Synthesis and Biological Activities of 2‐Amino‐thiazole‐5‐carboxylic Acid Phenylamide Derivatives

In an attempt to develop potent and selective anti-tumor drugs, a series of novel 2-amino-thiazole-5-carboxylic acid phenylamide derivatives were designed based on the structure of dasatinib. All compounds were synthesized by a systematic combinatorial chemical approach. Biological evaluation revealed that N-(2-chloro-6-methylphenyl)-2-(2-(4-methylpiperazin-1-yl)acetamido)thiazole-5-carboxamide (6d) exhibited high antiproliferative potency on human K563 leukemia cells comparable to dasatinib. Against mammary and colon carcinoma cells 6d was either inactive (MDA-MB 231) or distinctly less active (MCF-7 and HT-29: IC(50) = 20.2 and 21.6 µM, respectively). Dasatinib showed at each cell line IC(50) < 1 µM. The results of this structure activity relationship study clearly documented that the pyrimidin-4-ylamino core of dasatinib is responsible for the anti-tumor activity against non-leukemia cell lines.