Reaktion #91600

Reaktionsgleichung

cyclohexylmethyl 5-bromofuran-2-carboxylate

ethynylcyclohexane

→

cyclohexylmethyl 5-(cyclohexylethynyl)furan-2-carboxylate

Lösungsmittel

Et3N

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas degassed
2. 2
   Sonstigeby bubbling Ar
3. 3
   Sonstigethe reaction mixture was degassed
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   SonstigeThe residue was partitioned between hexanes and aqueous NH4Cl (25%) and aqueous layer
6. 6
   Extraktionwas extracted twice with hexanes
7. 7
   WaschenCombined organic layers were washed with brine
8. 8
   workup.ADDITIONtreated with activated charcoal
9. 9
   Trocknendried over anhydrous MgSO4
10. 10
    EinengenConcentration under reduced pressure

Vorschrift

A mixture of cyclohexylmethyl 5-bromofuran-2-carboxylate (0.63 g, 2.19 mmol) and ethynylcyclohexane (0.32 g, 2.96 mmol) in Et3N (10 mL) was degassed by bubbling Ar. CuI (0.023 g, 0.119 mmol) and PdCl2(Ph3P)2 (0.0412 g, 0.0587 mmol) were added and the reaction mixture was degassed by alternating vac/Ar three 3 times. The reaction mixture was stirred at +70° C. under Ar overnight and concentrated under reduced pressure. The residue was partitioned between hexanes and aqueous NH4Cl (25%) and aqueous layer was extracted twice with hexanes. Combined organic layers were washed with brine, treated with activated charcoal and dried over anhydrous MgSO4. Concentration under reduced pressure gave cyclohexylmethyl 5-(cyclohexylethynyl)furan-2-carboxylate as an orange solid which was used directly in the next step without additional purification. Yield (0.75 g, quant.); 1H NMR (400 MHz, CDCl3) δ 7.10 (d, J=3.9 Hz, 1H), 6.50 (d, J=3.9 Hz, 1H), 4.10 (d, J=6.4 Hz, 2H), 1.56-2.66 (m, 1H), 1.63-1.84 (m, 9H), 1.42-1.60 (m, 4H), 1.10-1.40 (m, 6H), 0.96-1.10 (m, 2H).

Quelle