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:
Sep. 12, 2000
Filed:
Mar. 02, 1999
Applicant:
Inventors:
James M VanderRoest, South Haven, MI (US);
James J Springer, Saugatuck, MI (US);
Richard S Olsen, South Haven, MI (US);
Assignee:
Wyckoff Chemical Company, Inc., South Haven, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
546257 ; 546288 ; 546298 ;
Abstract
The present invention comprises a process for preparing essentially pure 1,2-dihydro-6-alkyl-2-oxo-5-(pyridinyl)-nicotinonitriles from a crude reaction mixture containing the corresponding amide as an impurity. By 'essentially pure' is meant a level of purity acceptable for orally administered pharmaceutical products, usually less than 0.1% of any single impurity. At least a stoichiometric amount of an acylating agent is reacted with the crude reaction mixture, and thereafter recovering essentially pure 1,2-dihydro-6-alkyl-2-oxo 5-(pyridinyl)-nicotinonitrile.