1-Methylpiperazine → Desmethyl Carbodenafil

Participants

Reaction Steps

A solution of 4-ethoxy-3-(1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]-pyrimidin-5-yl)benzoic acid (0.095 g, 0.00027 mol), 1-methylpiperazine (0.265 g, 0.00265 mol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.77 g, 0.0004 mol) and 1-hydroxybenzotriazole (0.054 g, 0.0004 mol) in dichloromethane (25 ) was stirred at room temperature for 18 hours. The reaction solution was washed with water (25 ml), dried (MgSO4) and evaporated under vacuum, and then the resulting residue crystallised from ethyl acetate-hexane to give the title compound as colourless crystals (0.03 g, 25%), m.p. 196°-197° C. Found C,63.12; H,6.81; N,18.96. C23H30N6O3 requires C,62.99; H,6.90; N,19.16%.

Provenance & Evidence