2-bromoaniline (>98.0%, TCI America)

3,3-dimethylacryloyl chloride (97%, Acros Organics)

Pyridine (99%, Extra Dry, Acros Organics)

Diethyl ether (99.5%, Extra Dry, Acros Organics)

Hydrochloric acid (36.5-38%, VWR Chemicals)

Diethyl ether (Fisher Scientific)

Magnesium sulfate (EMD Millipore)

NaHCO₃ (Amresco)

Brine (Ward’s Science)

The reaction was performed under an atmosphere of nitrogen. In a 100 mL round bottom flask, 2-bromoaniline (2.11 g, 12.2 mmol) was dissolved in dry diethyl ether (36 mL), followed by dry pyridine (1.79 mL, 22.2 mmol). The reaction was cooled to 0°C and 3,3-dimethylacryloyl chloride (1.33 mL, 12.0 mmol) was slowly added to the mixture, over 10 minutes, as a white solid formed. After 75 minutes at room temperature, diethyl ether (60 mL) was added to the resulting mixture and extracted with 3 M HCl (30 mL X 3), sat. aq. NaHCO₃ (30 mL), and brine (30 mL). The organic layer was dried over MgSO₄, filtered, and concentrated in vacuo to afford the title product (2.16 g, 71%) as a white solid.

The product contained a small amount of impurity as seen in the ¹ H NMR spectrum, which was removed via flash column chromatography.  

¹ H NMR (400 MHz, CDCl₃): δ 8.42 (d, J = 8.0 Hz, 1H), 7.52 (dd, J = 8.4, 1.6 Hz, 2H), 7.30 (td, J = 8.0, 1.6 Hz, 1H), 6.95 (td, J =  7.6, 1.6 Hz, 1H), 5.77 (t, J = 1.2 Hz, 1H), 2.24 (d, J = 1.2 Hz, 3H), 1.94 (d, J = 1.2 Hz, 3H)

¹³ C NMR (100 MHz, CDCl₃): δ 164.72, 154.49, 136.08, 132.14, 128.29, 124.71, 121.65, 118.50, 32.76, 27.47, 20.09

mp = 95.3°C – 97.6°C

R_f = 0.81 (1:1 EtOAc/Hex)

Evan, D., et al. J. Am. Chem. Soc. 2008, 130, 48, 16295 – 16309.