Reacción #3741

Ecuación de reacción

Oxalyl chloride

2-ethoxybenzoic acid

dimethylformamide

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

→

title compound

Rendimiento 77.0%

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

Rendimiento 77.0%

Disolventes

dichloromethane

pyridine

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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%.

Fuente