Chemoselective microwave-assisted amidination was successfully developed to alternatively synthesize 1H-pyrazol-5-yl-N,N-dimethyl-formamidine and pyrazolyl-2-azadiene two classes compounds. All of the starting materials and resulting products were tested against NCI-H226, NPC-TW01, and Jurkat cancer cell lines to evaluate their difference in antiproliferative activities for realizing the structure activity relationship study.
Following the SAR result, 1H-pyrazol-5-yl-N,N-dimethylformamidine compounds 2b, 2c and 2d possessed the best potent with IC50 values in low micromolar range. On the other hand, we found that the formyl group at C-4 position and the grafted amidinyl group in the main core of pyrazolic molecule were necessary for the inhibitory activity.