Synthesis, characterisation and antimicrobial screening of some new thiazolyl chromones and pyrazoles

Abstract

A series of substituted chromones and pyrazole derivatives have been synthesized from esterification of acid<strong> 1 </strong>with 2-hydroxy acetophenones<strong> 2</strong> to give compounds <strong>3</strong> which is in turn converted in to &beta;-diketones <strong>4 </strong>in presence of excess of KOH by Baker-Venkatraman transformation. Acid catalysed cyclisation of &beta;-diketones <strong>4</strong> yield a series of 2-substituted chromones <strong>5</strong>. 2-Substituted chromones <strong>5</strong> have been used to synthesise substituted pyrazole derivatives <strong>6</strong>. All the synthesised compounds have been characterised by spectral and analytical data. Chromones and pyrazoles have been evaluated for their antibacterial and antifungal activities.