反应详情

A solution of 3-methyl-1,2-diaminobenzene (5.00 g, 40.9 mmol) in formic acid (25 mL) was heated at 105° C. for 2 h. The reaction mixture was allowed to cool and then concentrated ammonium hydroxide (50 mL) was added dropwise. The mixture was extracted with dichloromethane (2×100 mL). The extracts were washed with brine, dried (Na2SO4), treated with charcoal, filtered, and evaporated to dryness. The residue was triturated with cold ether, filtered, and washed with cold ether, ether/hexane (1:1), and hexane to give 4-methylbenzimidazole (3.85 g, 71%) as a yellow solid.

1. temperatureto cool
2. extractionThe mixture was extracted with dichloromethane (2×100 mL)
3. washThe extracts were washed with brine
4. dry with materialdried (Na2SO4)
5. additiontreated with charcoal
6. filtrationfiltered
7. customevaporated to dryness
8. customThe residue was triturated with cold ether
9. filtrationfiltered
10. washwashed with cold ether, ether/hexane (1:1), and hexane