|
[摘要]:Cyclization of (non)-methylated nitro-o-phenylenediamines with cyanogen bromide provided nitro-substituted 2-aminobenzimidazoles in good up to excellent yields. Catalytic hydrogenation of 2-amino-1-methyl-5-nitrobenzimidazole yielded 2,5-diamino-1-methylbenzimidazole, which on treatment with 1,1,3,3-tetramethoxypropane in methanol and subsequently after removal of methanol in polyphosphoric acid afforded food-borne carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in 20% yield. J. Heterocyclic Chem.,(2011). |
|