Reaktion #162364

Reaktionsgleichung

hydrochloric acid

ethyl 5-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-2H-1,2-oxazine-2-carboxylate

product

ethyl 5-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-2H-1,2-oxazine-2-carboxylate

potassium hydroxide

sodium hydroxide

→

title compound

5-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-2H-1,2-oxazine

Lösungsmittel

ethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 20 h
2. 2
   Temperaturheated at 70° C. for about 20 minutes
3. 3
   Temperaturcooled to room temperature
4. 4
   ExtraktionThe reaction mixture was extracted with ethyl acetate (20 mL)
5. 5
   Einengenwere concentrated under reduced pressure

Vorschrift

A solution of ethyl 5-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]tetrahydro-2H-1,2-oxazine-2-carboxylate (i.e. the product of Step J) (0.30 g, 0.71 mmol) and potassium hydroxide (0.20 g, 3.50 mmol) in ethanol (10 mL) and water (1 mL) was heated at reflux for 20 h, and then cooled to room temperature. The reaction mixture was acidified by the addition of concentrated hydrochloric acid, heated at 70° C. for about 20 minutes, cooled to room temperature, and then basified by the addition of sodium hydroxide (1%). The reaction mixture was extracted with ethyl acetate (20 mL) and combined organic extracts were concentrated under reduced pressure to provide the title compound as a yellow oil (0.235 g) which was used without purification.

Quelle