5-Bromoisoquinoline is a synthetic intermediate useful for pharmaceutical synthesis.
White to yellow-brown crystals
Starting material employed in palladium-catalyzed aminomethylation and amination reactions.
[1] W. Brown, A. Gouliaev. “Bromination of Isoquinoline, Quinoline, Quinazoline and Quinoxaline in Strong Acid.” ChemInform 98 1 (2002).
To mechanically stirred concd H2SO4 (42.5 mL) at 0 °C, isoquinoline (1; 5 mL, 42.5 mmol) was slowly added. The mixture was cooled to –25 °C, and NBS (9.83 g, 55.2 mmol) was added at such a rate that the reaction temperature was kept between –25 °C and –22 °C. The mixture was stirred at -22±1 °C for 2 h and at -18±1 °C for 3h. The mixture was then worked up as described above to give 6.16 g (72%) as a slightly off-white solid after chromatography; mp 81–82 °C. The solid was further purified by sublimation (75 °C/0.2 mmHg) to give 5-Bromoisoquinoline as a white powder[1].
