383427-93-8Relevant articles and documents
N-BUTYRAMIDE, THE PREPARATION METHOD AND USE THEREOF
-
, (2011/08/08)
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), 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.
An improved synthetic route for preparative process of vardenafil
Mao, Yongjun,Tian, Guanghui,Liu, Zheng,Shen, Jingshan,Shen, Jingkang
experimental part, p. 1206 - 1208 (2010/04/22)
A new, convergent synthetic route for the process optimization of vardenafil (Levitra), a potent and effective PDE5 inhibitor, is described. Key improved steps in the preparative process are that the chlorosulfonation reaction is at the beginning and the dehydration-cyclisation reaction is at a later stage so that the synthetic route has a better overall yield and simpler workup operations. The yield of vardenafil produced from this synthetic route is around 45% over seven steps with purity at 99.2% (HPLC).