Synthesis, characterization, and cytotoxicity of some new 5-aminopyrazole and pyrazolo[1,5-a]pyrimidine derivatives

Abstract

5-Amino-N-aryl-3-[(4-methoxyphenyl)amino]-1H-pyrazole-4-carboxamides 4a–c were synthesized by the reaction of N-(aryl)-2-cyano-3-[(4-methoxyphenyl)-amino]-3-(methylthio)acrylamides 3a–c with hydrazine hydrate in ethanol. The reaction of 5-amino-N-aryl-1H-pyrazoles 4a–c with acetylacetone 5 or 2-(4-methoxybenzylidene)malononitrile 8 yielded the pyrazolo[1,5-a]pyrimidine derivatives 7a–c and 10a–c, respectively. The structures of the synthesized compounds were established based on elemental analysis and spectral data (IR, MS, 1H-NMR, and 13C-NMR). Representative examples of the new synthesized products were screened for their in vitro cytotoxic activity against Ehrlich Ascites Carcinoma (EAC) cells.