Reacción #1596944

Ecuación de reacción

ethanol

bismuth(III) bromide

4-benzyloxy-3-fluorobenzaldehyde

2-vinylpentan-1-ol

→

2-(4-benzyloxy-3-fluorophenyl)-4-bromo-5-propyltetrahydropyran

Disolventes

chlorobutane

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroInsoluble constituents are separated off
2. 2
   Filtraciónthe mixture is filtered absorptively (SiO2, CH2Cl2)
3. 3
   ConcentraciónThe filtrate is concentrated to dryness
4. 4
   Otrothe residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1)
5. 5
   OtroThe oil obtained
6. 6
   OtroThe crystals which deposit are collected
7. 7
   Otrorecrystallised again from n-heptane

Procedimiento

188.0 g (0.79 mol) of 4-benzyloxy-3-fluorobenzaldehyde are initially introduced in 1000 ml of dichloromethane at 0° C. together with 90.0 g (0.79 mol) of 2-vinylpentan-1-ol. 176.0 g (0.39 mol) of bismuth(III) bromide are added in portions, and the mixture is stirred at room temperature for 19 h. Insoluble constituents are separated off, and the mixture is filtered absorptively (SiO2, CH2Cl2). The filtrate is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1). The oil obtained is taken up in chlorobutane, and the solution is added dropwise to cold ethanol. The crystals which deposit are collected and recrystallised again from n-heptane. In this way, 2-(4-benzyloxy-3-fluorophenyl)-4-bromo-5-propyltetrahydropyran is obtained as a yellowish solid.

Fuente