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 (100 g, 0.24 mol) was mixed with acetone (1000 ml) at room temperature and NaOH (9.74 g, 47%). N-methyl piperazine (26.8 g, 0.27 mol) was added dropwise. 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 85% yield.

Provenance & Evidence