Abstract
Bromination of benzazines and benzodiazines most often gives a mixture of products. In this paper, we show that isoquinoline (1 ) may be regioselectively monobrominated in concentrated H2 SO4 using NBS or in CF3 SO3 H using N ,N ’-dibromoisocyanuric acid (DBI) to give 5-bromoisoquinoline (2 ). The bromination was found to be highly sensitive to the choice of brominating agent, acid, temperature and concentration. Quinoline, quinazoline and quinoxaline may be brominated likewise, although with the strong regioselectivity reserved to isoquinoline.
Key words
bromination - electrophilic aromatic substitution - regioselective - benzazines - benzodiazines
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