Patent · US Expired

Method of preparing alkaline earth metal salts of 2-pyrrolidone-5-carboxylic acid

US4921971A · kind A · utility

5Cited by

2References

5Claims

0Family size

Assignee

Dequssa AG · DE

Inventors

Hans-Peter Krimmer · Burgkirchen an der Alz, DE
Karlheinz Drauz · Alzenau, DE
Silvia Werner · Alzenau, DE

Key dates

Filing date	Oct 17, 1988
Grant date	May 1, 1990
Priority date	—
Expiry date	Oct 17, 2008

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D207/28
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Alkaline earth metal salts of 2-pyrrolidone-5-carboxylic acid (pyroglutamic acid) are prepared by heating the corresponding alkaline earth metal salt of glutaminic acid in the solid state to a temperature in a range of 120.degree. C. to 250.degree. C. until the water liberated by the intramolecular condensation (cyclocondensation) has been completely eliminated.

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