Réaction #888

Équation de réaction

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

KBr

→

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

Solvants

phosphorus trichloride

Conditions de réaction

Traitement

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

Mode opératoire

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+).

Source