N-bromobutanimide → Methyl 1-bromo-4-hydroxy-7-phenoxyisoquinoline-3-carboxylate

Participants

Reaction Steps

A mixture of 4-hydroxy-7-phenoxy-isoquinoline-3-carboxylic acid methyl ester (6.0 g, 20.32 mmol), N-bromosuccinimide (3.80 g, 21.33 mmol) and benzoyl peroxide (246 mg, 1.01 mmol) in CCl4 was refluxed for 1 h. Solid was filtered off through a plug of silica gel. Filtrate was concentrated and purified by silica chromatography, eluting with EtOAc. All fractions contain the desired product was combined and concentrated. Residue was suspended in 150 mL of (3/1) MeOH/EtOAc and was refluxed for 1 h. After cooled, solid was collected, rinsed with MeOH and dried on vacuo to provide the title compound 4.42 g (11.8 mmol) in 58% yield as a white solid. 1H NMR in CDCl3, δ ppm: 11.7 (s, 1H), 8.36 (d, 1H, J=9.2 Hz), 7.63 (d, 1H, J=2.4 Hz), 7.55-7.10 (m, 6H), 4.06 (s, 3H).

Provenance & Evidence