Synthesis and Reactivity of α-Halogenated, C-Protected β-Enamino Acids

C-Protected β-enamino acids (I) reacted with one equivalent of Nhalosuccinimides (NXS) to furnish their α-halogenated derivatives (II). These compounds were then successfully transformed into halogenated uracil derivatives (III) through reaction with triphosgene, followed by 5-membered ring-opening under acidic conditions.