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Published on: May 27, 2015
C-6 regioselective bromination of methyl indolyl-3-acetate
Oscar R Suárez-Castillo1, Myriam Meléndez-Rodríguez, Lidia Beiza-Granados
1Area Académica de Química, Universidad Autónoma del Estado de Hidalgo, Mineral de la Reforma, Hidalgo, 42184 México. osuarez@uaeh.edu.mx
Abstract:
An efficient route to natural occurring methyl 6-bromoindolyl-3-acetate 1c from methyl indolyl-3-acetate 3 was achieved in 3 steps and 68% overall yield. Thus, in order to regioselectively brominate 3 at the C6-position, introduction of electron withdrawing substituents at N1 and C8 was affected to give intermediate 4 in 82% yield. Bromination of 4 with 8 equiv of bromine in CCl4 and washings with aqueous Na2SO3 gave 5 in 86% yield, which was N- and C-decarbomethoxylated by treatment with NaCN in DMSO, affording 1c in 97% yield. The regioselectivity of bromination was evidenced by NMR spectroscopy and X- ray diffraction analysis.
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