Pyrrolo[2,1-d][1,2,3,5]tetrazinones deaza analogues of temozolomide with potent antitumor activity

The title compounds, that hold the deaza skeleton of temozolomide, exhibited potent in vitro antiproliferative activity. An evaluation of such a biological activity indicates that the mode of action of these compounds differs from that of temozolomide and is also mechanistically unrelated to that of any known antitumor drug.