A High-Yield Preparative-Scale Method for 2-Bromofuran

Abstract Recently1 we reported excellent preparative methods for 2-bromothiophene involving addition of hydrogen peroxide to a mixture of concentrated aqueous hydrogen bromide, thiophene and diethyl ether or addition of a solution of bromine in concentrated aqueous hydrogen bromide to a mixture of thiophen, diethyl ether and aqueous hydrogen bromide. Similar procedures with furan gave intractable mixtures of unindentified products. A literature search afforded only two procedures2,3 for the direct bromination of furan, viz. the reactions of furan with hexabromocyclopentadiene and the bromine-dioxan complex. Although good yields are reported, these methods do not seem attractive for the preparation of 2-bromofuran in sizable amounts. We have applied the well-established reaction of lithium compounds with elemental bromine to prepare 2-bromofuran.