Reactions with Acetoacetanilide : Synthesis and antibacterial activity of some new pyran, pyrano [2, 3-clpyrazole and pyrano [2, 3,-c]-pyridine deerivatives

The reaction of acetoacetanilide (1) with the $\alpha$-cyanocinnamonitrile derivatives 2 yielded the Michael adducts 4 which could be converted into the pyrano [2, 3, -c] pyrazole derivatives 5 via their reaction with hydrazine hydrate. Cyclisation of 4 afforded the derivatives 10. The pyranopyrazoles 9 reacted with different activated nitrile derivatives (3a-c) to give the pyrano [2, 3-c] pyridine derivatives 13. 16 and 19 respectively. The biological activity of the synthesised heterocyclic derivatives was investigated and discussed.