Dimethyl oxalate → HCID 178501824, compound

Participants

Reaction Steps

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.

Provenance & Evidence