Water → methyl 3-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-3H-imidazo[4,5-b]pyridine-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of methyl 3H-imidazo[4,5-b]pyridine-6-carboxylate (1.34 g, 7.56 mmol) from Step 2 of this Example in anhydrous DMF (25 mL) at 0° C. was added in one portion sodium hydride (60% dispersion in mineral oil, 333 mg, 8.32 mmol) and the mixture was stirred at 0° C. for 30 min. To the reaction mixture was added a solution of 6-(chloromethyl)-2-(methylthio)benzo[d]thiazole (1.3 g, 5.66 mmol) from Step 4 of Example 36 in DMF (5 mL). The mixture was allowed to warm to rt then stirred for a further 15 h. To the reaction mixture was added water (300 mL) and the mixture was extracted with EtOAc (3×50 mL). The combined organic layers were washed with water and then brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography eluting with 100% DCM followed by 1% MeOH in DCM to afford methyl 3-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-3H-imidazo[4,5-b]pyridine-6-carboxylate (1.3 g, 46%) as a white solid. The regiochemistry of the alkylation was determined by 2-dimensional nuclear Overhauser effect (NOE) experiment. 1H NMR (300 MHz, DMSO-d6) δ 8.95 (d, J=1.9 Hz, 1H), 8.81 (s, 1H), 8.56 (d, J=1.7 Hz, 1H), 8.00 (d, J=1.1 Hz, 1H), 7.80 (d, J=8.5 Hz, 1H), 7.47 (dd, J=1.6, 8.4 Hz, 1H), 5.66 (s, 2H), 3.90 (s, 3H), 2.76 (s, 3H). LCMS (ESI) m/z 371 (M+H)+.

Provenance & Evidence