反应详情

A mixture of 3-(4-hydroxyphenyl)-3H-imidazo[4,5-b]pyridine-6-carboxylic acid (54 mg, 0.21 mmol), tetrabutylammonium iodide (8 mg, 0.021 mmol), 4-(trifluoromethoxy)benzyl bromide (0.13 mL, 0.84 mmol) and sodium hydride (50.4 mg, 1.26 mmol) in DMF (3 mL) was stirred at rt under nitrogen for 4 h. Then, water (3 mL) was added and the mixture washed with EtOAc (10 mL). The aqueous phase was acidified with 6N HCl(aq) and the resulting precipitate isolated by filtration. The EtOAc wash was concentrated in vacuo and the residue dissolved in MeOH and stirred with 6N NaOH(aq) for 2 h prior to acidification (2M HCl(aq) and filtration of product. The combined solids were dried in vacuo to give 3-{4-[(4-(trifluoromethoxy) benzyl)oxy]phenyl}-3H-imidazo[4,5-b]pyridine-6-carboxylic acid. 1H NMR (400 MHz, D6-DMSO) δ 5.26 (s, 2H), 7.26 (d, J=8.9 Hz, 2H), 7.42 (d, J=8.2 Hz, 2H), 7.63 (d, J=8.2 Hz, 2H), 7.82 (d, J=8.9 Hz, 2H), 8.61 (d, J=1.6 Hz, 1H), 8.95 (s, 1H), 8.97 (d, J=1.6 Hz, 1H) and 13.2 (br.s, 1H); MS (ES+): m/z 430 [MH+].

1. washthe mixture washed with EtOAc (10 mL)
2. customthe resulting precipitate isolated by filtration
3. washThe EtOAc wash
4. concentrationwas concentrated in vacuo
5. dissolutionthe residue dissolved in MeOH
6. stirringstirred with 6N NaOH(aq) for 2 h
7. filtrationto acidification (2M HCl(aq) and filtration of product
8. customThe combined solids were dried in vacuo