反应详情

To a solution of 5,6-Dimethoxy-1H-benzimidazole (1.0 g, 5.65 mmol) in 1-methyl-2-pyrrolidinone (10 ml) at 0° C. was added NaH (60% dispersion; 339 mg, 8.475 mmol). After gas evolution had stopped, 2,4-Dibromo-thiazole-5-carboxylic acid methyl ester (1.7 g, 5.65 mmol) was added. The resulting solution was stirred at ambient temperature for 1 hr. 50 ml water was added. The suspension was stirred for 10 min and filtered to afford 4-bromo-2-(5,6-dimethoxy-benzoimidazol-1-yl)-thiazole-5-carboxylic acid methyl ester (1.6 g, 73%) as a light brown solid. 1H NMR (300 MHz, CDCl3) δ 3.96 (s, 3H), 3.98 (s, 3H), 4.03 (s, 3H), 7.32 (s, 1H), 7.58 (s, 1H), 8.39 (s, 1H).

1. stirringThe suspension was stirred for 10 min
2. filtrationfiltered