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:
Jun. 12, 2001
Filed:
Jun. 05, 2000
Applicant:
Inventors:
Akio Imai, Ibaraki, JP;
Toshiyuki Ichinohe, Ibaraki, JP;
Takashi Endo, Ibaraki, JP;
Tomio Tsurugi, Ibaraki, JP;
Makoto Uemura, Ibaraki, JP;
Assignee:
Eisai Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
C07D / ;
Abstract
The present invention provides novel polymorphic crystals (A) to (C) having excellent handling properties and an extremely low content of residual solvent of donepezil used as a precursor for production of donepezil hydrochloride having an excellent action as a medicament, and an industrial process for producing the same. Further, the novel polymorphic crystals (A) to (C) according to the present invention are characterized by the powder X-ray diffraction pattern and/or IR absorption peaks of donepezil represented by the following formula: