New, Convenient, One-Pot Method for the Synthesis of Thiazolyl-pyrazolones from Dehydroacetic Acid Derivative via a Multicomponent Approach

Abstract

A convenient one-pot method for the synthesis of thiazolyl-pyrazolones was described in excellent yields. Reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one with thiosemicarbazide and ethyl 2-(2-arylhydrazono)-3-oxobutanoates in anhydrous ethanol under reflux conditions afforded the corresponding 4-(2-arylhydrazono)-1-(4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)thiazol-2-yl)-3-methyl-1H-pyrazol-5(4H)-one in good yields. The structures of newly synthesized compounds were established on the basis of elemental analysis, infrared, ¹H NMR, and mass spectroscopic studies.

GRAPHICAL ABSTRACT

Keywords:

• Aromatic primary amine
• 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one
• multicomponent reactions
• one-pot synthesis
• thiazolyl-pyrazolone
• thiosemicarbazide

ACKNOWLEDGMENT

The authors are thankful to the director, National Institute of Technology, Warangal, A.P., India, for providing financial support and facilities.