Abstract
A new series of pentaheterocycles, namely, benzo[5',6'] pyrano[4',3':4,5] pyrido[2,3-d] triazolo[4,3-a] pyrimidine-7,13(3H)-diones 10 was prepared via the reaction of hydrazonoyl chlorides 7 with 2,4-dihydro-3-thioxo-benzo[5', 6'] pyrano[3', 4': 5,6] pyrido[2,3-d] pyrimidine-1,7dione 4 in presence of chitosan as ecofriendly catalyst. The structure of the newly synthesized compounds were established on the basis of spectral data (Mass, IR, 1 H and 13 C NMR) and elemental analyses.