Antitumour benzothiazoles. Part 20: 3′-Cyano and 3′-Alkynyl-Substituted 2-(4′-Aminophenyl)benzothiazoles as new potent and selective analogues

The synthesis of a new series of antitumour 2-(4-aminophenyl)benzothiazole analogues, substituted in the 3′-position by cyano or alkynyl groups, is described. Several of the analogues, notably the 5-fluorinated compounds 7c and 9c, were found to possess potent in vitro activity against MCF-7 and MDA 468 human cancer cell lines. More comprehensive in vitro analysis (NCI 60-cell line) established compound 7c as a particularly potent and selective 2-(4-aminophenyl)benzothiazole analogue.