Water → 2-(5,6-Dimethoxybenzoimidazol-1-yl)-4-phenylthiazole-5-carboxylic acid

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Reaction Steps

2-(5,6-Dimethoxybenzoimidazol-1-yl)-4-phenylthiazole-5-carboxylic acid ethyl ester (180 mg, 0.44 mmol) was suspended in THF (4 ml), NaOH (15%, 1.5 ml) and water (2 ml) and the mixture was stirred at 40-50° C. for 3 hrs. After THF was removed, the residue was extracted with ethyl acetate (2×2 mL). The aqueous was then neutralized with 3N HCl to pH=3. The solid was collected by filtration and was washed with water, dried in airflow to give 2-(5,6-Dimethoxybenzoimidazol-1-yl)-4-phenylthiazole-5-carboxylic acid (147 mg, 0.38 mmol, 88%). 1H-NMR (DMSO-D6) 8.74 (s, 1H); 7.80 (s, 1H); 7.57-7.63 (m, 2H); 7.40-7.56 (m, 3H); 7.38 (s, 1H); 3.83 (d, 6H). MS M/z 382 (M+1).

Provenance & Evidence