Jeum-Jong Kim

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.

Convenient Preparation of O‐Alkylhydroxamic Acids Using 2‐Acylpyridazin‐3(2H)‐ones

Abstract Treatment of O‐alkylhydroxylamine hydrochlorides with 2‐acyl‐4,5‐dichloropyridazin‐3(2H)‐ones in the presence of triethylamine or Amberlite® IRA‐67 in acetonitrile gave corresponding O‐alkylhydroxamic acid derivatives in excellent yields. This is an efficient, convenient, and eco‐friendly method.