Phosphorus oxychloride → HCID 71743978, compound

Participants

Reaction Conditions

Reaction Steps

In a round-bottomed flask, N-(3,5-difluoro-pyridin-2-ylmethyl)-formamide (crude from Step 2) was dissolved in toluene (14 ml) and phosphorus oxychloride (0.65 ml, 7.0 mmol) was added. The reaction mixture was stirred at 100° C. in an oil bath for 3.5 h then cooled to 0° C. and carefully quenched with ice. Aqueous 25% ammonium hydroxide was added until pH=˜9. The mixture was diluted with water and extracted with dichloromethane (3×). The organic layers were combined, dried over sodium sulfate, filtered and concentrated. The residue was absorbed on silica gel and chromatographed with EtOAc/hexanes (gradient 0-60% EtOAc) to give 319 mg (45%, 2 steps) of 6,8-difluoro-imidazo[1,5-a]pyridine as a yellow solid. 1H NMR (CDCl3, 300 MHz): δ (ppm) 8.36 (d, J=3.0 Hz, 1H), 7.84 (d, J=3.4 Hz, 1H), 7.65 (s, 1H), 6.39-6.57 (m, 1H).

Provenance & Evidence