Efficient conjugate addition of 3-methyl-5-pyrazolones to chalcones in water extract rice straw ash (WERSA)

Abstract

Conjugate addition of 5-methyl-pyrazolones to chalcone has been described with Water Extract Rice Straw Ash (WERSA) as the reaction medium. Various chalcones have been used as Michael acceptors against 5-methyl-pyrazolones. The products have been isolated in analytically pure form by simple filtration in good to excellent yields under green reaction conditions with good substrate scope. This general eco-friendly method uses waste material for organic transformation. The synthesised compounds could be further utilised for the synthesis of bioactive molecules and pharmaceutical products.