反応 #3741

反応方程式

Oxalyl chloride

2-ethoxybenzoic acid

dimethylformamide

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

→

title compound

収率 77.0%

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

収率 77.0%

溶媒

dichloromethane

pyridine

反応条件

後処理

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

実験手順

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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