Reaktion #2856

Reaktionsgleichung

3-thiophene-2-yl-acrylic acid

triethylamine

tributylamine

sodium azide

ethyl chloroformate

→

title compound

Ausbeute 49.7%

5H-Thieno[3,2-c]pyridin-4-one

Ausbeute 49.7%

Lösungsmittel

acetone

diphenyl ether

H2O

—

hexanes

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationA white precipitate forms which is collected by filtration
2. 2
   TrocknenThe resulting solid is dried over P2O5 under vacuum
3. 3
   workup.WAITAfter 2 h
4. 4
   Temperaturthe solution is cooled to ambient temperatures
5. 5
   Temperaturis cooled to 0° C
6. 6
   FiltrationThe resulting solid is collected by filtration
7. 7
   Waschenthe solid is washed with hexanes

Vorschrift

To a solution of 3-thiophene-2-yl-acrylic acid (7.39 g, 47.9 mmol) in 200 mL of acetone is added triethylamine (4.9 g, 47.9 mmol). The resulting solution is cooled to 0° C. and ethyl chloroformate (5.7 g, 52.8 mmol) is added dropwise. After 2 h, sodium azide (4.67 g, 71.9 mmol) in 25 mL of H2O is then added. The solution is stirred for 1.5 h at 0° C. After this time, the solution is poured into 300 mL of H2O. A white precipitate forms which is collected by filtration. The resulting solid is dried over P2O5 under vacuum. The solid is suspended in 20 mL of diphenyl ether. This solution is added dropwise to a solution of tributylamine (6.9 g, 37.4 mmol) in 200 ml of diphenyl ether at 190° C. After 2 h, the solution is cooled to ambient temperatures. The solution is diluted with 1000 mL of hexanes and is cooled to 0° C. The resulting solid is collected by filtration and the solid is washed with hexanes. The title compound (3.6 g, 23.8 mmol) is obtained as a white solid.

Quelle