Reaktion #436167

Reaktionsgleichung

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

potassium hydroxide

→

title compound

Ausbeute 88.2%

4-Butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acid

Ausbeute 88.2%

Lösungsmittel

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthen concentrated under reduced pressure
2. 2
   workup.ADDITIONThe residue was diluted with water
3. 3
   Waschenwashed with ethyl acetate
4. 4
   Extraktionextracted with chloroform (4×100 mL)
5. 5
   TrocknenThe combined organic extracts were dried (sodium sulfate)
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated under reduced pressure

Vorschrift

To a stirred solution of Methyl 4-butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (184 mg) in methanol (3 mL) was added potassium hydroxide (7 mL of a 1.0 M solution in water). The mixture was stirred at room temperature overnight then concentrated under reduced pressure. The residue was diluted with water and washed with ethyl acetate. The aqueous layer was acidified to pH 4 with 1 N hydrochloric acid and extracted with chloroform (4×100 mL). The combined organic extracts were dried (sodium sulfate), filtered, and concentrated under reduced pressure to give 154 mg of the title compound: 1H NMR (300 MHz, CDCl3) (57.62, 7.46, 4.44, 3.41, 3.33, 1.60, 1.41, 0.98.

Quelle