Reacción #159773

Ecuación de reacción

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

→

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

Rendimiento 93.9%

Disolventes

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaAfter refluxing for 6 h
2. 2
   Otroquenched by the addition of methanol
3. 3
   OtroVolatiles were evaporated under reduced pressure
4. 4
   Lavadowashed with saturated aq. sodium bicarbonate solution, water, and brine
5. 5
   SecadoThe organic layer was dried over sodium sulfate
6. 6
   Concentraciónconcentrated
7. 7
   Otrothe resulting residue was purified by silica gel column chromatography

Procedimiento

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).

Fuente