1-Phenylpiperazine → 3,4-Dihydro-2-methyl-4-[2-(4-phenyl-1-piperazinyl)ethyl]pyrimido[1,6-a]benzimidazol-1(2H)-one

Participants

Reaction Steps

To 4.0 g (0.015 mol) of 4-(2-chloroethyl)-3,4-dihydro-2-methylpyrimido[1,6-a]benzimidazol-1(2H)-one in 35 mL of toluene was added 6.5 g (0.04 mol) of N-phenylpiperazine. The reaction mixture was heated to reflux for 2 days. The entire reaction mixture was washed with 3×50 mL of 1N NaOH, dried over Na2SO4, filtered, and concentrated by rotary evaporation. The residue was subjected to preparative HPLC using acetone as the eluent and silica gel as the stationary phase. Like fractions were combined, concentrated and the residue crystallized from isopropyl alcohol to give 3.7 g (64%) of analytically pure, crystalline material, mp 143.5°-145.5° C.

Provenance & Evidence