A new and efficient route toward the preparation of diazo ketones using cyanuric chloride and diazomethane

A new method for the preparation of diazo ketones has been developed. 2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride) has been found to be an excellent coupling reagent allowing for the efficient transfer of diazomethane to a carboxylic acid. Preparation of diazo ketones using carboxylic acids and triazine reagents is considerably more convenient than classical diazo transfer protocols because water does not have to be stringently removed and the entire procedure can be carried out in one-pot. Electron deficient and neutral aryl carboxylic acids were found to give better results than electron rich or aliphatic carboxylic acids. (C) 2000 Elsevier Science Ltd. All rights reserved.