Acetone → Sildenafil

Participants

Reaction Conditions

Reaction Steps

In a 3-necked flask, N-methyl piperazine (1.34 g, 13.4 mol) and NaOH (47%, 0.49 g) were mixed at room temperature. 3-(4,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo(4,3-d)pyrimidin-5-yl)-(4-ethoxyphenyl)benzene sulfonyl chloride (5 g, 12.2 mmol) was suspended in acetone (50 ml) and the suspension was added to the mixture of bases to form a reaction mixture. The reaction mixture was stirred for 45 mm, cooled to 0° C., and filtered. The collected precipitate was washed with water twice and dried at 50° C. under 10 mm Hg to yield pure sildenafil in 87% yield.

Provenance & Evidence