Synthesis and biological activity of heterocycles from chalcone

Abstract

The chalcone 3 was synthesized from 3-acetyl-4-hydroxy coumarin and 3-formylchromone by refluxing in ethanol in the presence of a catalytic amount of pyridine. 3 was converted to bipyrazoles 4a-b by treatment with hydrazine and phenylhydrazine. The compounds were screened for their antibacterial activity.

3-Formylchromones as diverse building blocks in heterocycles synthesis

“…Refluxing 3-formylchromones 1a-c with 3-acetyl-4-hydroxycoumarin (17) in ethanol containing pyridine as a basic catalyst gave 1-(4-hydroxychromen-2-one-3-yl)-3-(chromen-4-one-3-yl)-2-propen-1-ones (18) in 65-92% yields (Scheme8) [26,27].…”

3-Acetyl-4-hydroxycoumarin: Synthesis, reactions and applications

“…Siddiquiet al have described an efficient and eco-friendly methodology for the above condensation via employing Zn(L-proline) 2 as a recyclable Lewis acid catalyst in water. In each conversion, the catalyst was successfully recovered and reused several times without significant loss in yield and selectivity (Siddiqui et al, 2008.…”

A convenient synthesis of coumarinyl chalcones using HClO4–SiO2: A green approach

“…Thus, based on the above findings and in continuation of our interest for the synthesis of coumarin and chalcone derivatives (Siddiqui and Ahmed., 2013;Siddiqui et al, 2008) we report herein, the use of silica supported perchloric acid (HClO 4 -SiO 2 ) as a mild, highly efficient, and recyclable heterogeneous catalyst for the synthesis of coumarin based chalcones under thermal solvent-free conditions in excellent yields.…”