反応 #7917

反応方程式

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

収率 46.5%

溶媒

CH2Cl2

EtOAc

反応条件

後処理

1. 1
   洗浄washed with dilute aqueous Na2S2O3 (4 mL) and brine (4 ml)
2. 2
   乾燥dried over MgSO4
3. 3
   ろ過filtered
4. 4
   その他evaporated under vacuum to a yellow oil (43 mg)
5. 5
   その他This material was purified by preparative layer chromatography on a 0.05×20×20 cm silica gel GF plate

実験手順

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.

出典