Convenient Benzylic Bromination of 2‑Hydroxy-5-methylisophthalaldehyde
Nikita Žoglo1, Anton Mastitski1, Vladislav Ivanistsev1
1Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia.
Abstract:
A convenient and scalable method for the selective benzylic bromination of 2-hydroxy-5-methylisophthalaldehyde was developed, previously unreported in the literature. Direct Wohl-Ziegler conditions failed, suggesting the investigation of various protection strategies. A combination of methyl ether and geminal diacetate protecting groups gave rise to clean photochemical bromination with N-bromosuccinimide in PhCl, affording the benzyl bromide in 39% yield after recrystallization, which can be further functionalized or deprotected. This robust three-step procedure provides a practical pathway for the functionalization of isophthalaldehyde derivatives.
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