反应详情

A solution of diethyl [2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzyl-malonate [Example 8(iii)] (5.54 g, 0.0108 mol) in ethanol (75 mL) was treated all at once with a solution of potassium hydroxide (3.65 g, 0.065 mol) in water (50 mL). The resulting mixture was stirred at room temperature for 24 hours, then refluxed for 3 hours. The ethanol was evaporated, water was added to the aqueous product, and the basic solution was extracted with diethyl ether. The aqueous layer was acidified to pH 4 with hydrochloric acid and the product was extracted into ethyl acetate. The dried, concentrated product was crystallized twice from ethyl acetate to give 0.6 g of 2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzyl-malonic acid; mp 165°-166° C.(d). The filtrates from the crystallizations (4.9 g) consisted of additional malonic acid, the propanoic acid derivative and the mono ethyl ester malonate derivative. These are converted to [ 2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzylpropanoic acid by the method described previously.

1. temperaturerefluxed for 3 hours
2. customThe ethanol was evaporated
3. additionwater was added to the aqueous product
4. extractionthe basic solution was extracted with diethyl ether
5. extractionthe product was extracted into ethyl acetate
6. customThe dried, concentrated product was crystallized twice from ethyl acetate