Reaktion #76844

Reaktionsgleichung

( D )

2-Hydroxy-2′nitro-3,4′-diphenyl-5-tert-octylazobenzene

sodium hydroxide

2-hydroxy-2′nitro-3,4′-diphenyl-5-tert-octylazobenzene

→

title compound

5-Phenyl-2-(2-hydroxy-3-phenyl-5-tert-octylphenyl)-2H-benzotriazole

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is heated
2. 2
   Temperaturto reflux
3. 3
   TemperaturThe reaction mixture is heated
4. 4
   Temperaturat reflux for 1.5 hours
5. 5
   SonstigeTo the cooled reaction mixture
6. 6
   Sonstigethe ethanol is removed under vacuum
7. 7
   ExtraktionThe resultant mixture is extracted twice with methylene chloride
8. 8
   Extraktionthe combined organic phases are extracted with water
9. 9
   TrocknenThe organic phase is dried ovdr anhydrous magnesium sulfate
10. 10
    Sonstigethe solvent is then removed under vacuum
11. 11
    SonstigeThe residue is recrystallized sequentially from a mixture of water and methanol, and petroleum ether

Vorschrift

To a solution of sodium hydroxide (6 g, 0.15 mol) in 8 mL of water is added 2-hydroxy-2′nitro-3,4′-diphenyl-5-tert-octylazobenzene (6.56 g), prepared in (D) above. The reaction mixture is heated to reflux and then formadine sulfinic acid (10.8 g, 0.1 mol) is added portionwise over 20 minutes. The reaction mixture is heated at reflux for 1.5 hours. To the cooled reaction mixture is added 200 mL of water and the ethanol is removed under vacuum. The reaction mixture is adjusted to pH 4 with hydrochloric acid. The resultant mixture is extracted twice with methylene chloride and the combined organic phases are extracted with water. The organic phase is dried ovdr anhydrous magnesium sulfate, and the solvent is then removed under vacuum. The residue is recrystallized sequentially from a mixture of water and methanol, and petroleum ether to give the title compound as a white solid melting at 123-125° C.

Quelle