Reaktion #829008

Reaktionsgleichung

Trimethyl borate

3-bromofuran

BuLi

hexane

triflate

7-Methyl-4-trifluoromethanesulfonyloxycoumarin

→

4-(Furan-3-yl)-7-methylcournarin

Lösungsmittel

EtOAc

EtOAc

THF

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture stirred for 20 min.
2. 2
   workup.ADDITIONwas added
3. 3
   Temperaturthe reaction was heated
4. 4
   Temperaturto reflux for 16 h
5. 5
   Waschenthe organic phase washed with H2O (3×), brine
6. 6
   Trocknendried over MgSO4
7. 7
   Sonstigeevaporated
8. 8
   Sonstigeto give a white solid
9. 9
   Filtrationafter filtration 1.8 g (82%) of the title compound

Vorschrift

To a solution of 3-bromofuran (1.9 g, 12.7 mmol) in dry ET2O (30 mL) at -70° C. was added BuLi in hexane (1.9M, 6.7 mL, 12.7 mmol) and the resulting mixture was stirred for 20 min.. Trimethyl borate (Aldrich) (1.4 mL, 12.7 mmol) was added dropwise and the mixture stirred for 20 min.. A solution of the triflate from Step 4 in THF: H2O (24 mL: 6 mL) containing (Ph3P)4Pd (1.1 g, 0.97 mmol) was added and the reaction was heated to reflux for 16 h. The reaction mixture was cooled to r.t. and EtOAc was added and the organic phase washed with H2O (3×), brine, dried over MgSO4 and evaporated to give a white solid. A swish in EtOAc gave after filtration 1.8 g (82%) of the title compound.

Quelle