Abstract
A novel series of 2-ethylidenehydrazono-5-arylazothiazoles 5a-h and 2-ethylidenehydrazono-5-arylazothiazolones 9a-d were prepared by cyclocondensation of hydrazonyl halides 3a-h and 7a-d with ethylidenethiosemicarbazide 2. In addition, reaction of 2 with N-phenyl-carbohydrazonyl chloride (14), afforded 1,3,4-thiadiazole derivative 17 as the end product. Moreover, the thiosemicarbazide derivative 2 was reacted with various bromoacetyl compounds 19a-d and 1,1'-(1,4-phenylene)bis(2-bromoethanone) (21) furnished the respective thiazole derivatives 20a-d and 1,4-phenylene-bis-thiazole derivative 22. The structures of the newly synthesized compounds were established on the basis of spectroscopic evidences and their alternative syntheses. The newly synthesized compounds were evaluated for their antitumor activities against hepatocellular carcinoma (HepG2) cell line and the results revealed promising activities of compounds 5h, 5d, 5g, 5f and 5e with IC50 equal 2.23 +/- 0.28, 2.48 +/- 0.34, 2.49 +/- 0.24, 4.03 +/- 0.11, and 5.32 +/- 0.27 mu M, respectively.