O- and N-substituted derivatives of planetol as valuable bioactive compounds

Abstract

The compounds bearing sulfamoyl and acetamoyl groups have been found to show various biological activities. In the present research work, a series of O- and N-substituted derivatives were synthesized, starting with planetol (1). First N-methyl-4-hydroxyanilinium sulfate (1; planetol or metol) was treated with different aryl sulfonyl chlorides (2a-i) using aq. sodium carbonate solution as reaction medium to yield N-substituted derivatives 3a-i. The electrophile, N-(2,3-dihydro-1,4-benzodioxin-6-yl)-2-bromoacetamide (5) was prepared by the reaction of 2,3-dihydro-1,4-benzodioxin-6-amine (4) and 2-bromoacetylbromide in a weak basic aqueous medium. The target O-substituted molecules 6a-i, were synthesized by gearing up the electrophile 5, with the molecules 3a-i, in a polar aprotic solvent using LiH as an activator. The proposed structures of all the synthesized molecules were corroborated by IR,1H NMR and EIMS spectral data. The in vitro enzyme inhibition and antibacterial studies rendered the synthesized molecules as better cholinesterase inhibitors and moderately better antibacterial agents. To explore the binding modes of the synthesized compounds, all of them were computationally docked against the active sites of acetyl cholinesterase (AChE), butyryl cholinesterase (BChE) and lipoxygenase (LOX). The compounds showed significant interactions and good correlation with the experimental data.