Reacción #2271675

Ecuación de reacción

water

1,3-dibromopropane

3-hydroxy-4-methoxybenzophenone

sodium hydride

dimethylformamide

→

3-(3-bromopropoxy-4-methoxyphenyl]phenylmethanone

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroAt the end of the reaction
2. 2
   Extracciónextracted with ethyl acetate (400 ml)
3. 3
   LavadoThe ethyl acetate solution was washed with water, brine
4. 4
   Secadodried over anhydrous MgSO4
5. 5
   OtroThe solvent was removed
6. 6
   Otrothe crude oil was purified by flash chromatography over a silica gel column (SiO2, 85 g: eluted with 3:1 hexane:dichloromethane, 1.6 l; 3:7 hexane:dichloromethane, 1.4 l)
7. 7
   OtroThe pure product thus obtained
8. 8
   OtroRecrystallization twice from isopropyl ether (500 ml)

Procedimiento

A solution of 3-hydroxy-4-methoxybenzophenone (4.6 g, 20 mmol) in dimethylformamide, (35 ml) was treated with sodium hydride (600 mg, 25 Mmol) at 0° C. for 20 minutes, then 1,3-dibromopropane (5 g, 24.7 mmol) was added in one portion. The mixture was heated at 90° C. for 1 hour, and then stirred at room temperature for 2 hours. At the end of the reaction, the mixture was poured into water (500 ml) and extracted with ethyl acetate (400 ml). The ethyl acetate solution was washed with water, brine, and dried over anhydrous MgSO4. The solvent was removed and the crude oil was purified by flash chromatography over a silica gel column (SiO2, 85 g: eluted with 3:1 hexane:dichloromethane, 1.6 l; 3:7 hexane:dichloromethane, 1.4 l). The pure product thus obtained weighed 4.67 g, (66%) as an oil. Recrystallization twice from isopropyl ether (500 ml) gave analytically pure 3-(3-bromopropoxy-4-methoxyphenyl]phenylmethanone (2.42 g), m.p.=81°-83° C.

Fuente