反应详情

温度

120 °C

A 2-neck flask (20 mL) equipped with reflux condenser was charged with 2-methyl-1-phenylbenzimidazole-5-carboxylic acid (see Synthesis Example 1-3) (0.15 g, 0.59 mmol) and polyphosphoric acid (approx. 2 g), and this was heated to 120° C. To this was added 1,2-diaminobenzene (0.09 g, 0.83 mmol), and this was heated to 160° C. and stirred under those conditions for 20 hours. After being allowed to cool to room temperature, ice was added and concentrated aqueous ammonia (28%) was added to the liquid to give approx. pH 9. The precipitated crystals were filtered off, these were washed with distilled water (approx. 3 mL, 2 times), and then dried to yield the title compound (0.25 g, quant.) as greenish pale yellow crystals.

1. customA 2-neck flask (20 mL) equipped
2. temperaturewith reflux condenser
3. temperaturethis was heated to 160° C.
4. temperatureto cool to room temperature
5. additionice was added
6. customto give approx. pH 9
7. filtrationThe precipitated crystals were filtered off
8. washthese were washed with distilled water (approx. 3 mL, 2 times)
9. customdried