107-04-0

57260-71-6

208167-83-3

General procedure for the synthesis of 1-BOC-4-(2-chloroethyl)piperazine from 1-bromo-2-chloroethane and N-BOC-piperazine: firstly, di-tert-butyl dicarbonate (18.98g, 87.07mmol) was added slowly and dropwise to the suspension of dipiperazine (30.00g, 348.27mmol) and sodium carbonate (106g, 348.27mmol) in dichloromethane (200ml) 87.07 mmol) in dichloromethane solution (30 ml), the titration process lasted for 1 hour and the reaction was carried out at room temperature. After completion of the dropwise addition, the reaction mixture was stirred at room temperature overnight. At the end of the reaction, the mixture was mixed with water (100 ml) and the organic phase was separated. The organic layer was dried with magnesium sulfate followed by evaporation under reduced pressure to remove the solvent. The residue was dissolved in dichloromethane (150 ml) and sodium carbonate (15.55 g, 146.77 mmol) and 1-bromo-2-chloroethane (21.05 g, 146.77 mmol) were added. The mixture was stirred at room temperature for one weekend. After completion of the reaction, the mixture was again mixed with water (100 ml) and the organic phase was separated. The organic layer was dried with magnesium sulfate and evaporated under reduced pressure to remove the solvent. Finally, the residue was purified by silica gel column chromatography using hexane and ethyl acetate as eluents to give 6.85 g of 1-Boc-4-(2-chloroethyl)piperazine.