Reaktion #155546

Reaktionsgleichung

HCl

sodium methoxide

pyrazine-2-carbonitrile

acetic acid

2,2-Diethoxyethanamine

→

desired compound

2-(1H-Imidazol-2-yl)pyrazine

Lösungsmittel

MeOH

methanol

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe subsequent solution was stirred at 50° C. for 1 hour
2. 2
   workup.STIRRINGthe reaction was stirred
3. 3
   Temperaturat reflux overnight
4. 4
   TemperaturThe reaction mixture was cooled to room temperature
5. 5
   Sonstigepartitioned between 1:1 Et2O and water (60 mL)
6. 6
   Sonstigethe layers were separated
7. 7
   Extraktionextracted with 10% MeOH in DCM
8. 8
   TrocknenThe combined organic extracts were dried (MgSO4)
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated

Vorschrift

2,2-Diethoxyethanamine (3 g, 2.25 mmol) was dissolved in dry methanol (20 mL). To this was added sodium methoxide (1.22 g, 22.5 mmol, as a 25% solution in methanol). After stirring for 25 minutes at room temperature, pyrazine-2-carbonitrile (2.37 g, 22.5 mmol) and acetic acid (1.35 g, 22.5 mmol) were added and the subsequent solution was stirred at 50° C. for 1 hour. MeOH (40 mL) and 6N HCl (12 mL) were added and the reaction was stirred at reflux overnight. The reaction mixture was cooled to room temperature and partitioned between 1:1 Et2O and water (60 mL) and the layers were separated. The aqueous layer was basified to pH 9/10 and extracted with 10% MeOH in DCM. The combined organic extracts were dried (MgSO4), filtered and concentrated to give the desired compound (1.49 g yellow solid). 1H NMR (400 MHz, MeOH-d4) δ ppm: 7.67 (s, 1 H), 7.09 (d, J=1.8 Hz, 1 H), 6.99 (d, J=2.5 Hz, 1 H), 5.72 (s, 2 H)

Quelle