Chloroform → 4-Bromo-6,7-dimethoxycinnoline

HRID 503516Notes

Reaction equation

P(Br)(Br)([Br:3])=O.[CH3:6][O:7][C:8]1[CH:9]=[C:10]2[C:15](=[CH:16][C:17]=1[O:18][CH3:19])[N:14]=[N:13][CH:12]=[C:11]2O.C(Cl)(Cl)Cl.C([O-])(=O)C.[Na+].C([O-])(O)=O.[Na+]>C(Cl)Cl>[Br:3][C:11]1[C:10]2[C:15](=[CH:16][C:17]([O:18][CH3:19])=[C:8]([O:7][CH3:6])[CH:9]=2)[N:14]=[N:13][CH:12]=1

Participants

Conditions

Temperature: 65 °C

Procedure

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.

Workup

additionThe reaction mixture was poured
customThe organic layer was separated
extractionthe aqueous layer was extracted with dichloromethane (2×200 mL)
washThe combined organic extracts were washed with brine (2×100 mL)
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo
customto provide a light tan oil
filtrationthe resulting solid was filtered

Sources & evidence

ORD record: ord-6c28d135a9e24907b25cc25de5588a02
Source dataset: uspto-grants-2010_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07776857B2

Reaction notes

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