反应 #3741

反应方程式

Oxalyl chloride

2-ethoxybenzoic acid

dimethylformamide

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

→

title compound

收率 77.0%

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

收率 77.0%

溶剂

dichloromethane

pyridine

反应条件

后处理

1. 1
   其他evaporated under vacuum
2. 2
   其他The residue was azeotroped with dichloromethane (2×20 ml)
3. 3
   workup.STIRRINGwas stirred at ambient temperature for 3 days
4. 4
   其他evaporated under vacuum
5. 5
   workup.DISSOLUTIONThe residue was dissolved in dichloromethane (50 ml)
6. 6
   洗涤the solution washed with 1N hydrochloric acid (30 ml)
7. 7
   干燥dried (Na2SO4)
8. 8
   其他evaporated under vacuum
9. 9
   洗涤a methanol in dichloromethane elution gradient (2-6% methanol)
10. 10
    其他followed by crystallisation from ethanol

实验过程

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%.

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