反应详情

Following a procedure similar to that described in Preparation 44(iii), 1.54 g of diethyl 2-acetoxymethyl-imidazole-4,5-dicarboxylate were reacted with 6.5 equivalents of methylmagnesium iodide. Ethyl acetate was then added to the reaction solution, whilst ice-cooling, and the reaction solution was concentrated by evaporation under reduced pressure. The resulting residue was mixed with 50 ml of pyridine and 25 ml of acetic anhydride, and left at room temperature overnight. At the end of this time, 10 ml of methanol were added to the reaction solution, which was then stirred for 30 minutes. The solution was then concentrated by evaporation under reduced pressure. The residue was mixed with water and ethyl acetate, and the ethyl acetate layer was separated, washed twice with a saturated aqueous solution of sodium hydrogencarbonate and then once with an aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through silica gel, using a 1:4 by volume mixture of hexane and ethyl acetate as the eluent, to give 1.46 g of the title compound as a syrup.

1. temperaturecooling
2. concentrationthe reaction solution was concentrated by evaporation under reduced pressure
3. additionThe resulting residue was mixed with 50 ml of pyridine and 25 ml of acetic anhydride
4. additionAt the end of this time, 10 ml of methanol were added to the reaction solution, which
5. concentrationThe solution was then concentrated by evaporation under reduced pressure
6. additionThe residue was mixed with water and ethyl acetate
7. customthe ethyl acetate layer was separated
8. washwashed twice with a saturated aqueous solution of sodium hydrogencarbonate
9. dry with materialonce with an aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate
10. customThe solvent was removed by distillation under reduced pressure
11. customthe resulting residue was purified by column chromatography through silica gel
12. additionby volume mixture of hexane and ethyl acetate as the eluent