Reaction #217530

Reaction equation

3-(trifluoromethyl)-benzaldehyde

2-(3-bromophenyl)-1,3-dioxolane

2-(3-bromophenyl)-1,3-dioxolane

magnesium

NH4Cl

→

(3-(1,3-dioxolan-2-yl)phenyl)[3-(trifluoromethyl)phenyl]-methan-1-ol

Solvents

THF

THF

THF

Conditions

Workup

1. 1
   workup.WAITat 50-60° C. for 20 hours
2. 2
   TemperatureAfter the mixture is cooled
3. 3
   workup.STIRRINGthe reaction is stirred at room temp for 24 hours
4. 4
   workup.STIRRINGstirred for 30 minutes
5. 5
   OtherThe organic layer is separated
6. 6
   Extractionthe aqueous layer is extracted with ethyl acetate (2×100 mL)
7. 7
   Dryingdried over anhydrous Na2SO4
8. 8
   OtherThe solvent is removed
9. 9
   Otherthe residue is purified by column chromatography on silica gel
10. 10
    WashEluting with ethyl acetate/hexanes (20:80)

Procedure

A 1.0 mL aliquot of 2-(3-bromophenyl)-1,3-dioxolane is added into magnesium (610 mg; 25 mmol) and THF (5 mL) under Argon. After the reaction is started, the residue of 2-(3-bromophenyl)-1,3-dioxolane (total: 5.73 g; 25 mmol) in THF (20 mL) is added dropwise into the reaction mixture. The resulting solution is stirred at room temp for six hours, and then at 50-60° C. for 20 hours. After the mixture is cooled, a solution of 3-(trifluoromethyl)-benzaldehyde (4.35 g; 25 mmol) in THF (20 mL) is added dropwise and the reaction is stirred at room temp for 24 hours. A saturated solution of NH4Cl (50 mL) is added and stirred for 30 minutes. The organic layer is separated and the aqueous layer is extracted with ethyl acetate (2×100 mL). The organic layers are combined and dried over anhydrous Na2SO4. The solvent is removed and the residue is purified by column chromatography on silica gel. Eluting with ethyl acetate/hexanes (20:80) provide a colorless oil (3.23 g; 40%) as (3-(1,3-dioxolan-2-yl)phenyl)[3-(trifluoromethyl)phenyl]-methan-1-ol: MS 307.0 (M−17).

Source