Solvent free synthesis, anti-inflammatory and anticancer activity evaluation of tricyclic and tetracyclic benzimidazole derivatives.

Heterocyclic benzimidazole derivatives 3a-h, 5a-c and 7a-d have been synthesized by condensation of succinic acid (1) homophthalic acid (4) and 2,3-pyrazinedicarboxlic acid (6) with various substituted diamines under microwave irradiation in good yields. Structures assigned to 3a-h, 5a-c and 7a-d are fully supported by spectral data. All these compounds were screened for anti-inflammatory and anticancer activities. At a dose of 50 mg/kg p.o. compounds 3b (39.4%) and 3c (39.2%) exhibited anti-inflammatory activity, comparable to standard ibuprofen which showed 39% activity at 50 mg/kg p.o. and compound 7c exhibit good anticancer activity against ovary (IGR-OV-1), breast (MCF-7) and CNS(SF-295) human cancer cell lines.