Amphiphile catalysed selective synthesis of 4-amino alkylated-1H-pyrazol-5-ol via Mannich aromatization preferred to the Knoevenagel–Michael type reaction in water

Abstract

An economic and efficient amphiphile (SDS) catalysed one pot synthesis of the aromatized 4-amino alkylated-1H-pyrazol-5-ol via a Mannich type reaction that is preferable compared to a Knoevenagel–Michael type reaction, i.e. aromatic aldehyde, secondary amine and 3-methyl-1-phenyl-5-pyrazolinone in water, has been developed. In this selective Mannich aromatization, the reaction proceeds via a micelle stabilized imine intermediate, followed by the nucleophilic addition of 3-methyl-1-phenyl-5-pyrazolinone and aromatization in water.