Potassium Carbonate → 6-((4-bromo-1H-imidazol-1-yl)methyl)-2-(methylthio)benzo[d]thiazole

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Reaction Steps

To a stirred mixture of 6-(chloromethyl)-2-(methylthio)benzo[d]thiazole (0.2 g, 0.9 mmol) from Step 4 of this Example and 4-bromo-1H-imidazole (0.2 g, 1.3 mmol) in anhydrous DMF (3.0 mL) was added K2CO3 (0.37 g, 2.7 mmol). After stirred for 3 h at rt, the reaction mixture was partitioned between EtOAc (100 mL) and water (50 mL). The EtOAc layer was separated, washed with brine (50 ml), dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography eluting with a gradient of 30% EtOAc in hexanes to 100% EtOAc to afford 6-((4-bromo-1H-imidazol-1-yl)methyl)-2-(methylthio)benzo[d]thiazole (160 mg, 54%) as a yellow oil. The regiochemistry of the alkylation was determined by 2-dimensional nuclear Overhauser effect (NOE) experiment. 1H NMR (300 MHz, CDCl3) δ 7.85 (d, J=8.3 Hz, 1H), 7.54 (d, J=1.1 Hz, 1H), 7.45 (d, J=1.3 Hz, 1H), 7.24 (dd, J=1.7, 8.5 Hz, 1H), 6.88 (d, J=1.5 Hz, 1H), 5.17 (s, 2H), 2.80 (s, 3H). LCMS (ESI) m/z 340 and 342 (M+H)+.

Provenance & Evidence