反应详情

A mixture of 4-(3,5-difluoro-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester from step (b) above (140 mg, 0.47 mmol) and 4 M solution of HCl in dioxane (1 mL, Aldrich) was stirred at room temperature for 30 h. The solvent was evaporated in vacuo and the residue was dissolved in EtOAc (30 mL). The solution was washed successively with 1 N NaOH (20 mL) and brine (20 mL), dried over MgSO4, filtered, and the solvent was removed in vacuo. The residue was purified by silica gel chromatography, eluting with 10% MeOH in CH2Cl2 to give the title compound as a white solid. MS (ESI, pos. ion) m/z: 200 (M+1).

1. customThe solvent was evaporated in vacuo
2. dissolutionthe residue was dissolved in EtOAc (30 mL)
3. washThe solution was washed successively with 1 N NaOH (20 mL) and brine (20 mL)
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. customthe solvent was removed in vacuo
7. customThe residue was purified by silica gel chromatography
8. washeluting with 10% MeOH in CH2Cl2