Synthesis of some new azole, pyrimidine, pyran, and benzo/naphtho[b]furan derivatives incorporating thiazolo[3,2‐a]benzimidazole moiety

Reaction ofE‐3‐(N,N‐dimethylamino)‐1‐(3‐methylthiazolo[3,2‐a]benzimidazol‐2‐yl)prop‐2‐en‐1‐one (1) with someN‐nucleophiles, such as anilines2a,2b,2c, 4‐amino‐N‐pyridin‐2‐yl‐benzenesulfonamide (4a), 4‐amino‐N‐pyrimidin‐2‐yl‐benzenesulfonamide (4b), hydrazine, hydroxylamine, thiourea, and guanidine afforded the corresponding arylaminoprop‐2‐en‐1‐one derivatives3a,3b,3c,5a,5b, the pyrazole, isoxazole, pyrimidinethione and aminopyrimidine derivatives7a,7b,9a, and9b, respectively. The utility of compound1, as a versatile building block, for the synthesis of the pyranone13, benzo[b]furan17a, and naphtho[1,2‐b]furan17bwas also explored via its reaction with 2‐benzamidoacetic acid (10), 1,4‐benzoquinone (14a), and 1,4‐naphthoquinone (14b), respectively. J. Heterocyclic Chem., (2011).