Potassium Carbonate → methyl 1-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-1H-imidazole-4-carboxylate

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Reaction Steps

To a stirred mixture of 6-(chloromethyl)-2-(methylthio)benzo[d]thiazole (500 mg, 2.2 mmol) from Example 36 and methyl 4-imidazole carboxylate (400 mg, 3.3 mmol) in DMF (15 mL) was added K2CO3 (0.9 g, 6.5 mmol). After the mixture was stirred for 3 h at rt, it was partitioned between EtOAc (100 mL) and water (50 mL). The EtOAc layer was separated and washed with water (50 mL) and brine (50 mL), then dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography eluting with 2% MeOH in CH2Cl2 to afford methyl 1-((2-(methylthio)benzo[d]thiazol-6-yl)methyl)-1H-imidazole-4-carboxylate (130 mg, 19%) 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 8.01 (d, J=0.9 Hz, 1H), 7.98 (d, J=1.1 Hz, 1H), 7.93 (d, J=0.9 Hz, 1H), 7.84 (d, J=8.3 Hz, 1H), 7.43 (dd, J=1.7, 8.3 Hz, 1H), 5.35 (s, 2H), 3.72 (s, 3H), 2.78 (s, 3H). LCMS (ESI) m/z 322 (M+H)+.

Provenance & Evidence