4-Diazomethyl-7-Methoxycoumarin as a New Type of Stable Aryldiazomethane Reagent

Abstract

Diazoalkanes have been widely used as versatile alkylating agents. One of the principal advantages of using diazoalkane is that no side reaction product other than gaseous nitrogen is produced during alkylation process. However, most diazoalkanes suffer from the fact that they are unstable, sometimes explosive, and are not available in pure state. They have to be only used in the solutions prepared from appropriate precursors just before use. Thus, only a few compounds have been developed so far as solid diazoalkane reagents¹ of practical value which are suitable for labeling acidic substances for analytical and biochemical purposes. We have now obtained 4-diazomethyl-7-methoxycoumarin 4 as a new type of crystalline aryldiazomethane having excellent purity and stability as well as enough reactivity to produce a fluorophore with carboxylic or sulfonic acid by esterification.