Reaktion #42496

Reaktionsgleichung

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

9-BBN

ethanolamine

→

title compound

Ausbeute 80.1%

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

Ausbeute 80.1%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe resulting solution was concentrated under reduced pressure
2. 2
   WaschenThe residue was washed with hexanes
3. 3
   Filtrationfiltered
4. 4
   Einengenthe filtrate was concentrated under reduced pressure
5. 5
   SonstigePurification by flash column chromatography (silica, 25% ethyl acetate/hexanes)

Vorschrift

A solution of methyl 4-butyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (800 mg) and 9-BBN (1.6 g) in tetrahydrofuran (13 mL) was refluxed for 1.5 h. The mixture was cooled to room temperature, ethanolamine (0.4 mL) was added, and the resulting solution was concentrated under reduced pressure. The residue was washed with hexanes, filtered, and the filtrate was concentrated under reduced pressure. Purification by flash column chromatography (silica, 25% ethyl acetate/hexanes) afforded 607 mg of the title compound: 1H NMR (300 MHz, DMSO-d6) δ 7.21, 7.16, 6.75, 4.24-4.21, 3.78, 3.34-3.24, 1.55-1.47, 1.38-1.30, 0.95-0.90.

Quelle