反应详情

温度

200 °C

A mixture of 6-3 (300 mg, 1.37 mmol, 1 equiv) and 1,2-phenylenediamine (223 mg, 2.06 mmol, 1.5 equiv) in polyphosphoric acid (8 mL) was heated at 200° C. for 3 h. The hot rxn mixture was poured into ice water (50 mL), and the resulting mixture was allowed to stand until all polyphosphoric acid had dissolved. The acidic suspension was neutralized with saturated aqueous sodium bicarbonate solution, then extracted with ethyl acetate (5×100 mL). The combined organic layers were dried over sodium sulfate and concentrated. The residue was purified by flash column chromatography (EtOAc) to afford 3-(1H-benzoimidazol-2-yl)-1H-[1,7]naphthyridine-2-one (6-4) as a yellow solid. 1H NMR (400 MHz, (CD3)2SO) δ 12.75 (s, 1H), 12.71 (s, 1H), 9.13 (s, 1H), 8.79 (s, 1H), 8.43 (d, 1H, J=5.2 Hz), 7.91 (d, 1H, J=5.2 Hz), 7.74 (m, 1H), 7.68 (m, 1H), 7.24 (m, 2H). HRMS (electrospray FT/ICR) calculated for C15H11N4O [M+H]+ 263.0933, found 263.0930.

1. dissolutionhad dissolved
2. extractionextracted with ethyl acetate (5×100 mL)
3. dry with materialThe combined organic layers were dried over sodium sulfate
4. concentrationconcentrated
5. customThe residue was purified by flash column chromatography (EtOAc)