Reaktion #888

Reaktionsgleichung

1-(4-tolyloxy)-1,2-bis-(4-bromobenzoyl)ethylene

KBr

→

2,5-bis(4-Bromophenyl)-3-(p-tolyloxy)furan

Lösungsmittel

phosphorus trichloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder reflux for 3-4 hr (TLC followed)
2. 2
   SonstigeThe excess PCl3 was removed by distillation
3. 3
   Sonstigethe residue was triturated with ice/water (exothermic reaction)
4. 4
   ExtraktionThe solution was extracted with dichloromethane (75 ml)
5. 5
   Waschenthe dichloromethane layer was washed with saturated sodium bicarbonate solution, water
6. 6
   Sonstigedried (Na2 SO4)
7. 7
   SonstigeThe solvent was removed under reduced pressure
8. 8
   SonstigeThe residual solid was chromatographed over silica gel
9. 9
   SonstigeAn off white crystalline solid was obtained

Vorschrift

A solution of 5.0 g (0.01 mole) 1-(4-tolyloxy)-1,2-bis-(4-bromobenzoyl)ethylene in 10 ml phosphorus trichloride was heated under reflux for 3-4 hr (TLC followed). The excess PCl3 was removed by distillation and the residue was triturated with ice/water (exothermic reaction). The solution was extracted with dichloromethane (75 ml) and the dichloromethane layer was washed with saturated sodium bicarbonate solution, water, and dried (Na2 SO4). The solvent was removed under reduced pressure. The residual solid was chromatographed over silica gel using ether:hexane (2:8 to 1:1) as eluant. An off white crystalline solid was obtained, 2.78 g (56%), mp 92°-3° C. IR (KBr) 2923, 2851, 1560, 1506, 1467, 1390, 1209, 1072, 1066, 945, 825, 707, 486. 1H NMR (CDCl3 /35° C.) 7.69 (d, 2H, J=8.8), 7.46-7.43 (m, 6H), 7.12 (d, 2H, J=8.3), 7.0 (d, 2H, J=8.3), 6.47 (s, 1H), 2.31 (s, 3H). 13C NMR (CDCl3 /135° C.) 150.8, 150.1, 142.8, 139.3, 133.0, 131.9, 131.7, 130.3, 129.1, 128.6, 125.1, 125.0, 121.8, 120.5, 117.1, 102.7, 20.6. MS m/e 484 (M+).

Quelle