反応 #302849

反応方程式

sodium borohydride

compound 5

6-bromo-4′-aminoflavone

sodium methylate methanol

paraformaldehyde

→

compound 6

6-bromo-4′-methylaminoflavone

溶媒

methanol

反応条件

後処理

1. 1
   温度The obtained mixture was heated
2. 2
   温度to reflux for 1 hour
3. 3
   workup.ADDITIONwas added to the reaction solution by slow degrees
4. 4
   温度the obtained mixture was further heated
5. 5
   温度to reflux for 2 hours
6. 6
   workup.DISTILLATIONThereafter, the reaction solvent was distilled away under reduced pressure

実験手順

A sodium methylate-methanol solution (0.27 ml) was slowly added dropwise to a methanol solution (15 ml) that contained compound 5 (300 mg, 0.949 mmol) and paraformaldehyde (154 mg, 5.13 mmol), while stirring. The obtained mixture was heated to reflux for 1 hour. Thereafter, sodium borohydride (180 mg, 4.75 mmol) that was in the form of a solid was added to the reaction solution by slow degrees, and the obtained mixture was further heated to reflux for 2 hours. Thereafter, the reaction solvent was distilled away under reduced pressure, and the residue was then subjected to silica gel column chromatography using ethyl acetate/hexane (3/5) as an elution solvent, so as to obtain a product of interest, 6-bromo-4′-methylaminoflavone (compound 6). Yield: 121 mg (yield constant: 38.6%) 1H NMR (300 MHz, CDCl3) δ8.31 (s, 1H), 7.69-7.75 (m, 3H), 7.39 (d, J=8.7 Hz, 1H), 6.62-6.66 (m, 3H), 4.18 (s, 1H). 2.91 (s, 3H).

出典