Reaktion #5999

Reaktionsgleichung

benzyloxycarbonyl chloride

hydrochloric acid

sodium borate

dopamine hydrochloride

sodium hydroxide

sodium hydroxide

→

desired compound

Ausbeute 96.5%

N-carbobenzoxydopamine

Ausbeute 96.5%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo the solution thus obtained
2. 2
   Temperaturto maintain the pH value of the reaction mixture to 9
3. 3
   Sonstigestirring for 2 hours
4. 4
   Extraktionextracted with diethyl ether
5. 5
   TrocknenNext, it was dried over anhydrous magnesium sulfate
6. 6
   workup.DISTILLATIONthe solvent was distilled off
7. 7
   WaschenAfter washing the residue with petroleum ether
8. 8
   Sonstigethe crude crystals thus obtained
9. 9
   Sonstigewere recrystallized from ethanol/n-hexane (1 : 1 by volume)

Vorschrift

38.2 g (100 mmol) of sodium borate and 18.9 g (100 mmol) of dopamine hydrochloride were dissolved in 250 ml of water. To the solution thus obtained, was added a 2 N sodium hydroxide solution under a nitrogen gas stream to adjust the pH value to 9. Then 17.1 g (100 mmol) of benzyloxycarbonyl chloride was added dropwise thereto while stirring at 15° C. for 4 hours. Simultaneously, a 2 N sodium hydroxide solution was added to maintain the pH value of the reaction mixture to 9. After continuing the stirring for 2 hours, the mixture was adjusted to pH 1 to 2 with hydrochloric acid and then extracted with diethyl ether. Next, it was dried over anhydrous magnesium sulfate and the solvent was distilled off. After washing the residue with petroleum ether, the crude crystals thus obtained were recrystallized from ethanol/n-hexane (1 : 1 by volume). Thus 27.6 g (yield: 96.5% of the desired compound (m.p.: 134°- 135 ° C.) was obtained in the form of white crystals.

Quelle