Reaktion #1005976

Reaktionsgleichung

2,2-dimethyl-4-oxo-thiochroman-6-yl trifluoromethanesulfonate

trimethylsilylacetylene

→

2,2-dimethyl-6-trimethylsilanylethynyl-thioc-hroman-4-one

Ausbeute 91.0%

Lösungsmittel

Et3N

DMF

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled to room temperature
2. 2
   ExtraktionExtraction with EtOAc
3. 3
   Waschenby washing the combined organic layers with H2O and saturated aqueous NaCl
4. 4
   Trocknendrying over MgSO4

Vorschrift

A solution of 2,2-dimethyl-4-oxo-thiochroman-6-yl trifluoromethanesulfonate (2.88 g, 8.50 mmol) in 10 mL Et3N and 20.0 mL DMF was purged with argon for 10 minutes. To this solution was added trimethylsilylacetylene (4.15 g, 42.0 mmol) and bis(triphenylphosphine)-palladium (II) chloride (298.0 mg, 0.425 mmol). The solution was heated to 95° C. for 5 hours, cooled to room temperature, and diluted with H2O. Extraction with EtOAc was followed by washing the combined organic layers with H2O and saturated aqueous NaCl and drying over MgSO4. Concentration of the dry solution under reduced pressure and isolation of the product by column chromatography (3% EtOAc/hexanes) afforded 2.23 g (91%) of the 2,2-dimethyl-6-trimethylsilanylethynyl-thioc-hroman-4-one as an orange oil. 1H NMR (300 MHz, CDCl3) δ: 8.18 (1H, d, J=1.9 Hz), 7.34 (1H, dd, J=1.9, 8.1 Hz), 7.15 (1H, d, J=8.1 Hz), 2.85 (2H, s), 1.45 (6H, s), 0.23 (9H, s).

Quelle