841-77-0

110-85-0

776-74-9

841-77-0

General procedure for the synthesis of N-diphenylmethylpiperazine from piperazine and diphenylmethyl bromide: accurately weigh diphenylmethyl bromide (10 g, 41 mmol), piperazine (9 g, 105 mmol), potassium carbonate (K2CO3, 14 g, 101 mmol) and sodium iodide (NaI). Piperazine (6 g, 40 mmol) was dissolved in toluene (85 mL) and stirred until completely dissolved. The reaction mixture was placed in an oil bath at 110°C and refluxed for 4 hours. The progress of the reaction was monitored by thin layer chromatography (TLC) during the reaction. After completion of the reaction, it was cooled to room temperature and dichloromethane (DCM) was added to disperse the reaction mixture. The insoluble material was removed by filtration and the filtrate was collected. The filtrate was concentrated and purified by silica gel column chromatography using an elution system containing 1% triethylamine in a gradient elution with petroleum ether and ethyl acetate (ratio tapered from 1:2 to 1:3). The target compound N-diphenylmethylpiperazine (S8, 7.6 g) was finally obtained in 74.2% yield.