In this study, the pyrrolo[2,1-a]isoquinolines 4a-n were synthesized in good yields in a three steps synthesis from the corresponding α,β-unsaturated esters starting materials. These compounds were tested on six human cancer cells lines to measure the cytotoxic activity as a function of the electronic properties and aromaticity of the substituent at the C-2 position of the pyrroloisoquinoline. Our results reveal that the cytotoxic activity could be explained in terms of the distribution of electronic density across the ring joined to C-2. Also, this study identified 3-hydroxy (4d) and 3-chloro (4j) derivatives with powerful cytotoxic activities. The IC50 values of these compounds were found to be comparable to those of the commercially available Topotecan, Irinotecan, Etoposide, Tamoxifen, and Cisplatin.
Keywords: cytotoxic activity; pyrrolo[2,1-a]isoquinoline; synthesis.