Reaction #302850

Reaction equation

sodium hydroxide

compound 5

6-bromo-4′-aminoflavone

Sodium cyanoborohydride

paraformaldehyde

→

compound 7

6-bromo-4′-dimethylaminoflavone

Solvents

acetic acid

Conditions

Workup

1. 1
   workup.STIRRINGThe obtained mixture was stirred at room temperature for 3 hours
2. 2
   workup.ADDITIONwas added to the reaction solution
3. 3
   Extractionthe obtained mixture was then extracted with 50 ml (25 ml×2) of chloroform
4. 4
   DryingThe extract was dried over anhydrous sodium sulfate
5. 5
   workup.DISTILLATIONthe solvent was then distilled away under reduced pressure

Procedure

Sodium cyanoborohydride (74.5 mg, 1.19 mmol) was slowly added dropwise to an acetic acid solution (10 ml) that contained compound 5 (75 mg, 0.237 mmol) and paraformaldehyde (71.1 mg, 2.37 mmol), while stirring. The obtained mixture was stirred at room temperature for 3 hours. After completion of the reaction, 50 ml of a 1 N sodium hydroxide aqueous solution was added to the reaction solution, and the obtained mixture was then extracted with 50 ml (25 ml×2) of chloroform. The extract was dried over anhydrous sodium sulfate, and the solvent was then distilled away under reduced pressure, so as to obtain a product of interest, 6-bromo-4′-dimethylaminoflavone (compound 7) in the form of a yellow crystal. Yield: 70 mg (yield constant: 85.7%) 1H NMR (300 MHz, CDCl3) δ8.34 (s, 1H), 7.72-7.82 (m, 3H), 7.43 (d, J=9.0 Hz, 1H), 6.70-6.77 (m, 3H), 3.08 (s, 6H). MS m/z 345 (M+).

Source