Reaktion #2715

Reaktionsgleichung

2,2-dimethyl-6-bromo-chroman-4-one

2-methylthiophene

n-BuLi

hexane

→

title compound

2,2-Dimethyl-4(5-methyl-thien-2-yl)-6-bromo-chrom-3-ene

Lösungsmittel

ethyl acetate

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThis solution was added to a flask
2. 2
   workup.STIRRINGThe mixture was stirred
3. 3
   Temperaturto gradually warm to ambient temperature over 8 hours
4. 4
   workup.STIRRINGstirred for an additional 4 hours at ambient temperature
5. 5
   Waschenwashed with 10% HCl, brine (20 mL)
6. 6
   Sonstigedried
7. 7
   Sonstigethe solvent was removed by evaporation
8. 8
   SonstigeThe product was purified by chromatography on a silica gel column

Vorschrift

To a cold (-78° C.) solution of 2-methylthiophene (820 mg, 8.3 mmol) in THF (16 mL) was added n-BuLi in hexane (1.6M, 4.4 mL, 8.5 mmol). The mixture was warmed to ambient temperature and stirred for 15 minutes. This solution was added to a flask containing cold (-78° C.) solution of 2,2-dimethyl-6-bromo-chroman-4-one (1.08 g, 4.2 mmol) in THF (4 mL). The mixture was stirred and allowed to gradually warm to ambient temperature over 8 hours, and then stirred for an additional 4 hours at ambient temperature. The mixture was diluted with ethyl acetate (200 mL), washed with 10% HCl, brine (20 mL), dried and the solvent was removed by evaporation. The product was purified by chromatography on a silica gel column to afford the title compound as a colorless off.

Quelle