Synthesis, Crystal Structure, and Antiproliferative Activity of Novel 7-Arylaminopyrazolo[1,5-a]pyrimidine Derivatives Containing the Hydrazone Moiety

A series of novel 7-arylaminopyrazolo[1,5-a]pyrimidine derivatives containing the hydrazone moiety has been synthesized by a five-step procedure including cyclization, chlorination, amination, hydrazinolysis, and condensation. Structures of the products have been characterized by IR, H-1 NMR and MS spectra, and single-crystal X-ray diffraction. The bioassay results indicate most of the compounds as potentially antiproliferation agents against A549 and HT-29 cell lines. Among those, compounds 6e and 6f exhibit remarkable inhibitory activity against HT-29 cell lines, that are comparable with that of the positive control sorafenib. Preliminary structure-activity relationship is considered.