反应详情

To a stirred solution of sodium t-butoxide (0.52 g, 5.23 mmol) in anhydrous THF (13 mL) at room temperature was added dropwise dimethyl oxalate (0.42 g, 3.48 mmol) in THF (6 mL) followed by 3-acetyl-1,5-dibenzyl-1H-pyridin-4-one 14 (0.55 g, 1.74 mmol) in THF (8 mL). The resulting mixture was stirred at room temperature for 4 h and then acidified (pH=6). The crude product was extracted with ethyl acetate (100 mL), washed with water (2×100 mL) and brine (2×100 mL), and dried over anhydrous sodium sulfate and the solvent was distilled off. The residue was purified by ion exchange chromatography (diethylamino sephadex anion exchange resin (CH3CN:H2O, 1:1) and then by flash chromatography on silica gel (chloroform, 100%). Yield 0.44 g (63%), mp 148-150° C. 1H NMR (CDCl3, 500 MHz): δ 8.34 (d, J=2.5, 1H), 8.12 (s, 1H), 7.40-7.12 (m, 10H), 6.91 (d, J=2.3, 1H), 4.94 (s, 2H), 3.88 (s, 3H), 3.82 (s, 2H). 13C NMR (CDCl3, 125 MHz): δ 187.2, 175.2, 170.3, 162.7, 143.9, 138.4, 136.9, 136.1, 133.8, 129.4, 129.5, 129.3, 129.1, 129.1, 128.7, 128.6, 127.5, 127.4, 126.5, 120.2, 102.4, 61.2, 53.0, 33.5. HRMS (M+H)+ calcd for C24H22NO5 404.1498, found 404.1497.

1. extractionThe crude product was extracted with ethyl acetate (100 mL)
2. washwashed with water (2×100 mL) and brine (2×100 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. distillationthe solvent was distilled off
5. customThe residue was purified by ion exchange chromatography (diethylamino sephadex anion exchange resin (CH3CN:H2O, 1:1)