反应详情

3-Acetylbenzoic acid (1.64 g, 10.0 mmol), 1-tert-butoxycarbonylpiperazine (2.23 g, 12.0 mmol), HATU (4.56 g, 12.0 mmol) and HOAT (1.63 g, 12.0 mmol) were dissolved in 20 mL anhydrous DMF in a 100 mL round-bottom flask under a positive pressure of N2 in an ice bath. DIPEA (3.8 mL, 22.0 mmol) was added and the mixture stirred at ambient temperature for 2 h. The solution was diluted with 100 mL of EtOAc and washed with 40 mL each: 0.2 N NaOH solution once and saturated NaCl solution twice. The organic layer was dried over Na2SO4, filtered, concentrated and purified by silica gel chromatography using EtOAc-hexanes (2:1 v/v) as the eluant to give tert-butyl 4-(3-acetylbenzoyl)piperazine-1-carboxylate as 2.97 g of white solid.

1. washwashed with 40 mL each
2. dry with materialThe organic layer was dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated
5. custompurified by silica gel chromatography