2,4-disubstituted thiazoles .2. A novel class of antitumor agents, synthesis and biological evaluation

A series of 2,4-disubstituted thiazole derivatives bearing N-n-butyl or N-cyclohexylthioureido synthon at position 2 and N-substituted thiosemicarbazone moiety at position 4 have been synthesized and tested for antitumor activity using the National Cancer Institute's in-vitro-disease-oriented antitumor screen. All of the tested compounds showed antineoplastic activity at concentrations less than 100 mu M. Compounds 7, 9, 15 and 17 in particular showed activity with GI(50) (mean-graph midpoint) of 17.8, 8.5, 9.5 and 7.4 mu M, respectively. The detailed syntheses, spectroscopic and biological data are discussed.