反应详情

The diamine (6.7 g, 0.035 mol) (obtained in step 4 above) was dissolved in ethanol (20 mL) and added to a stirred mixture of carbon disulfide (3.0 g, 0.04 mol), potassium hydroxide (2.3 g, 0.04 mol), water (5 mL) and ethanol (15 mL). The resultant solution was refluxed for 6 h. Animal charcoal (2.0 g) was added and further refluxed for 1 h. The mixture was filtered and washed with hot water. A mixture of acetic acid and water (1:2, 15 mL) was added to the filtrate slowly with vigorous stirring to separate 6-fluoro-5-(imidazol-1-yl)-2-mercapto-1H-benzimidazole (5.0 g, 60%) as a brown solid. mp 280° C. (decomp.); IR (KBr) 3078, 1481 cm-1 ; 1H NMR (DMSO-d6) δ 2.20 (s, 1H, SH), 7.10 (s, 1H), 7.24 (d, J=6.0 Hz, 1H), 7.26 (d, J=4.1 Hz, 1H), 7.56 (s, 1H), 8.00 (s, 1H), 12.90 (brs, 1H, NH); Mass (m/z) 234 (M+.).

1. temperaturefurther refluxed for 1 h
2. filtrationThe mixture was filtered
3. washwashed with hot water
4. additionA mixture of acetic acid and water (1:2, 15 mL)
5. additionwas added to the filtrate slowly
6. customto separate 6-fluoro-5-(imidazol-1-yl)-2-mercapto-1H-benzimidazole (5.0 g, 60%) as a brown solid