Synthesis of novel benzo[4,5]thiazolo[1,2-a]pyrimidine-3-carboxylate derivatives and biological evaluation as potential anticancer agents

•To discover and develop tumour growth inhibitors.•Synthesis of several new benzo[4,5]thiazolo[1,2-a]pyrimidine-3-carboxylate analogues.•Compounds 5a and 5b exhibited potent cytotoxicity against MDA-MB-231 and MCF-7 cells.

A novel series of building blocks consisting of benzo[4,5]thiazolo[1,2-a]pyrimidine-3-carboxylate have been synthesized as potential anticancer compounds. These compounds were prepared from 2-aminobenzothiazole, benzaldehyde and ethyl acetoacetate in ethylene glycol by catalysing with TBAHS to give benzo[4,5]thiazo[1,2-a]pyrimidine derivative 4 followed by the formation of amide by reaction with several secondary amines in good yields. The cytotoxicity of these compounds was evaluated against human cancer cell lines in vitro (A549, HeLa, MDA-MB-231 and MCF-7). Compound 5b exhibited promising cytotoxicity with IC50 values of 0.58 and 1.58 μM specifically against human breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231, while compound 5a showed promising cytotoxicity against MDA-MB-231 (IC50 value of 5.01 μM).

Graphical abstractA novel series of building blocks consisting of benzo[4,5]thiazolo[1,2-a]pyrimidine-3-carboxylate as potential tumour growth inhibitors were synthesized and screened for their cytotoxicity against the human cancer cell lines in vitro.Figure optionsDownload full-size imageDownload as PowerPoint slide