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. 02, 2013
Filed:
Dec. 28, 2007
Guanghui Tian, Shanghai, CN;
Zheng Liu, Shanghai, CN;
Jin Zheng, Shanghai, CN;
Jingshan Shen, Shanghai, CN;
Guanghui Tian, Shanghai, CN;
Zheng Liu, Shanghai, CN;
Jin Zheng, Shanghai, CN;
Jingshan Shen, Shanghai, CN;
Topharman Shanghai Co., Ltd., Shanghai, CN;
Abstract
Disclosed are N-{1-[3-(2-ethoxy-5-(4-ethylpiperazinyl)sulfonylphenyl)-4,5-dihydro-5-oxo-1,2,4-triazin-6-yl]ethyl}butyramide (which is represented by formula III and utilized for preparing vardenafil), its preparation method, intermediates during preparation procedure, preparation method for such intermediates and a method for preparing vardenafil from the compound. In the method for preparing vardenafil, a chloro-sulfonation reaction carries out in the early stage of the preparation procedure