrole

US6258959A · kind A · utility

1Cited by

0References

6Claims

0Family size

Assignee

BASF SE

Inventors

Carsten Groning · Mannheim, DE
Reinhard Kemper · Heidelberg, DE
Markus Frede · Eppelheim, DE
Klaus Ebel · Lampertheim, DE

Key dates

Filing date	Dec 13, 1999
Grant date	Jul 10, 2001
Priority date	—
Expiry date	Dec 13, 2019

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D207/34
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

A process for the preparation of 2,4-dimethyl-3,5-bisalkoxycarbonylpyrrole is described, in which an acetoacetic alkyl ester is nitrosated to give the 2-nitrosoacetoacetic alkyl ester, the nitroso compound is reduced using hydrogen in the presence of a noble metal catalyst to give the amine, and the resulting amino compound is condensed without isolation in the presence of the corresponding non-nitrosated acetoacetic alkyl ester to give the 2,4-dimethyl-3,5-bisalkoxycarbonylpyrrole. The process makes it possible to work under conditions which are milder than in the prior art and to avoid the formation of by-products.

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