反应详情

To a solution of the compound of example 45 (3.83 g, 15 mmol) and di-t-butyl carbonate (3.60 g, 16.5 mmol) in acetonitrile was added 4-dimethylaminopyridine (0.18 g, 1.5 mmol). The solution was stirred at RT for 1 day, additional di-t-butyl carbonate (3.60 g) was added and stirring was continued for 3 days. Additional di-t-butyl carbonate (3.60 g) was added and the reaction was stirred overnight and concentrated. The residue was diluted with ether, washed with sat citric acid, sat NaHCO3, brine, dried (MgSO4) and concentrated to afford the title compound. The crude product was purified by flash chromatography (ethyl acetate/hexanes) and recrystallization from hexanes (-78° C.) to afford the title compound as a white solid (2.65 g, 50%). m.p. 51°-52° C.

1. stirringstirring
2. waitwas continued for 3 days
3. stirringthe reaction was stirred overnight
4. concentrationconcentrated
5. additionThe residue was diluted with ether
6. washwashed
7. dry with materialdried (MgSO4)
8. concentrationconcentrated