Reaktion #343967

Reaktionsgleichung

iodine

2- (1,1-dimethyldecyl)-4-bromo anisole

magnesium

methyl 6-bromo-2-naphthoate

→

6-[3-(1,1-dimethyldecyl)-4-methoxyphenyl]-2-naphthoic acid

Lösungsmittel

THF

THF

THF

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture is slightly heated at the beginning of the addition until the reaction of formation of the Grignard
2. 2
   workup.ADDITIONThen the remainder of the solution containing the brominated derivative
3. 3
   workup.ADDITIONis added in a manner
4. 4
   Temperaturto maintain a regular reflux
5. 5
   workup.ADDITIONOnce the addition
6. 6
   Temperaturcooled to ambient temperature
7. 7
   workup.STIRRINGThe mixture is stirred for 30 minutes at ambient temperature
8. 8
   workup.STIRRINGThe mixture is stirred for 3 hours at ambient temperature at which
9. 9
   workup.ADDITIONare added
10. 10
    Extraktionthe residue is extracted with dichloromethane
11. 11
    Sonstigedried
12. 12
    Sonstigethe solvent evaporated
13. 13
    SonstigeThe residue is purified by passage through a silica column (eluant: mixture of 60% dichlorlmethane and 40% hexane)
14. 14
    SonstigeOn evaporation
15. 15
    Sonstigea solid is obtained which
16. 16
    Sonstigeis recrystallized twice in hexane

Vorschrift

A solution of 16 g (45 mmol) of 2- (1,1-dimethyldecyl)-4-bromo anisole in 60 ml of THF is slowly added to 1.3 g (54 mmol) of magnesium and a crystal of iodine. The mixture is slightly heated at the beginning of the addition until the reaction of formation of the Grignard is initiated. Then the remainder of the solution containing the brominated derivative is added in a manner to maintain a regular reflux. Once the addition is complete, the mixture is stirred for 30 minutes at 50° C. and then cooled to ambient temperature. 7.4 g (54 mmol) of zinc chloride in solution in 50 ml of THF are added. The mixture is stirred for 30 minutes at ambient temperature, 6.6 g (25 mmol) of methyl 6-bromo-2-naphthoate are added and then 175 mg of NiCl2 /DPPE complex. The mixture is stirred for 3 hours at ambient temperature at which point 250 ml of water are added. The THF is eva-porated under reduced pressure and the residue is extracted with dichloromethane, dried and the solvent evaporated. The residue is purified by passage through a silica column (eluant: mixture of 60% dichlorlmethane and 40% hexane). On evaporation, a solid is obtained which is recrystallized twice in hexane to give the methyl ester of 6-[3-(1,1-dimethyldecyl)-4-methoxyphenyl]-2-naphthoic acid: 705 g (61%). Melting point: 92° C.

Quelle