Reaktion #49841

Reaktionsgleichung

(MeO)3B

3-bromofuran

n-BuLi

hexane

triflate

7-Methylcoumarin-4-yl trifluoromethanesulfonate

→

title compound

Ausbeute 75.7%

4-(3-furyl)-7-methylcoumarin

Ausbeute 75.7%

Lösungsmittel

Et2O

THF

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   SonstigeThe cooling bath was removed
3. 3
   SonstigeThe solvent was evaporated
4. 4
   workup.ADDITIONH2O was added
5. 5
   Extraktionfollowed by extraction with EtOAc (3×50 ml)
6. 6
   WaschenThe combined organic phases were washed with brine
7. 7
   Trocknendried over MgSO4
8. 8
   Sonstigeevaporated
9. 9
   SonstigePurification by flash chromatography (toluene:(2-10% EtOAc))

Vorschrift

To a solution of 3-bromofuran (2.3 g, 16.1 mmol) in dry Et2O (146 ml) was added at -78° C. n-BuLi in hexane (6.42 ml, 16.1 mmol, 2.5M). The resulting solution was stirred for 20 min, then (MeO)3B (1.82 ml, 16.1 mmol) was added dropwise and after 20 min., a mixture of the triflate from Step 1 (4.50 g, 14.6 mmol) and (PPh3)4Pd (1.69 g, 1.46 mmol) in THF (60 ml) and H2O (10 ml) was added. The cooling bath was removed and the resulting mixture was heated to 65° C. for 1.75 h. The solvent was evaporated and H2O was added followed by extraction with EtOAc (3×50 ml). The combined organic phases were washed with brine, dried over MgSO4 and evaporated. Purification by flash chromatography (toluene:(2-10% EtOAc)) gave 2.5 g of the title compound, m.p. 160°-162° C.

Quelle