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The β/A4‐amyloid protein (β/A4) and many synthetic fragments of this protein have proved to be very difficult to solubilize, leading to the use of relatively harsh chemical methods, most notably, formic acid. This treatment has previously been shown to cause a covalent modification of this peptide. In this study, one‐ and two‐dimensional NMR techniques are used to show that the nature of this covalent modification is formation of a formate ester to a serine residue. This finding is consistent with our previously reported kinetic studies of formic acid‐induced modification ofβ/A4 and further illustrates the potential danger of solubilizing fragments of β/A4 in formic acid. Alternative methods of solubilization are discussed.

An efficient, metal-free C-H halogenated method for the synthesis of β-halogenated carboxamides using non-corrosive NXS (X=Cl, Br) as the halogenated source and ammonium sulfocyanide (NH 4 SCN) as the additive was proposed and accomplished. Various substituted 2-oxazolines efficiently afforded the corresponding β-halogenated carboxamides via a ring-opening reaction in good yields. The characteristic features of this reaction include readily available materials, mild reaction conditions and functional groups tolerance.[a] Dr.

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