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.