ZnCl₂‐Mediated Synthesis of Carboxylic Anhydrides using 2‐Acyl‐4,5‐dichloropyridazin‐3(2H)‐ones

Abstract

ZnCl₂ is an efficient catalyst for synthesis of carboxylic acid anhydride from 2‐acyl‐4,5‐dichloropyridazin‐3(2H)‐ones. Treatment of 2‐acyl‐4,5‐dichloropyridazin‐3(2H) ‐ones with ZnCl₂ (0.5 equivalents) and air in refluxing dry THF or acetonitrile gave the corresponding symmetric acid anhydrides in good to excellent yield.

Keywords:

• Carboxylic acid anhydride
• 2‐acyl‐4,5‐dichloropyridazin‐3(2H)‐one
• ZnCl₂

Acknowledgment

This work was supported by a grant from the Korea Science and Engineering Foundation (KOSEF) Grant (KRF‐2003‐015‐C00338).