Efficient synthesis of new biheterocyclic 1-(5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazol-1-yl)-3-(6-trifluoro methylpyrimidin-4-yl)-propan-1-ones

Several new 1-(5-hydroxy-5-trifluoromethyl-1H-pyrazol-1-yl)-3-(6-trifluoromethyl pyrimidin-4-yl)-propan-1-ones were prepared by cyclocondensation between two different 3-[6-trifluoromethyl-2-(substituted)pyrimidin-4-yl]propanoylhydrazides derived from levulinic acid and versatile 1,1,1-trifluoro-4-alkoxy-3-alken-2-ones. The structure of new propionyl-spaced bis trifluoromethylated biheterocycles was characterized based on 1H and 13C nuclear magnetic resonance spectroscopy and mass spectrometry data.