- N-BUTYRAMIDE, THE PREPARATION METHOD AND USE THEREOF
-
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.
- -
-
-
- N-{1-Y3-(2-ETHOXY-5-(4-ETHYLPIPERAZINYL)BENZENESULFONYL)-4,5-DIHYDRO-5-OXO-1,2,4-TRIAZIN-6-YL¨ETHYL}BUTYRAMIDE, THE PREPARATION METHOD AND USE THEREOF
-
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.
- -
-
Page/Page column 9-10
(2010/10/01)
-
- An improved synthetic route for preparative process of vardenafil
-
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).
- Mao, Yongjun,Tian, Guanghui,Liu, Zheng,Shen, Jingshan,Shen, Jingkang
-
experimental part
p. 1206 - 1208
(2010/04/22)
-
- Novel process for the preparation of pyrazolopyrimidinones
-
There is provided a process for the production a compound of general formula I: wherein A, R1, R2, R3 and R4 have meanings given in the description, which process comprises the reaction of a compound of formula II, wherein Rx is a group substitutable by an aminopyrazole, with a compound of general formula III
- -
-
-