反应详情

温度

160 °C

To a stirred solution of N-(3-hydroxypyridin-4-yl)-5-nitrothiophene-2-carboxamide (1.1 g, 4.1 mmol) in pyridine (5 mL) was added P2O5 (1.2 g, 8.3 mmol) and p-xylene (21 mL). After refluxing at 160° C. overnight, the reaction mixture was concentrated in vacuo and the residue was purified by chromatography on silica gel eluted with 5% of ethyl acetate in CH2Cl2 to give 2-(5-nitrothiophen-2-yl)oxazolo[5,4-c]pyridine as brown solid (174 mg, yield 17%). 1H NMR (400 MHz, CDCl3) δ: 8.97 (1H, s); 8.59 (1H, d, J=5.6); 7.94 (1H, d, J=4.4); 7.86 (1H, d, J=4.4), 7.69 (1H, d, J=5.6, 0.8).

1. concentrationthe reaction mixture was concentrated in vacuo
2. customthe residue was purified by chromatography on silica gel
3. washeluted with 5% of ethyl acetate in CH2Cl2