Trimethyl orthoformate → N-[5-(1,1-dimethoxy-ethyl)-pyrazin-2-yl]-2,2-dimethyl-propionamide

HRID 719926Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 719926
[C:1]([C:4]1[N:5]=[CH:6][C:7]([NH:10][C:11](=[O:16])[C:12]([CH3:15])([CH3:14])[CH3:13])=[N:8][CH:9]=1)(=[O:3])[CH3:2].O.[C:18]1(C)C=CC(S(O)(=O)=O)=CC=1.[CH:29](OC)(OC)[O:30]C>CO>[CH3:18][O:3][C:1]([C:4]1[N:5]=[CH:6][C:7]([NH:10][C:11](=[O:16])[C:12]([CH3:15])([CH3:14])[CH3:13])=[N:8][CH:9]=1)([O:30][CH3:29])[CH3:2]

Komponenten

5

Edukt 3

HCID 9005Trimethyl orthoformateHCID 521998p-Toluenesulfonic acid monohydrateHCID 21897264N-(5-acetylpyrazin-2-yl)-2,2-dimethylpropanamide

Produkt 1

HCID 21897278N-[5-(1,1-dimethoxy-ethyl)-pyrazin-2-yl]-2,2-dimethyl-propionamideAusbeute 72 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Versuchsvorschrift

A suspension of N-(5-acetyl-pyrazin-2-yl)-2,2-dimethyl-propionamide (prepared as in Example 28, 2.00 g, 9.038 mmol) in trimethyl orthoformate (13.5 mL) and methanol (36 mL) was treated with p-toluenesulfonic acid monohydrate (174.5 mg, 0.904 mmol). The resulting reaction mixture was heated under reflux for 2.5 h and then concentrated in vacuo. The residue was diluted with ethyl acetate (200 mL). The organic layer was washed with a saturated aqueous sodium bicarbonate solution (100 mL) and a saturated aqueous sodium chloride solution (100 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40L, Silica, 1/4 ethyl acetate/hexanes) afforded N-[5-(1,1-dimethoxy-ethyl)-pyrazin-2-yl]-2,2-dimethyl-propionamide as a white solid (1.74 g, 72%): mp 108–109° C.; EI-HRMS m/e calcd for C13H21N3O3 (M+) 267.1583, found 267.1486.

Aufarbeitung

  1. customThe resulting reaction mixture
  2. temperaturewas heated
  3. temperatureunder reflux for 2.5 h
  4. concentrationconcentrated in vacuo
  5. additionThe residue was diluted with ethyl acetate (200 mL)
  6. washThe organic layer was washed with a saturated aqueous sodium bicarbonate solution (100 mL)
  7. dry with materiala saturated aqueous sodium chloride solution (100 mL), dried over magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-a3483595a40c40acb5bd828dbfdbf871
Quelldatensatz
uspto-grants-2006_11
Patentnummer
US07132425B2

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