Synthesis and Anti‐inflammatory Screening of Some Mono and Bis‐Alkoxyphthalimide Linked Benzimidazole and their Quinazoline and Pyrimidine Derivatives

In the present study, synthesis of some nonsymmetrical 2‐(1H‐benzimidazol‐2‐ylamino)‐7,7‐dimethyl‐7,8‐dihydroquinazolin‐5(6H)‐one (3) and substituted‐(1H‐benzo[d]imidazol‐2‐yl)amino‐pyrimidine derivatives (4a, 4b, 4c and 5a, 5b) is described as a three‐component reaction of 2‐guanidinobenzimidazole (2) with triethyl orthoformate and different reactive methylene compounds. Subsequent condensation of compounds 3, 4a, 4b, 4c, and 5a, 5b with bromoethoxyphthalimide (1) gave final compounds 6, 7a, 7b, 7c, and 8a, 8b. Synthesized final compounds have been screened for their in‐vivo anti‐inflammatory activity against carrageenan‐induced paw edema in albino rats. Diclofenac was used as standard anti‐inflammatory agents. Some of the compounds exhibited significant anti‐inflammatory activity, as compared to standard drug. Structures of synthesized compounds have been confirmed on the basis of chemical tests and spectral studies.