Cyclohexyl isocyanate → 1-{3-[4-(4-Chlorobenzyl)piperazin-1-yl]propyl}-3-cyclohexylurea

Participants

Reaction Steps

A solution of 1-(3-aminopropyl)-4-(4-chlorobenzyl)piperazine (2.0 g; 7.5 mmole) and cyclohexyl isocyanate (1.6 g; 12.8 mmole) in tetrahydrofuran (5 ml) was stirred at room temperature for 30 minutes. The reaction mixture was evaporated under reduced pressure, and the residual oil was dissolved in ethanol (10 ml). The crude product was precipitated as a white solid by the addition of water, collected by filtration and recrystallized twice from cyclohexane to yield 1-{3-[4-(4-chlorobenzyl)piperazin-1-yl]propyl}-3-cyclohexylurea (1.62 g; 56% yield) as a white crystalline solid, m.p. 109°-112° C. This product in methylene chloride (20 ml) was precipitated as the dihydrochloride by the addition of excess anhydrous hydrogen chloride. Recrystallization from water provided the title compound as colorless crystals, m.p. 184°-187° C.

Provenance & Evidence