946856-58-2Relevant articles and documents
PROCESS FOR THE PREPARATION OF SILDENAFIL AND INTERMEDIATES THEREOF
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Page/Page column 7-8, (2010/03/31)
The present invention discloses a process for preparing sildenafil and its intermediates having the structures outlined below: In particular, the present invention provides a process for preparing the compound of formula (I) and its intermediates, i.e. the compounds of formula (I), (II), (III) and (IV). The compound of formula (I) is obtained from the compound of formula (II); the compound (II) is obtained from the compound of formula (III) and methylpiperazine; the compound (III) is obtained by treating the compound of formula (IV) with chlorosulfonic acid; the compound (IV) is obtained though treating the compound of formula (V) in the presence of at least one selected from POX3, PX3, PX5 and their mixtures in any ratio. The process for preparing the compound of formula (I) according to the present invention reduces the side reactions in the processes of the prior art. These improvements lead to higher yields and a better industrial applicability with easier controlling of the reaction.
Synthesis, spectral studies and biological activity of novel 3H-1,5-benzodiazepine derivatives
Kumar, Rajesh,Joshi
, p. 2021 - 2025 (2008/09/18)
Chlorination of 5-(2-ethoxyphenyl)-1-methyl-3-propyl-1, 6-dihydro-7H-pyrazolo [4, 3-d] pyrimidin-7-one 1 with POCl3 affords 5-(2-ethoxyphenyl)-1-methyl-7-chloro-1H-pyrazolo [4, 3-d] pyrimidine 2. Further compound 2 is condensed with different β-diketones / β-ketoesters3a-e, to obtain new β-diketones/β-ketoesters 4a-e. The synthesized new β-diketones/β-ketoesters (4a-e) and o-phenylenediamine (o-PDA) gives biologically active 3H-1,5-benzodiazepines 5a-e. All the newly synthesized compounds are characterized by elemental analysis and spectral studies. The compounds 5a-e have been screened for antimicrobial, antifungal and anthelmintic activity.