反应详情

The solution of the title compound from Example 3 (2.52 g, 6.98 mmoles) and acetic anhydride (1.0 g, 9.8 mmoles) in pyridine (25 ml) was stirred for 60 hours at room temperature. The crude reaction mixture was partitioned between ethyl acetate and 5% aqueous hydrogen chloride. The organic layer was washed with distilled water, saturated sodium hydrogen carbonate solution, saturated sodium chloride solution, and dried over anhydrous magnesium sulfate. The solvent was recovered under vacuum to obtain 2.97 g of a white solid. The crude reaction product was recrystallized from ethanol in two crops to obtain 2.24 g of the title compound as a pure white solid, m.p. 239°-240° C. 1H NMR (DMSO-d6) δ 9.36 (s, 1H), 7.63 (m, 3H), 7.35 (m, 2H), 7.20 (m, 3H), 6.97 (d, J=8.80 Hz, 1H), 5.23 (m, 2H), 2.17 (s, 3H), 1.34 (s, 3H), 1.25 (s, 3H). 13C NMR (DMSO-d6) δ 169.69, 158.69, 155.75, 136.95, 132.94, 132.66, 129.03, 125.28, 124.25, 123.79, 118.86, 118.09, 116.62, 103.31, 78.43, 72.07, 49.49, 25.85, 20.67, 19.54.

1. customThe crude reaction mixture
2. customwas partitioned between ethyl acetate and 5% aqueous hydrogen chloride
3. washThe organic layer was washed with distilled water, saturated sodium hydrogen carbonate solution, saturated sodium chloride solution
4. dry with materialdried over anhydrous magnesium sulfate
5. customThe solvent was recovered under vacuum