# Mechanochemical synthesis of bis-benzoquinonylmethanes promoted by sulfonic acid-functionalized chitosan

## TL;DR

A new eco-friendly method uses chitosan to make bis-benzoquinonylmethanes efficiently without solvents.

## Contribution

A sustainable, solvent-free mechanochemical synthesis using sulfonic acid-functionalized chitosan as a recyclable promoter.

## Key findings

- Sulfonated chitosan enables high-yield synthesis of bis-lawsones under solvent-free conditions.
- The method is broadly tolerant to aryl-substituted aldehydes and is recyclable over multiple cycles.
- The protocol is scalable and maintains efficiency without solvents.

## Abstract

A sustainable mechanochemical method for synthesizing functionalized bis-lawsones from 2-hydroxynaphthalene-1,4-dione and aldehydes under solvent-free conditions is described. Sulfonated chitosan acts as both a biodegradable grinding auxiliary and a solid acid promoter, enabling high yields, broad tolerance to aryl-substituted aldehydes, and recyclability over multiple cycles with minimal loss of activity. The protocol is readily scalable without compromising efficiency.

Mechanochemical synthesis of bis-benzoquinonylmethanes using a recyclable sulfonic acid-functionalized chitosan as a promoter under solvent-free conditions, affording high yields with broad substrate scope and a sustainable, scalable protocol..