Reaktion #3741

Reaktionsgleichung

Oxalyl chloride

2-ethoxybenzoic acid

dimethylformamide

5-amino-1-n-propylimidazole-4-carboxamide

→

title compound

Ausbeute 77.0%

5-(2-Ethoxybenzamido)-1-n-propylimidazole-4-carboxamide

Ausbeute 77.0%

Lösungsmittel

dichloromethane

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeevaporated under vacuum
2. 2
   SonstigeThe residue was azeotroped with dichloromethane (2×20 ml)
3. 3
   workup.STIRRINGwas stirred at ambient temperature for 3 days
4. 4
   Sonstigeevaporated under vacuum
5. 5
   workup.DISSOLUTIONThe residue was dissolved in dichloromethane (50 ml)
6. 6
   Waschenthe solution washed with 1N hydrochloric acid (30 ml)
7. 7
   Trocknendried (Na2SO4)
8. 8
   Sonstigeevaporated under vacuum
9. 9
   Waschena methanol in dichloromethane elution gradient (2-6% methanol)
10. 10
    Sonstigefollowed by crystallisation from ethanol

Vorschrift

Oxalyl chloride (1.74 g, 0.137 mol) was added dropwise to a stirred solution of 2-ethoxybenzoic acid (1.1 g, 0.00663 mol) and dimethylformamide (0.1 ml) in dichloromethane (20 ml) and the resulting mixture stirred at ambient temperature for 4 hours, then evaporated under vacuum. The residue was azeotroped with dichloromethane (2×20 ml), then added dropwise to a stirred solution of 5-amino-1-n-propylimidazole-4-carboxamide (0.9 g, 0.00536 mol) in pyridine (20 ml) The resulting solution was stirred at ambient temperature for 3 days, then evaporated under vacuum. The residue was dissolved in dichloromethane (50 ml), and the solution washed with 1N hydrochloric acid (30 ml), dried (Na2SO4) and evaporated under vacuum. Chromatography of the crude product on silica gel (15 g) using a methanol in dichloromethane elution gradient (2-6% methanol), followed by crystallisation from ethanol, gave the title compound as a colourless solid (1.3 g, 77%), m.p. 182°-184° C. Found: C,60.85; H,6.40; N,18.06. C16H20N4O3 requires C,60.74; H,6.37; N,17.71%.

Quelle