Solvent-free one-pot synthesis of 4-(4-hydroxy-1,3-dithiolan-2-ylidene)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-ones

Pyrazole derivatives possess diverse chemical reactivity and broad spectrum of biological activities. A number of substituted pyrazoles are used as fungicides, insecticide, pesticides, and herbicides in the field of agriculture.1 They are used also as coloration of paints, varnishes, lacquers in the field of industry.2 Herein, we report one-pot synthesis of E and Z form of 4-(4-hydroxy-1,3-dithiolan-2-ylidene)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one derivatives 2 and 3 from the solvent-free reaction between pyrazole derivatives 1, carbon disulfide, and α-chloroacetaldehyde in the presence of triethylamine at room temperature. All synthesized compounds are stable solids whose structures were determined on the basis of their IR, 1H and 13C-NMR, and Mass spectroscopic data.

Keywords:

Solvent-free reactions , heterocyclic , one-pot , Multicomponent , 4-(4-hydroxy-1 , 3-dithiolan-2-ylidene)-5-methyl-2-phenyl-2 , 4-dihydro-3H-pyrazol-3-one.