反应详情

温度

100 °C

A stirred mixture of 5-fluoropyridine-2,3-diamine (1.13 g) from Step 1 of this Example, formic acid (0.5 mL), and triethylorthoformate (15 mL) was heated at 100° C. for 1 h. The reaction mixture was cooled to rt, filtered, and the filtrate was concentrated under reduced pressure. The residue was purified via silica gel flash chromatography eluting with 100% DCM to 10% MeOH in DCM to afford 6-fluoro-3H-imidazo[4,5-b]pyridine (760 mg, 36% over two steps) as a yellow solid. 1H NMR (500 MHz, DMSO-d6) δ 13.09 (br s, 1H), 8.49 (s, 1H), 8.37 (s, 1H), 7.97 (d, J=7.9 Hz, 1H). LCMS (ESI) m/z 138 (M+H)+.

1. temperatureThe reaction mixture was cooled to rt
2. filtrationfiltered
3. concentrationthe filtrate was concentrated under reduced pressure
4. customThe residue was purified via silica gel flash chromatography
5. washeluting with 100% DCM to 10% MeOH in DCM