Ammonium Chloride → 4-Bromo-1-isopropoxy-2-vinylbenzene

Participants

Reaction Conditions

Reaction Steps

To a suspension of methyltriphenylphosphonium bromide (41.1 g, 115 mmol) in anhydrous THF (1.2 L) was added n-butyllithium (123 mmol, 2.5 M in hexanes) at −70° C. The mixture was stirred for a further 10 min, and then allowed to warm up to 0° C. and stirred at this temperature for 10 min. The reaction mixture is then cooled again at −50° C., and 5-bromo-2-isopropoxybenzaldehyde (20.0 g, 82.2 mmol) in solution in anhydrous THF (5 mL) was added. The mixture was stirred for 10 min, and then allowed to warm up to room temperature. An ammonium chloride solution was added and the reaction mixture was diluted with a mixture methyl t-butylether/hexane, filtered through celite, and then dried over magnesium sulfate. The solvent was removed in vacuo to afford compound AY (18.9 g) as a pale yellow oil in 95% yield. 1H NMR (CDCl3, 400 MHz): δ (ppm) 1.34 (d, J=6.0 Hz, 6H), 4.50 (sept., J=6.0 Hz, 1H), 5.27 (dd, J=11.0 and 1.1 Hz, 1H), 5.71 (dd, J=17.9 and 1.2 Hz, 1H), 6.75 (d, J=8.7 Hz, 1H), 6.97 (dd, J=17.7 and 11.2 Hz, 1H), 7.28 (dd, J=8.7 and 2.5 Hz, 1H), 7.57 (d, J=2.5 Hz, 1H).

Provenance & Evidence