Reaktion #590698

Reaktionsgleichung

Phosphorus oxybromide

6,7-dimethoxycinnolin-4-ol

chloroform

NaHCO3

sodium acetate

→

4-bromo-6,7-dimethoxycinnoline

Lösungsmittel

—

hexanes

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThe reaction mixture was poured
2. 2
   SonstigeThe organic layer was separated
3. 3
   Extraktionthe aqueous layer was extracted with dichloromethane (2×200 mL)
4. 4
   WaschenThe combined organic extracts were washed with brine (2×100 mL)
5. 5
   Trocknendried over Na2SO4
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated in vacuo
8. 8
   Sonstigeto provide a light tan oil
9. 9
   Filtrationthe resulting solid was filtered

Vorschrift

Phosphorus oxybromide (125 g, 0.436 mol) was added to a suspension of 6,7-dimethoxycinnolin-4-ol (65 g, 0.32 mol) in chloroform (550 mL, 6.9 mol). The reaction mixture was stirred at 65° C. for 18 hours. Formation of a fine yellow solid was observed. The reaction mixture was poured onto crushed ice (200 g), and the pH was adjusted to 6-7 with sodium acetate (285 g) and sat. NaHCO3. The organic layer was separated, and the aqueous layer was extracted with dichloromethane (2×200 mL). The combined organic extracts were washed with brine (2×100 mL), dried over Na2SO4, filtered, and concentrated in vacuo to provide a light tan oil. DCM (40 mL) and hexanes (250 mL) were added, and the resulting solid was filtered to provide 4-bromo-6,7-dimethoxycinnoline as an off-white solid.

Quelle