Patent · US Expired

Method of producing-coarse crystalline nicotinic acid with a high degree of purity

US4959478A · kind A · utility

7Cited by

1References

7Claims

0Family size

Assignee

Degussa AG · DE

Inventors

Alexander Moller · Gelnhausen, DE
Heinz Friedrich · Hanau, DE
Herbert Kuhn · Prüm, DE
Kurt Winkler · Anchorage, US

Key dates

Filing date	Feb 28, 1989
Grant date	Sep 25, 1990
Priority date	—
Expiry date	Feb 28, 2009

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D213/80
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The invention is directed to a method of producing coarse-crystalline nicotinic acid with a high degree of purity in which 3-cyanopyridine is saponified with aqueous alkali hydroxide and the nicotinic acid is allowed to crystallize out of the alkali nicotinate solution obtained in this manner under the addition of mineral acid at temperatures between 99.degree. and 135.degree. C. The pH is kept above 3.7.

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