Réaction #3741

Équation de réaction

Oxalyl chloride

2-ethoxybenzoic acid

dimethylformamide

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

→

title compound

Rendement 77.0%

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

Rendement 77.0%

Solvants

dichloromethane

pyridine

Conditions de réaction

Traitement

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

Mode opératoire

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%.

Source