Acetone → Sildenafil

Participants

Reaction Conditions

Reaction Steps

In a 3-necked flask, 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 mixed with acetone (100 ml) at room temperature, then aqueous NaOH 47% (0.487 g, 10 mmol) was added. N-methyl piperazine (1.34 g, 11 mmol) was added dropwise. The reaction mixture was stirred for 45 mm, then cooled to 0° C. and filtered. The precipitate was washed with water twice and dried at 50° C. under 10 mm Hg to give sildenafil in a 88.8% yield.

Provenance & Evidence