Reaktion #42472

Reaktionsgleichung

methyl 8-bromo-4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

copper cyanide

hydrochloric acid

→

title compound

Ausbeute 66.7%

Methyl 4-butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Ausbeute 66.7%

Lösungsmittel

NMP

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe resulting mixture was cooled to room temperature
2. 2
   ExtraktionThe acidic aqueous layer was extracted with ethyl acetate
3. 3
   Waschenwashed with 1 N hydrochloric acid (15 mL), saturated sodium bicarbonate (15 mL), and brine
4. 4
   Trocknendried (magnesium sulfate)
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigePurification by flash column chromatography (silica, 1:9 ethyl acetate/hexanes)

Vorschrift

To a flask containing methyl 8-bromo-4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (0.33 g) was added NMP (7 mL), followed by copper cyanide (0.18 g). The mixture was then heated to 175° C. and stirred overnight. The resulting mixture was cooled to room temperature and poured into 1 N hydrochloric acid. The acidic aqueous layer was extracted with ethyl acetate, washed with 1 N hydrochloric acid (15 mL), saturated sodium bicarbonate (15 mL), and brine, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:9 ethyl acetate/hexanes) provided 184 mg of the title compound: 1H NMR (300 MHz, CDCl3) δ 7.55, 7.43, 4.41, 3.89, 3.39, 3.31, 1.58, 1.40, 0.97.

Quelle