Synthesis of new cis- and trans-3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl) chromanones using a hypervalent iodine oxidation approach

Abstract

Oxidation of 2′-hydroxychalcone analogues of pyrazole 1 using iodobenzene diacetate in KOHMeOH leads to the formation of cis-3-hydroxy-2-(1- phenyl-3-aryl-4-pyrazolyl) chromanone dimethylacetals 2. The hydrolysis of the dimethylacetals 2 affords either trans-3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl) chromanones 3 and cis-3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl) chromanones 4 depending upon the hydrolytic conditions in good yields. Their 1H NMR, IR and mass spectra confirmed the structures of the compounds 2, 3 and 4. ©ARKAT.