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:
Mar. 11, 2003
Filed:
Apr. 17, 2001
Applicant:
Inventors:
Michael Christopher James Harris, Cambridge, GB;
Hooshang Zavareh, Cambridge, GB;
Assignee:
Chiroscience, Ltd., , GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A61K 3/1445 ; A61K 3/147 ; A61K 3/121 ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
A61K 3/1445 ; A61K 3/147 ; A61K 3/121 ; C07D / ; C07D / ;
Abstract
Single isomer methylphenidate, selected from the d- and l-threo-enantiomers, has been obtained in purified form, to the extent of less than 2% by weight of a contaminant selected from resolving agent and ritalinic acid. This is achieved by resolution of a mixture of enantiomers using an O, O′-diaroyltartaric acid as resolving agent.