Potassium Carbonate → 3-(difluoromethyl)-6-(3,4-dimethoxyphenyl)-3H-imidazo[4,5-c]pyridin-4(5H)-one

Participants

Reaction Conditions

Reaction Steps

4-(benzyloxy)-6-chloro-3-(difluoromethyl)-3H-imidazo[4,5-c]pyridine 2.28 (113 mg, 0.365 mmol), 3,4-dimethoxyphenylboronic acid (107 mg, 0.588 mmol), bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (14.5 mg, 0.0205 mmol) and K2CO3 (164 mg, 1.19 mmol) were taken up in toluene (3 mL) and water (0.6 mL) under Ar. The stirred mixture was heated to 90° C. After 3.5 h, additional boronic acid (35 mg, 0.19 mmol), catalyst (4.5 mg, 0.0064 mmol), and K2CO3 (53 mg, 0.38 mmol) were added as a suspension in toluene (1 mL) and water (0.3 mL). After an additional 1 h, the reaction mixture was cooled to r.t. and was diluted with EtOAc (20 mL) and water (20 mL). The phases were separated, and the aqueous phase was extracted with EtOAc (20 mL). The organic phase was dried over Na2SO4, filtered, and concentrated onto silica gel. Purification by silica gel chromatography (20% to 50% acetone in hexanes) provided a residue that was dissolved in EtOH (3 mL) and DMF (2 mL). Ammonium formate (260 mg, 4.1 mmol) and Pd(OH)2 on carbon (20 wt. % Pd, 40 mg) were added and the mixture was heated to 70° C. and stirred for 20 min. The mixture was diluted with DMF (5 mL) and filtered through Celite. The filtrate was concentrated in vacuo and the resulting crude solid was purified by silica gel chromatography (0% to 10% MeOH in DCM) to provide 3-(difluoromethyl)-6-(3,4-dimethoxyphenyl)-3H-imidazo[4,5-c]pyridin-4(5H)-one 2.29.

Provenance & Evidence