反应详情

A solution of 4-nitro-1,2-phenylenediamine (0.9 g, 5.9 mmol) in 5 ml of isobutyric acid was stirred at reflux for 12 h. The reaction mixture was concentrated in vacuo to yield a dark brown residue, which was dissolved in 100 ml of EtOAc and washed with aqueous NaHCO3. Organic layer was dried over MgSO4 and concentrated in vacuo, yielding an oil which was characterized as 2-isopropyl-5-nitrobenzimidazole and subjected to a following reaction without further purification. The nitrobenzimidazole and 50 mg of 10% Pd-C were dissolved in 100 ml of MeOH and stirred for 12 h under H2. The reaction mixture was filtered and concentrated in vacuo, yielding 0.95 g (5.4 mmol, 92%) of the desired product.

1. temperatureat reflux for 12 h
2. concentrationThe reaction mixture was concentrated in vacuo
3. customto yield a dark brown residue, which
4. washwashed with aqueous NaHCO3
5. dry with materialOrganic layer was dried over MgSO4
6. concentrationconcentrated in vacuo
7. customyielding an oil which
8. customsubjected to a following reaction without further purification
9. filtrationThe reaction mixture was filtered
10. concentrationconcentrated in vacuo