反应详情

To a stirred solution of N-(ethoxycarbonyl-methyl)-N′-(2-hydroxy-1-propyl)oxamide (8.0 g, 34.5 mmol), as prepared in the preceding step, in water (50 mL) under nitrogen at 50° C. was added ruthenium (III) chloride hydrate (75 mg, 0.35 mmol). The reaction flask was removed from the heating bath, and a solution of sodium bromate (5.2 g, 34.5 mmol) in water (40 mL) was added dropwise. The reaction mixture was allowed to cool to room temperature, and then diluted with ethyl acetate and brine. The aqueous layer was extracted with ethyl acetate (2×), then saturated with sodium chloride and extracted again (×2). The combined ethyl acetate layers were washed with brine, dried over Na2SO4, and treated with activated carbon. Evaporation of the solvent and drying under high vacuum provided the title compound as a white solid (7.3 g, 92%). 1H NMR (400 MHz, CDCl3) δ 7.99 (s(br), 1H), 7.84 (s(br), 1H), 4.24 (q, 2H, J=7.1 Hz), 4.19 (d, 2H, J=5.2 Hz), 4.10 (d, 2H, J=5.7 Hz), 2.24 (s, 3H), 1.30 (t, 3H, J=7.1 Hz).

1. customThe reaction flask was removed from the heating bath
2. extractionThe aqueous layer was extracted with ethyl acetate (2×)
3. extractionsaturated with sodium chloride and extracted again (×2)
4. washThe combined ethyl acetate layers were washed with brine
5. dry with materialdried over Na2SO4
6. additiontreated with activated carbon
7. customEvaporation of the solvent
8. customdrying under high vacuum