1,2,4-benzotriazine oxides as radiosensitizers and selective cytotoxic agents

A method of selectively killing hypoxic tumor cells sensitive to the formula in a host comprising administering to said host an effective amount of a pharmaceutical composition comprising a compound of the formula ##STR24## wherein X is NH.sub.2 ;

• NHR or NRR;
• wherein each R is independently an alkyl of 1-4 carbon atoms or acyl of 1-4 carbon atoms, or wherein in the case of NRR the two R groups may be linked together to form a morpholino, pyrrolidino or piperidino ring, and wherein R may be further substituted with OH,. NH.sub.2, alkyl (1-4C) secondary amino, dialkyl (1-4C) tertiary amino, morpholino, pyrrolidino, piperidino, alkoxy (1-4C), or halogen substituents;
• n is 1;
• and
• Y.sup.1 and Y.sup.2 are independently either H;
• nitro, halogen;
• hydrocarbyl (1-14C) including cyclic and unsaturated hydrocarbyl, optionally substituted with 1 or 2 substituents selected from the group consisting of halogen, hydroxy, epoxy, alkoxy (1-4C), alkylthio (1-4C), primary amino (NH.sub.2), lower alkyl (1-4C) secondary amino, dialkyl (1-4C) tertiary amino, dialkyl (1-4C) tertiary amino where the two alkyls are linked together to produce a morpholino, pyrrolidino or piperidino, acyloxy (1-4C), acylamido (1-4C) and thio analogs thereof, acetylaminoalkyl (1-4C), carboxy, alkoxycarbonyl (1-4C), carbamyl, alkylcarbamyl (1-4C), alkylsulfonyl (1-4C) or alkylphosphonyl (1-4C), wherein the hydrocarbyl can optionally be interrupted by a single ether (--O--) linkage;
• or wherein Y.sup.1 and Y.sup.2 are independently either morpholino, pyrrolidino, piperidino, NH.sub.2, NHR', NR'R' O(CO)R', NH(CO)R', O(SO)R', or O(POR')R' in which R' is a hydrocarbyl (1-4C) which may be substituted with OH, NH.sub.2, alkyl-(1-4C) secondary amino, dialkyl (1-4C) tertiary amino, morpholino, pyrrolidino, piperidino, alkoxy (1-4C), or halogen substituents, or a pharmacologically acceptable salt of said compound.