Synthesis and cytotoxicity testing of novel 2-(3-substituted-6-chloro-1,1-dioxo-1,4,2-benzodithiazin-7-yl)-3-phenyl-4(3H)-quinazolinones

A new series of thirteen 2-[3-(substituted amino)-6-chloro-1,1-dioxo-1,4,2-benzodithiazin-7-yl]-3-phenyl-4(3H)-quinazolinones 4-16 were prepared in order to evaluate their cytotoxic activity against 12 human cancer cell lines. The bioassay indicated that the quinazolinone derivatives 5, 8-12, 15, and 16 possess cancer-cell growth-inhibitory properties. Compounds 5 and 12 showed a high level of selectivity for certain cell lines. The most active compounds 9, 10, 15, and 16 showed moderate antiproliferative activity and were approximately 4-fold less potent than cisplatin.