Réaction #10502

Équation de réaction

5-bromo-2-vinyl-benzooxazole

4-cyanophenylboronic acid

tri-tert-butylphosphine

tetrahydrofuran

→

4-(2-vinyl-benzooxazol-5-yl)-benzonitrile

Rendement 78.0%

Solvants

hexane

Conditions de réaction

Traitement

1. 1
   TempératureIt was then heated at 65° C. for 0.5 hour
2. 2
   Températurecooled
3. 3
   Filtrationfiltered
4. 4
   Autreto remove particulates
5. 5
   Autrepartitioned between 80 mL of water
6. 6
   workup.ADDITIONa mixture of 30 mL of ethyl acetate and 10 mL of hexane
7. 7
   AutreThe organic phase was collected
8. 8
   Séchagedried over Na2SO4
9. 9
   Autrepurified by flash chromatography on silica gel (eluting with 1:1 hexane:dichloromethane)

Mode opératoire

A mixture of 224 mg (1 mmol) of 5-bromo-2-vinyl-benzooxazole, 191 mg (1.3 mmol) of 4-cyanophenylboronic acid, 55 mg (0.03 mmol) of tris-(dibenzylidineacetone)dipalladium (0) (CAS #52409-22-0), 0.2 mL (0.06 mmol) of a 10% solution of tri-tert-butylphosphine in hexane, and 1.5 mL of tetrahydrofuran was stirred at 23° C. for 24 hours. It was then heated at 65° C. for 0.5 hour, then cooled. The mixture was suction filtered to remove particulates, then partitioned between 80 mL of water and a mixture of 30 mL of ethyl acetate and 10 mL of hexane. The organic phase was collected, dried over Na2SO4, and purified by flash chromatography on silica gel (eluting with 1:1 hexane:dichloromethane) to give 4-(2-vinyl-benzooxazol-5-yl)-benzonitrile (192 mg, 78%) as a white solid: mp 143–144° C.; 1H NMR (300 MHz, CDCl3) δ 7.90 (d, J=1.8 Hz, 1 H), 7.76 (d, J=8.4 Hz, 2 H), 7.70 (d, J=8.4 Hz, 2 H), 7.62 (d, J=7.5 Hz, 1 H), 7.55 (dd, J=7.5, 1.8 Hz, 1 H), 6.79 (dd, J=17.4, 10.5 Hz, 1 H), 6.52 (d, J=17.4 Hz, 1 H), 5.91 (d, J=10.5 Hz, 1 H); Mass spectrum: [M+H]+ 247.1.

Source