Reaktion #159773

Reaktionsgleichung

6-bromospiro[4H-1,4-benzoxazine-2,1′-cyclopropane]-3-one

→

6-bromospiro[3,4-dihydro-1,4-benzoxazine-2,1′-cyclopropane]

Ausbeute 93.9%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter refluxing for 6 h
2. 2
   Sonstigequenched by the addition of methanol
3. 3
   SonstigeVolatiles were evaporated under reduced pressure
4. 4
   Waschenwashed with saturated aq. sodium bicarbonate solution, water, and brine
5. 5
   TrocknenThe organic layer was dried over sodium sulfate
6. 6
   Einengenconcentrated
7. 7
   Sonstigethe resulting residue was purified by silica gel column chromatography

Vorschrift

To a stirred solution of 6-bromospiro[4H-1,4-benzoxazine-2,1′-cyclopropane]-3-one (2.6 g, 10.2 mmol) in THF (20 mL) was added 1 M solution of borane-tetrahydrofuran complex in THF (51.0 mL, 51.2 mmol). After refluxing for 6 h, the reaction mixture was cooled to room temperature and quenched by the addition of methanol. Volatiles were evaporated under reduced pressure, and the resulting residue was taken up in ethyl acetate and washed with saturated aq. sodium bicarbonate solution, water, and brine. The organic layer was dried over sodium sulfate, concentrated, and the resulting residue was purified by silica gel column chromatography to furnish 6-bromospiro[3,4-dihydro-1,4-benzoxazine-2,1′-cyclopropane] (2.3 g).

Quelle