960009-36-3Relevant academic research and scientific papers
Synthesis of Sildenafil citrate and process related impurities
Kumar, Indukuri V.S.,Ramanjaneyulu, Gorantla S.,Bindu, Vurimindi H.
, p. 668 - 673 (2011)
Synthesis of Sildenafil by the O-alkylation of 5-[2-hydroxy-5-(4- methylpiperazin-1-ylsulphonyl)phenyl]-1-methyl-3-n-propyl-1,6-dihydro-7H- pyrazolo-[4,3-d]pyrimidin-7-one 8 proved difficult because concomitant alkylation of the pyrimidine moity also occurred. The selective O-alkylation was carried by DCC assisted decarboxilative etherification of the carbonate 9.
NOVEL PROCESS FOR THE PREPARATION OF SILDENAFIL CITRATE
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Page/Page column 5; 12, (2008/06/13)
Disclosed herein the process for producing 5-[2-ethoxy-5-(4-methyl)piperazine-l-yl- sulfonyl)phenyl]- 1 -methyl-3-n-propyl- 1 ,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one or its salt thereof employing novel intermediate.
