1,1'-Carbonyldiimidazole → Pruvanserin

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Reaction Steps

5 g (0.027 mol) of 3-cyanoindole-7-carboxylic acid are dissolved in 40 ml of hot N-methylpyrrolidone, the solution is cooled to 40°, and 7.6 g (0.027 mol) of N,N-carbonyldiimidazole are added. The mixture is stirred at room temperature for a further one hour. A suspension of 1-(2-(4-fluorophenyl)ethyl)piperazine dihydrochloride in 40 ml of N-methylpyrrolidone is subsequently poured in. After 5 minutes, a clear solution is formed and just afterwards white crystals deposit. The mixture is stirred overnight at room temperature. The crystals are filtered off with suction, washed and dried, giving 5 g of 7-{4-[2-(4-fluorophenyl)ethyl]piperazin-1-carbonyl}-1H-indole-3-carbonitrile as the free base having a melting point (m.p.) of 192.0-193.5°.

Provenance & Evidence