Two literature procedures for selective bromination of 2-nitrobenzaldehyde using N-bromosuccinimide (NBS) or NaBr-NaIO 4 in sulfuric acid were examined. In contrast to the reports that 4-bromo-2-nitrobenzaldehyde is formed as a single product in good yield, reactions using NBS gave a number of isomeric mono- and dibrominated products identified by spectroscopical methods and by sodium borohydride reduction to the corresponding benzyl alcohol, and reactions ...
