Exceedingly facile one-pot protocols to the synthesis of pyrimido annulated analogues of carbazolo condensed azepinones and their evaluation for analgesic activity
Extremely simple protocols based on the reactivity of corresponding oxoketenedithioacetal (4), 2-(dimethylaminomethylene) ketone (5), β-oxoenolether (6) and α,β-unsaturated ketone (7) derivatives of 7-ethyl-3, 4-dihydroazepino[3,2-b]carbazol-2,5(1H,7H)-dione (3) have been developed to provide an easy access to their pyrimido annulated analogues (8-15) of medicinal interest. The key compound 3 from which, the synthesis proceeded has been realized in two steps from the commercial 3-amino-9-ethyl carbazole (1) on its reaction in the first step with ethyl succinyl chloride followed by cyclocondensation of the resulting ester 2 with PPA. The selected synthesized compounds were screened for in-vivo analgesic activity using acetic acid induced writhing model in mice. Among them, compound 13was found to be most active and found comparable to standard aspirin.
KEY WORDS: 3-Amino-9-ethyl carbazole, Oxoketnedithioacetal, Dimethyl formamide dimethyl acetal, 2-(Dimethylaminomethylene)ketone, Oxoenolether, Chalcone
Bull. Chem. Soc. Ethiop. 2017, 31(1), 93-105.