Efficient solvent- and catalyst-free one-pot synthesis of novel trifluoromethylated pyrazole derivatives

A novel and efficient one-pot, three-component reaction was developed for the synthesis of 2-phenyl-4-((arylamino)methylene)-5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one derivatives. The reaction proceeds via the condensation of 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one, aniline derivatives, and trimethyl orthoformate under solvent-free conditions at 110 °C. This green protocol integrates multiple pharmacophores, offering potential for biological applications. Key advantages include operational simplicity, high yields (80%–92%), and the absence of catalysts and solvents. IR,1H,1³C, 19F NMR, mass spectrometry, and elemental analysis confirmed product structures.