Thioxanthenone antitumor agents

A compound of formula ##STR11## wherein n is 2 or 3;

• R.sup.1 and R.sup.2 are independently lower-alkyl;
• Q is CH.sub.2 N(R.sup.4)SO.sub.2 R.sup.7 ;
• R.sup.4 is hydrogen, lower-alkyl or Ar;
• R.sup.7 is lower-alkyl, or Ar;
• R.sup.8 is hydrogen, lower-alkyl, lower-alkoxy, or hydroxy;
• and
• Ar is phenyl or phenyl substituted with methyl, methoxyl, hydroxy, halogen or nitro, with the proviso that when n is 2, R.sup.1 and R.sup.2 are ethyl, R.sup.8 is hydrogen and Q is CH.sub.2 NHSO.sub.2 Ar, the Ar group cannot be 4-monosubstituted by methyl or halogen;
• or a pharmaceutically acceptable acid-addition salt or solvate thereof.