Methyl chloroformate → HCID 131723415, compound

Participants

Reaction Steps

Methyl chloroformate (55 mg) was added to a solution of 3-(4-chlorophenyl)-4-(4-pyridyl)-5-(4-piperazinyl)pyrazole (200 mg, 0.54 mmol; prepared as set forth in Example A-169) and 4-dimethylaminopyridine (5 mg) in pyridine (10 mL). The mixture was stirred at room temperature for 3 hours. Additional methyl chloroformate (30 mg) was added and stirring was continued for 24 hours. The solvent was removed in vacuo. The residue was treated with water and extracted with ethyl acetate. After drying the organic layer (MgSO4), the solvent was blown down to a volume of 10 mL and refrigerated. The resultant crystalline solid was filtered and air dried to give 103 mg (48%) of methyl 4-[5-(4-chlorophenyl)-4-(4-pyridinyl)-1H-pyrazol-3-yl]-1-piperazinecarboxylate, monohydrate, mp 264–265° C. Anal. Calc'd. for C20H20ClN5O2.H2O: C, 57.76; H, 5.33; N, 16.84. Found: C, 57.98; H, 4.89; N, 16.44.

Provenance & Evidence