Reaktion #2710

Reaktionsgleichung

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

Compound M

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

pTSA

4-bromotoluene

t-BuLi

pentane

→

title compound

2,2-Dimethyl-4(tol-4-yl)-6-bromo-thiochrom-3-ene

Lösungsmittel

THF

ethylacetate

dichloromethane

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThis mixture was added to a flask
2. 2
   workup.STIRRINGand stirred for 16 hours at ambient temperature
3. 3
   SonstigeThe reaction was quenched
4. 4
   workup.ADDITIONby adding aq. NH4Cl
5. 5
   Extraktionthe resulting mixture was extracted with ethylacetate
6. 6
   Waschenwashed with brine
7. 7
   Sonstigedried
8. 8
   Sonstigethe solvent was removed by evaporation
9. 9
   SonstigeThe product was isolated by chromatography on silica gel
10. 10
    Temperaturheated to 50° C. for 3 hours
11. 11
    Waschenwashed with 10% NaHCO3 (5 mL), brine (5 mL)
12. 12
    Trocknendried with MgSO4
13. 13
    Sonstigethe solvent was removed by evaporation

Vorschrift

To a cold (-78° C.) solution of 4-bromotoluene (720 mg, 4.2 mmol) in THF (8 mL) was added t-BuLi in pentane (1.7M, 0.5 mL, 0.85 mmol). The mixture was warmed to ambient temperature over 30 minutes with stirring. This mixture was added to a flask containing 2,2-dimethyl-6-bromo-thiochroman-4-one (Compound M, 140 mg, 0.4 mmol) and THF (2 mL). and stirred for 16 hours at ambient temperature. The reaction was quenched by adding aq. NH4Cl, and the resulting mixture was extracted with ethylacetate, washed with brine, dried and the solvent was removed by evaporation. The product was isolated by chromatography on silica gel. The material was dissolved in dichloromethane (5 mL) and pTSA (5 mg) was added and heated to 50° C. for 3 hours. The misture was diluted with ethylacetate (20 mL), washed with 10% NaHCO3 (5 mL), brine (5 mL), dried with MgSO4 and the solvent was removed by evaporation to afford the title compound as an off.

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