Chemical Properties
Yellow liquid
Uses
2-Bromo-4-tert-butylaniline is commonly employed in organic synthesis for the production of various compounds, including 8-Bromo-6-tert-butylquinoline. It can also be used in the production of dyes and pigments, pharmaceutical intermediates, and agrochemicals.
Preparation
4-(tert-butyl)aniline (50.0 g, 335.1 mmol), dissolved in 1.1 L of acetonitrile, was added to a flask. After cooling the mixture to 0 ℃, NBS (59.6 g, 335.1 mmol) was added and the temperature was raised to room temperature for 12 hours. After that, water (800 mL) was added, extracted with dichloromethane, and the solvent was concentrated under reduced pressure. The dichloromethane (700 mL) was added to the mixture, washed with 400 mL of 2N NaOH, filtered through a silica pad, and the solvent was concentrated under reduced pressure to obtain 2-Bromo-4-tert-butylaniline.
Hazard
H302 (33.33%): Harmful if swallowed [Warning Acute toxicity, oral]
H312 (33.33%): Harmful in contact with skin [Warning Acute toxicity, dermal]
H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]
H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]
H332 (33.33%): Harmful if inhaled [Warning Acute toxicity, inhalation]
H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]
Synthesis
Under strict light protection, 4-tert-butylaniline (10 g, 68 mmol) was dissolved in DMF (150 mL) and cooled to 0 °C. To this solution, N-bromosuccinimide (NBS, 12.1 g, 68 mmol) was slowly added and stirred continuously at 0 °C for 30 min. Subsequently, the ice bath was removed to bring the reaction mixture to room temperature and stirring was continued for 18 hours. Upon completion of the reaction, the mixture was poured into water (300 mL) and extracted with dichloromethane (CH2Cl2). The organic phases were combined, dried with anhydrous magnesium sulfate (MgSO4) and filtered. The filtrate was evaporated under reduced pressure to give a dark brown tarry crude product. Purification by column chromatography (eluent: petroleum ether/ethyl acetate=20:1) afforded the colorless oily target product 2-bromo-4-(tert-butyl)aniline (13.5 g, 87% yield). Thin-layer chromatography (TLC) analysis showed an Rf value of 0.69 (unfolding agent: petroleum ether/ethyl acetate=5:1).1H-NMR (CDCl3, 300 MHz) data were as follows: δ 7.43 (t, J=1.2 Hz, 1H), 7.14 (m, 1H), 6.72 (d, J=8.1 Hz, 1H), 3.96 (br, 2H). 1.30 (s, 9H).
References
[1] Heterocycles, 2006, vol. 68, # 12, p. 2635 - 2645
[2] Angewandte Chemie - International Edition, 2014, vol. 53, # 1, p. 178 - 183
[3] Angew. Chem., 2014, vol. 126, # 1, p. 182 - 187,6
[4] Tetrahedron Letters, 2012, vol. 53, # 39, p. 5248 - 5252
[5] Journal of Fluorine Chemistry, 2015, vol. 180, p. 33 - 39
