反应详情

A 100 mL flask was charged with the product from Example 1B (2.8 g, 18 mmol), 1,1′-carbonyldiimidazole (2.9 g, 18 mmol) and ethyl acetate (20 mL). The mixture was stirred under nitrogen at ambient temperature for 4 hours, then 20 mL of concentrated ammonium hydroxide was added and the mixture stirred for 18 hours. The mixture was diluted with ethyl acetate (50 mL) and the layers were separated. The organic extract was washed with water (3×15 mL), dried over magnesium sulfate and concentrated under reduced pressure. The crude product was treated with carbon and recrystallized from aqueous methanol to provide the title compound as white crystals (3 g, 78% yield). 1H NMR (CDCl3, 300 MHz) δ 5.55 (s, 2H), 1.3-1.7 (m, 10H), 1.28 (dd, 1H), 1.11 (t, 1H), 0.75 (dd, 1H); 13C NMR (CDCl3, 100 MHz) δ 174.1, 37.6, 28.9, 28.6, 27.5, 26.2, 25.8, 25.6, 19.4; MS m/z 154 (M+H)+.

1. stirringthe mixture stirred for 18 hours
2. customthe layers were separated
3. extractionThe organic extract
4. washwas washed with water (3×15 mL)
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. additionThe crude product was treated with carbon
8. customrecrystallized from aqueous methanol