反応 #2704

反応方程式

3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone

Compound A

3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone

2-methylthiophene

n-BuLi

→

title compound

収率 62.3%

1-(5-Methyl-thien-2-yl) 3,4-dihydro-4,4-dimethyl-7-bromo-naphthalene

収率 62.3%

溶媒

THF

ether ethylacetate

THF

反応条件

後処理

1. 1
   その他transferred to a cold (-78° C.) flask
2. 2
   洗浄washed with water (10 mL), brine (10 mL)
3. 3
   乾燥dried with MgSO4
4. 4
   その他the solvent was removed by evaporation
5. 5
   workup.DISSOLUTIONThe crude material was dissolved in dichloroethane (20 mL)
6. 6
   workup.ADDITIONpTSA (40 mg) was added
7. 7
   workup.STIRRINGThe mixture was stirred at ambient temperature for 16 hours and at 50° C. for 4 hours
8. 8
   workup.ADDITIONThe reaction mixture was diluted with ether (150 mL)
9. 9
   洗浄washed with aqueous 10% NaHCO3 (10 mL), brine (10 mL)
10. 10
    乾燥dried with MgSO4
11. 11
    その他Purification by chromatography on silica gel

実験手順

To a cold (-78° C.) solution of 2-methylthiophene (800 mg, 8.1 mmol) in THF (10 mL) was added n-BuLi (1.6M solution in hexane, 5 mL). The mixture was stirred for 1.5 hours and transferred to a cold (-78° C.) flask containing 3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone (Compound A, 1.63 g, 6.5 mmol), in THF (15 mL). The mixture was gradually warmed to 0° C. The reaction mixture was diluted with ether:ethylacetate (1:1, 80 mL), washed with water (10 mL), brine (10 mL), dried with MgSO4 and the solvent was removed by evaporation. The crude material was dissolved in dichloroethane (20 mL) and pTSA (40 mg) was added. The mixture was stirred at ambient temperature for 16 hours and at 50° C. for 4 hours. The reaction mixture was diluted with ether (150 mL), washed with aqueous 10% NaHCO3 (10 mL), brine (10 mL) and dried with MgSO4. Purification by chromatography on silica gel gave 1.35 g of the title compound as a white solid.

出典