591-18-4

Clear colourless to light yellow liquid

1-Bromo-3-iodobenzene is used in the preparation of 3'-bromo-2,3,4,5,6-pentaethyl-biphenyl by reacting with hex-3-yne. It is also used to prepare 1-(3'-bromophenyl)-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodec-1-ene and 1-(3'-bromophenyl)-3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooct-1-ene. Further, it is involved in the preparation of oxygen-tethered 1,6-enynes.

Cesium carbonate (Cs2CO3, 0.6 mmol, 195 mg), m-bromobenzoic acid (1, 0.3 mmol), [Ir(dF(CF3)ppy]2(dtbbpy)]PF6 (D, 6 μmol, 6.7 mg), N-iodosuccinimide (NIS, 1.5 mmol, 337.5 mg) and iodine (I2, 60 μmol, 20 mol%). The tubes were evacuated and displaced three times with argon, followed by the addition of 3 mL of dry 1,2-dichloroethane (DCE) through a syringe under argon protection. The test tube was sealed with Parafilm? and placed in an oil bath equipped with a contact thermometer. The reaction system was irradiated with a 6 x 5 W blue LED lamp (λmax = 455 nm) at 50 °C for 24 to 36 hours. Upon completion of the reaction, the mixture was filtered through a 2 cm thick pad of silica gel and the silica gel was washed with dichloromethane (DCM, 50 mL). The filtrates were combined and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast column chromatography on silica gel to afford the target product 1-bromo-3-iodobenzene (2). (Note: The reaction is extremely sensitive to moisture, and the product yield was significantly reduced to less than 5% when 0.01 equivalents of water was added to the system.)

[1] Synlett, 2018, vol. 29, # 12, p. 1572 - 1577
[2] Patent: WO2015/68159, 2015, A2. Location in patent: Paragraph 00215-00216