تفاعل #888

معادلة التفاعل

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

KBr

→

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

المذيبات

phosphorus trichloride

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةunder reflux for 3-4 hr (TLC followed)
2. 2
   أخرىThe excess PCl3 was removed by distillation
3. 3
   أخرىthe residue was triturated with ice/water (exothermic reaction)
4. 4
   استخلاصThe solution was extracted with dichloromethane (75 ml)
5. 5
   غسيلthe dichloromethane layer was washed with saturated sodium bicarbonate solution, water
6. 6
   أخرىdried (Na2 SO4)
7. 7
   أخرىThe solvent was removed under reduced pressure
8. 8
   أخرىThe residual solid was chromatographed over silica gel
9. 9
   أخرىAn off white crystalline solid was obtained

الإجراء التجريبي

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+).

المصدر