The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 09, 1991
Filed:
Jun. 29, 1989
Hans R Muller, Schaffhausen, CH;
Martin Ulmann, Dachsen, CH;
Josef Conti, Schaffhausen, CH;
Gunter Murdel, Tengen-Busslingen, DE;
Eprova AG, Schaffhausen, CH;
Abstract
For the preparation of 5,10-methenyl-(6R)-, 5-formyl-(6S)- or 5-methyl-(6S)-tetrahydrofolic acid or salts thereof, 5,10-methenyl-(6R,S)-tetrahydrofolic acid, the inner salt thereof or one of the salts thereof with strong acids is subjected to diastereomer separation by fractional crystallization and, if desired, the resulting 5,10-methenyl-(6R)-tetrahydrofolic acid is converted by treatment with a hydrolyzing agent into 5-formyl-(6S)-tetrahydrofolic acid or by treatment with a reducing agent into 5-methyl-(6S)-tetrahydrofolic acid, and the resulting free acid may be converted into one of its salts by treatment with a base.