反应详情

温度

80 °C

A mixture of 2-methyl-4-[(phenylmethyl)oxy]-1H-benzimidazole-6-carboxylic acid (10.0 g, 35.4 mmol, STEP 4 in Example 1), and thionyl chloride (5.2 mL, 7.1 mmol) in methanol (300 mL) was stirred at 80° C. for 3 hours. The mixture was diluted with ethyl acetate, and washed with saturated ammonium chloride aqueous solution. The organic layer was dried over magnesium sulfate, and concentrated in vacuum. The residue was diluted with methanol, filtered to remove the precipitate, and the filtrate was concentrated in vacuum. The resulted solid was washed with dichloromethane to give the title compound as a brown solid (29.8 g, crude), which was used in the next step without further purification. MS (ESI) m/z: 297 (M+H)+, 295 (M−H)−.

1. washwashed with saturated ammonium chloride aqueous solution
2. dry with materialThe organic layer was dried over magnesium sulfate
3. concentrationconcentrated in vacuum
4. additionThe residue was diluted with methanol
5. filtrationfiltered
6. customto remove the precipitate
7. concentrationthe filtrate was concentrated in vacuum
8. washThe resulted solid was washed with dichloromethane