Hydrogen Bromide → 2,3-bis(4-Hydroxyphenyl)quinoxaline-6-carboxylic Acid

HRID 396865

Reaktionsgleichung

Reaktionsgleichung von HRID 396865
C[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[C:18]([C:19]3[CH:24]=[CH:23][C:22]([O:25]C)=[CH:21][CH:20]=3)=[N:17][C:16]3[C:11](=[CH:12][CH:13]=[C:14]([C:27]([OH:29])=[O:28])[CH:15]=3)[N:10]=2)=[CH:5][CH:4]=1.Br.[K+].[Br-]>C(O)(=O)C>[OH:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]2[C:18]([C:19]3[CH:24]=[CH:23][C:22]([OH:25])=[CH:21][CH:20]=3)=[N:17][C:16]3[C:11](=[CH:12][CH:13]=[C:14]([C:27]([OH:29])=[O:28])[CH:15]=3)[N:10]=2)=[CH:7][CH:8]=1

Komponenten

5

Edukt 3

HCID 260Hydrogen BromideHCID 253877Potassium BromideHCID 9803122,3-Bis(4-methoxyphenyl)quinoxaline-6-carboxylic acid

Produkt 1

HCID 9785422,3-bis(4-Hydroxyphenyl)quinoxaline-6-carboxylic Acid

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 176Acetic AcidLösungsmittel

Versuchsvorschrift

Into a 1000 mL three-necked, round-bottomed flask equipped with a magnetic stirrer, a nitrogen inlet, and a condenser, 2,3-bis(4-methoxyphenyl)-quinoxaline-6-carboxylic acid (34.7 g, 89.8 mmol) was dissolved in acetic acid (260 mL). Hydrobromic acid (48%, 500 mL) was then added to yellow clear mixture at room temperature. The reaction mixture was heated under reflux with vigorous stirring until the solution become homogeneous. It took about 6 h. After having been allowed to cool down to room temperature, the red-brown mixture was poured into distilled water. The resulting light brown precipitate was collected by suction filtration and dried under the reduced pressure to give 31.9 g (99% crude yield) of yellow solid, m.p. 315-317° C. (dec.). Anal. Calcd. for C21H14N2O4: C, 70.39%; H, 3.94%; N, 7.82%. Found: C, 66.70%; H, 3.98%; N, 7.20%. FT-IR (KBr, cm−1): 1698 (carbonyl), 3396 (hydroxy). Mass spectrum (m/e): 358 (M+, 100% relative abundance). 1H-NMR (DMSO-d6, δ in ppm): 6.76-6.79 (d, 4H, Ar), 7.35-7.39 (d, 4H, Ar), 8.09-8.12 (d, 1H, Ar), 8.20-8.24 (d, 1H, Ar), 9.87-9.89 (d, 1H, OH), 13.50 (s, 1H, COOH). 13C-NMR (DMSO-d6, δ in ppm): 114.93, 128.78, 129.21, 129.27, 130.39, 131.11, 131.23, 139.29, 142.06, 153.78, 154.38, 158.30, 158.44, 166.62.

Aufarbeitung

  1. customInto a 1000 mL three-necked, round-bottomed flask equipped with a magnetic stirrer, a nitrogen inlet, and a condenser
  2. temperatureThe reaction mixture was heated
  3. temperatureunder reflux
  4. additionthe red-brown mixture was poured
  5. distillationinto distilled water
  6. filtrationThe resulting light brown precipitate was collected by suction filtration
  7. customdried under the reduced pressure
  8. customto give 31.9 g (99% crude yield) of yellow solid, m.p. 315-317° C. (dec.)

Quellen und Nachweise

ORD-Eintrag
ord-c1e632bc81a1468a830de50780c733e8
Quelldatensatz
uspto-grants-2003_08
Patentnummer
US06608171B1

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