Hydrochloric Acid → 2-Methylimidazo[1,2-a]pyridine-8-carbaldehyde

HRID 544470Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 544470
[NH2:1][C:2]1[N:9]=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].Br[CH2:11][C:12](=O)[CH3:13].Cl>C(COC)OC.C(O)C.O>[CH3:13][C:12]1[N:1]=[C:2]2[C:3]([CH:4]=[O:5])=[CH:6][CH:7]=[CH:8][N:9]2[CH:11]=1

Komponenten

7

Edukt 3

HCID 313Hydrochloric AcidHCID 11715BromoacetoneHCID 7376333-Pyridinecarboxaldehyde, 2-amino-

Produkt 1

HCID 139002412-Methylimidazo[1,2-a]pyridine-8-carbaldehyde

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 702EthanolLösungsmittel2×HCID 962WaterLösungsmittelHCID 80711,2-DimethoxyethaneLösungsmittel

Versuchsvorschrift

A mixture of 2-aminonicotinaldehyde (92.8 g, 0.76 mol) and bromoacetone (114.5 g, 0.84 mol) in dimethoxyethane (980 ml) is stirred for 2 hr. at room temperature and then heated at 65° with stirring for 14 hr. The solid which separates is isolated by filtration, dissolved in 800 ml absolute ethanol and heated under reflux for 6 hrs. The ethanol solvent isremoved under reduced pressure and the residue treated with 138 ml 6 N hydrochloric acid in 750 ml water for 0.5 hr. The acidic aqueous layer is washed with ether (2×300 ml) and basified with cooling (78 ml 50% sodium hydroxide and 25 g sodium bicarbonate). The aqueous layer is extracted with dichloromethane. The extracts are combined and dried over anhydrous sodium sulfate. Following filtration, the solvent is removed under reduced pressure to afford 2-methyl-8-formylimidazo[1,2-a]pyridine, mp 136°-139.5° C.

Aufarbeitung

  1. stirringwith stirring for 14 hr
  2. customThe solid which separates is isolated by filtration
  3. temperatureheated
  4. temperatureunder reflux for 6 hrs
  5. washThe acidic aqueous layer is washed with ether (2×300 ml)
  6. temperaturewith cooling (78 ml 50% sodium hydroxide and 25 g sodium bicarbonate)
  7. extractionThe aqueous layer is extracted with dichloromethane
  8. dry with materialdried over anhydrous sodium sulfate
  9. filtrationfiltration
  10. customthe solvent is removed under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-7cffbc95f15649e6b9e23676620e6eba
Quelldatensatz
uspto-grants-1984_05
Patentnummer
US04450164

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