Reaction #302860

Reaction equation

sodium hydroxide

compound 24

6-methoxy-4′-aminoflavone

Sodium cyanoborohydride

paraformaldehyde

→

compound 25

6-methoxy-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 (891 mg, 14.1 mmol) was slowly added to an acetic acid solution (30 ml) that contained compound 24 (630 mg, 2.36 mmol) and paraformaldehyde (707 mg, 23.6 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-methoxy-4′-dimethylaminoflavone (compound 25) in the form of a yellow crystal. Yield: 450 mg (yield constant: 64.6%) 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).

Source