Synthesis of some new 1-(6-fluorobenzothiazol-2-yl)- 3-(4-fluoro- phenyl)-5-arylpyrazolines and their iodine(III) mediated oxidation to corresponding pyra-zoles

Abstract

The reaction of fluorinated chalcones 2 and 6-fluorobenzothiazol-2-ylhydrazine 1 in presence of catalytic amount of glacial acetic acid in refluxing ethanol yields 1-(6-fluorobenzothiazol-2-yl)-3- (4-fluorophenyl)-5-arylpyrazolines 3, which undergo facile oxidation to the corresponding pyrazoles 4 in good yield using iodobenzene diacetate (IBD). The structures of the synthesized compounds have been established on the basis of their elemental analysis, MS and ¹H and ¹³C NMR spectroscopy.