Dimethylformamide → t-Butyl 5-nitroindole-2-carboxylate

HRID 1356583

Reaktionsgleichung

Reaktionsgleichung von HRID 1356583
[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][C:8]([C:13]([OH:15])=[O:14])=[CH:7]2)([O-:3])=[O:2].C(Cl)(=O)C(Cl)=O.CN(C=O)C.[CH3:27][C:28]([CH3:31])([O-])[CH3:29].[K+]>C1COCC1>[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][C:8]([C:13]([O:15][C:28]([CH3:31])([CH3:29])[CH3:27])=[O:14])=[CH:7]2)([O-:3])=[O:2]

Komponenten

6

Edukt 4

HCID 6228DimethylformamideHCID 65578Oxalyl chlorideHCID 3512915-Nitroindole-2-carboxylic acidHCID 23665647Potassium tert-butoxide

Produkt 1

HCID 10801431t-Butyl 5-nitroindole-2-carboxylateAusbeute 85 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
30 °C

Versuchsvorschrift

To a stirred solution of 9 (12.8 g, 61.2 mmol) in dry THF (200 mL) under argon was added oxalyl chloride (12.0 mL, 137.5 mmol) followed by DMF (0.1 mL), which caused a vigorous evolution of gas. After 40 min, the reaction mixture was evaporated to dryness. The resulting solid was re-dissolved in THF (150 mL), cooled to ˜30° C., and stirred under argon. A solution of potassium t-butoxide (1.0 M in THF, 140 mL, 140 mmol) was then added dropwise over 45 min, and stirring was continued for an additional 45 min. The reaction was quenched with 600 mL of water, neutralized with few drops of a 10% aqueous solution of H3PO4 and extracted with ethyl acetate (3×400 mL). The organic extracts were washed with saturated aqueous NaHCO3, water, and then dried over magnesium sulfate, filtered, concentrated and crystallized with ethanol/hexane to afford compound 10 (9.62 g, 85% yield). Rf=0.35 (1:5 Ethyl acetate/Hexane); 1H NMR (CDCl3), 11.63 (s, 1H), 8.66 (dd, 1H, J=0.5, 1.3Hz), 8.20 (dd, 1H, J=0.5, 9.0 Hz), 7.48 (dd, 1H, J=0.5, 9.1 Hz), 7.28 (dd, 1H, J=0.9, 11.1 Hz), 1.63 (s, 9H); 13C NMR 160.39, 142.12, 138.11, 132.10, 126.78, 120.22, 119.83, 111.98, 109.82, 82.91, 28.26; MS m/z 285.43 (M+Na)+.

Aufarbeitung

  1. customthe reaction mixture was evaporated to dryness
  2. dissolutionThe resulting solid was re-dissolved in THF (150 mL)
  3. stirringstirring
  4. waitwas continued for an additional 45 min
  5. customThe reaction was quenched with 600 mL of water
  6. extractionextracted with ethyl acetate (3×400 mL)
  7. washThe organic extracts were washed with saturated aqueous NaHCO3, water
  8. dry with materialdried over magnesium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customcrystallized with ethanol/hexane

Quellen und Nachweise

ORD-Eintrag
ord-8bc097662a114c07b534302a9e2f3b43
Quelldatensatz
uspto-grants-2003_07
Patentnummer
US06586618B1

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