Novel Synthesis of Isatin-Thiazole Pharmacophores and their Cytotoxicity Evaluation

Novel synthesis of isatin-thiazole pharmacophores was developed which involves condensation of isatin or halo substituted isatins with phenyl hydrazine, 2-hydrazino-benzothiazole or 2-hydrazino-4-phenyl benzothiazole yielded the corresponding hydrazones which on further di-benzylation or di-methylation yielded 1,2’-dibenzyl or 1,2’-dimethyl substituted hydrazones. Furtherisatin or 7-Chloroisatin on condensation with 1,2-diaminobenzene yielded corresponding 6H-indolo 2,3-bquinoxalines. One of the compound 1-benzyl-5-bromo-7-chloroindoline-2,3-dione (23) shows cytotoxicity activity against breast cancer cell line (MCF7) with IC₅₀ value 27.23 ± 3 μM and also in colorectal cancer cell line (CT26) with IC₅₀ value 17.7 ± 8 μM, which was comparable to that of standard Doxorubicin.