Reacción #7917

Ecuación de reacción

7-methoxy-9a-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

NaHCO3

bromine

→

4-bromo-7-methoxy-9a-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Rendimiento 46.5%

Disolventes

CH2Cl2

EtOAc

Condiciones de reacción

Tratamiento posterior

1. 1
   Lavadowashed with dilute aqueous Na2S2O3 (4 mL) and brine (4 ml)
2. 2
   Secadodried over MgSO4
3. 3
   Filtraciónfiltered
4. 4
   Otroevaporated under vacuum to a yellow oil (43 mg)
5. 5
   OtroThis material was purified by preparative layer chromatography on a 0.05×20×20 cm silica gel GF plate

Procedimiento

A mixture of 7-methoxy-9a-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (32 mg, 0.14 mmol) and NaHCO3 (60 mg, 0.7 mmol) in CH2Cl2 (0.5 ml) was treated with bromine (0.008 mL, 0.154 mmol), and the resulting mixture was stirred at room temperature for 22 hours. The mixture was diluted with EtOAc (8 ml), washed with dilute aqueous Na2S2O3 (4 mL) and brine (4 ml), dried over MgSO4, filtered, and evaporated under vacuum to a yellow oil (43 mg). This material was purified by preparative layer chromatography on a 0.05×20×20 cm silica gel GF plate, developing twice with CH2Cl2, to afford 4-bromo-7-methoxy-9a-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (20 mg) as a gum. The product was contaminated with a trace of 4,6-dibromo-7-methoxy-9a-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one.

Fuente