反应详情

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).

1. concentrationconcentrate under reduced pressure
2. additionadd EtOAc and water to the residue
3. customSeparate the layers
4. extractionextract the aqueous material with EtOAc
5. washWash the crude
6. extractionorganic extract with water
7. dry with materialdry over MgSO4
8. filtrationfilter
9. concentrationconcentrate
10. customPurify on silica gel eluting with 7% EtOAc