A one-pot method for the synthesis of 3-(hetero-)aryl-1,4,2-dioxazol-5-ones

Abstract

3-R-1,4,2-dioxazol-5-ones are a class of compounds that are increasingly finding diverse uses, including as regioselective amidation reagents and as electrolyte additives that enable long cycling lifetimes in rechargeable lithium-ion batteries. Conventional methods for their synthesis tend to be slow and time-consuming, requiring isolation and thorough drying of a hydroxamic acid intermediate, followed by a separate cyclization step with N,N′-carbonyldiimidazole. Furthermore, the cyclization is typically performed in dichloromethane, an environmentally harmful solvent. This work demonstrates a new one-pot method for the synthesis of these compounds that eliminates the need for isolation of the intermediate or the use of halogenated solvents. The reaction is mainly performed using environmentally benign ethyl acetate and a relatively small amount of N,N-dimethylformamide. The reaction proceeds readily at room temperature and requires no expensive metal catalysts to function.