Acetonitrile → 2-(4-Bromo-phenyl)-5-methyl-4-vinyl-oxazole

Beteiligte Stoffe

Reaktionsschritte

Add 2,8,9-trimethyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane (3.17 g, 14.7 mmol) as a solution using acetonitrile (10 mL) to a solution of 2-(4-bromo-phenyl)-4-(2-iodo-ethyl)-5-methyl-oxazole (See Intermediate 30) (4.38 g, 11.1 mmol) in 2.8:1 acetonitrile:THF (190 mL). After 4 hrs, concentrate under reduced pressure and add EtOAc and water to the residue. Separate the layers and extract the aqueous material with EtOAc. Wash the crude organic extract with water, dry over MgSO4, filter and concentrate. Purify on silica gel eluting with 7% EtOAc to give 2-(4-bromo-phenyl)-5-methyl-4-vinyl-oxazole (2.31 g, 83%): 1H NMR (400 Hz): (CDCl3) δ 7.89 (d, 2H, J=8 Hz), 7.57 (d, 2H, J=8 Hz), 6.54 (dd, 1H, J=17, 11 Hz), 5.93 (dd, 1H, J=17, 2 Hz), 5.29 (dd, 1H, J=11, 2 Hz), 2.40 (s, 3H).

Herkunft & Nachweise