Novel antitumor acetamide, pyrrole, pyrrolopyrimidine, thiocyanate, hydrazone, pyrazole, isothiocyanate and thiophene derivatives containing a biologically active pyrazole moiety.

4-Amino-N-(1-phenyl-1H-pyrazol-5-yl)-benzenesulfonamide (sulfaphenazole) 1 was selected as strategic starting material for the synthesis of some novel acetamide 2, pyrrole 4, pyrrolo[2,3-d]pyrimidine 5, thiocyanate 6, hydrazone 7a,b pyrazole 8, isothiocyanate 9 and thiophene 12 derivatives to evaluate theantitumor activity. Compound 4 was more effective than the reference drug, doxorubicin (CAS 23214-92-8) as positive control.