Hydrochloric Acid → 8-chloro-3-ethyl-3,4-dihydroquinoxalin-2(1H)-one

HRID 75370

Reaktionsgleichung

Reaktionsgleichung von HRID 75370
[Cl:1][C:2]1[C:3]([N+:15]([O-])=O)=[C:4]([NH:8][CH:9]([CH2:13][CH3:14])[C:10](O)=[O:11])[CH:5]=[CH:6][CH:7]=1.Cl.O.O.Cl[Sn]Cl.[OH-].[K+]>CCO>[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]2[C:3]=1[NH:15][C:10](=[O:11])[CH:9]([CH2:13][CH3:14])[NH:8]2

Komponenten

6

Edukt 4

HCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 61436Stannous chloride dihydrateHCID 866985082-((3-Chloro-2-nitrophenyl)amino)butanoic acid

Produkt 1

HCID 846214318-chloro-3-ethyl-3,4-dihydroquinoxalin-2(1H)-oneAusbeute 90 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 702EthanolLösungsmittel

Versuchsvorschrift

To a solution of 2-((3-chloro-2-nitrophenyl)amino)butanoic acid (1.5 Kg, 5.8 mol), 4 N aq. HCl (4.35 L, 17.4 mol) and EtOH (5.3 L) was added SnCl2.2H2O (3.93 Kg, 17.4 mol). The reaction mixture was heated to reflux for 5 h. At this time LC-MS analysis showed that the reaction was complete. After cooling to rt the reaction mixture was evaporated under reduced pressure. The resulting residue was cooled to 0° C. using an ice-water bath and an aqueous solution of 10 N KOH (12 L, 180 mol) was carefully added with vigorous stirring. After filtration to remove insoluble solids, the filtrate was extracted with DCM (2×10 L) washed with water, brine, dried over anhydrous Na2SO4, and evaporated under reduced pressure to give 8-chloro-3-ethyl-3,4-dihydroquinoxalin-2(1H)-one (1.1 Kg) as a yellow solid, which was used without further purification. 1H NMR (DMSO-d6) δ ppm 9.70 (s, 1H), 6.65-6.83 (m, 3H), 6.31-6.44 (m, 1H), 3.66-3.72 (m, 1H), 1.53-1.71 (m, 2H), 0.92 (t, J=7.4 Hz, 3H). Mass Spectrum (ESI) m/z=211.2 (M+1).

Aufarbeitung

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 5 h
  3. customwas evaporated under reduced pressure
  4. temperatureThe resulting residue was cooled to 0° C.
  5. filtrationAfter filtration
  6. customto remove insoluble solids
  7. extractionthe filtrate was extracted with DCM (2×10 L)
  8. washwashed with water, brine
  9. dry with materialdried over anhydrous Na2SO4
  10. customevaporated under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-da06148f94a5423da4a46d373abe8a77
Quelldatensatz
uspto-grants-2014_09
Patentnummer
US08835432B2

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