Sulfuric Acid → (6-Chloro-3-methyl-quinoxalin-5-yl)-acetic acid methyl ester

HRID 1968746Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1968746
[CH3:1][O-:2].[Na+].[Cl:4][C:5]1[C:14]([CH2:15][C:16](Cl)(Cl)Cl)=[C:13]2[C:8]([N:9]=[CH:10][C:11]([CH3:20])=[N:12]2)=[CH:7][CH:6]=1.S(=O)(=O)(O)[OH:22]>CO>[CH3:1][O:2][C:16](=[O:22])[CH2:15][C:14]1[C:5]([Cl:4])=[CH:6][CH:7]=[C:8]2[C:13]=1[N:12]=[C:11]([CH3:20])[CH:10]=[N:9]2

Komponenten

5

Edukt 3

HCID 1118Sulfuric AcidHCID 10942334Sodium MethoxideHCID 668820407-Chloro-2-methyl-8-(2,2,2-trichloroethyl)quinoxaline

Produkt 1

HCID 66882129(6-Chloro-3-methyl-quinoxalin-5-yl)-acetic acid methyl esterAusbeute 46 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel2×

Reaktionsbedingungen

Temperatur
70 °C

Versuchsvorschrift

NaOMe (5.4 M in MeOH, 8.3 ml, 44.71 mmol, 4.5 equiv) was added at room temperature to a solution of 7-chloro-2-methyl-8-(2,2,2-trichloro-ethyl)-quinoxaline (3.08 g, 9.94 mmol) in methanol (24 ml). The reaction mixture was heated to 70° C. for 3 hours. After cooling to 0° C., sulfuric acid (4.7 ml) dissolved in methanol (20 ml) was added, and the reaction mixture was heated to 70° C. for one hour. After cooling and dilution with EtOAc and H2O, the mixture was filtered and extracted with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified via flash chromatography (gradient of hexane/EtOAc 100:0 to 70:30) to afford the title compound (1.14 g, 46%) as a solid. 1H NMR (400 MHz, CDCl3): δ=8.70 (s, 1H), 7.95 (d, J=9.1 Hz, 1H), 7.69 (d, J=9.1 Hz, 1H), 4.48 (s, 2H), 3.70 (s, 3H), 2.74 (s, 3H). MS (ES+): 251.1 (M+H)+.

Aufarbeitung

  1. temperatureAfter cooling to 0° C.
  2. additionwas added
  3. temperaturethe reaction mixture was heated to 70° C. for one hour
  4. temperatureAfter cooling
  5. filtrationdilution with EtOAc and H2O, the mixture was filtered
  6. extractionextracted with EtOAc
  7. washThe combined organic layers were washed with brine
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe residue was purified via flash chromatography (gradient of hexane/EtOAc 100:0 to 70:30)

Quellen und Nachweise

ORD-Eintrag
ord-f40b6e1d3fb840baa996b25380c483d3
Quelldatensatz
uspto-grants-2013_04
Patentnummer
US08426440B2

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