Sodium Bicarbonate → 2-{1-[4-(6-Phenyl-imidazo[1,2-a]pyrimidin-7-yl)-benzyl]-piperidine-4-yl}-quinoxaline

Participants

Reaction Steps

195 mg (0.6 mmol) 2-Piperidine-4-ylquinoxaline are dissolved in 4.9 mL NMP. After addition of 0.19 mL triethylamine the reaction mixture is stirred for one hour. 170 mg (0.57 mmol) 4-(6-Phenyl-imidazo[1,2-a]pyrimidin-7-yl)-benzaldehyde (intermediate example 1.0) and 0.06 mL acetic acid are added. The reaction mixture is stirred overnight at room temperature. 132 mg (0.63 mmol) NaBH(OAc)3, are added in portions and the reaction mixture is stirred at room temperature for 18 hours. Additionally 75 mg NaBH(OAc)3 and 0.03 mL acetic acid are added and the stirring is continued for 23 hours. The reaction mixture is treated with saturated NaHCO3 and stirred vigorously for one hour. The precipitate is filtered off, washed with water and dried. After chromatography of the precipitate on silica gel (dichloromethane/methanol) 127.4 mg (45.2%) of the pure product are obtained. Another 66.1 mg (23.4%) of slightly contaminated product are obtained.

Provenance & Evidence