Bromocyclopentane → 3-Cyclopentyl-3H-imidazo[4,5-b]pyridin-5-ol

Participants

Reaction Steps

5-(Benzyloxy)-3H-imidazo[4,5-b]pyridine (0.300 g, 1.33 mmol) was dissolved in THF and NaH (0.050 g, 2.0 mmol) was added portionwise. The resulting mixture was heated in a sealed tube for 1 h and then cooled to room temperature. Bromocyclopentane (0.20 g, 17.8 mmol) was added and the reaction was heated to 70° C. overnight. The solution was then diluted with ether and washed with water. The aqueous layer was back extracted with additional ether and the combined organic portions were washed with brine, dried over MgSO4 and purified by preparative HPLC. The resulting 5-(benzyloxy)-3-cycloheptyl-3H-imidazo[4,5-b]pyridine was then dissolved in DCM and diluted with excess sulfuric acid. The resulting solution was stirred for 30 minutes at room temperature then acidified with the addition of 1 M aqueous hydrochloric acid. The solvent was removed from the organic layer and the residue was purified via preparative HPLC to give the title compound (0.0284 g). LCMS m/z=204.31 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.65-1.80 (m, 2H), 1.80-1.95 (m, 2H), 2.0-2.1 (m, 2H), 2.15-2.30 (m, 2H), 4.95-5.05 (m, 1H), 6.88 (d, J=8.8 Hz, 1H), 8.13 (d, J=8.8 Hz, 1H), 9.35 (s, 1H).

Provenance & Evidence