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:
Jan. 20, 2009
Filed:
Apr. 25, 2005
Akio Imai, Ibaraki, JP;
Akihiko Shimotani, Ibaraki, JP;
Akio Imai, Ibaraki, JP;
Akihiko Shimotani, Ibaraki, JP;
Eisai R&D Management Co., Ltd., Bunkyo-ku, JP;
Abstract
The present invention provides a simple method of producing polymorphic crystal (III), which has high safety to environment and the bodies of operators; is gentle to environment; and can produce at low costs; and has a high refining effect. It is a method of producing polymorphic crystal (III) of donepezil hydrochloride (chemical name: 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine•monohydrochloride) represented by the following structural formula (formula (I)), which comprises dissolving donepezil (chemical name: 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine) in ethanol; and adding hydrochloric acid or hydrogen chloride thereto, followed by stirring.