New approaches for the synthesis of pyrazole, thiophene, thieno[2,3-b]pyridine, and thiazole derivatives together with their anti-tumor evaluations

Abstract

The reaction of cyanoacetylhydrazine (1) with acetylchloride (2) gave the N-acyl derivative 3. The latter underwent ready cyclization in sodium ethoxide to give the pyrazole derivative 4 which was the key compound for the synthesis of thiophene, thieno[2,3-b]pyridine, and thiazole derivatives. The anti-tumor evaluations of the newly synthesized products against the three human tumor cell lines, namely, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460), and CNS cancer (SF-268), were studied. Some of these compounds were found to exhibit much higher inhibitory effects toward the three tumor cell lines than the reference doxorubicin. Molecular modeling of the four compounds 12c, 12f, 16a, and 16d, which showed the maximum inhibitory effect, were done.