反应详情

Dimethyl- 4-amino-isophthalate (5 g) in 50 ml of dioxane and 10 ml of anhydrous pyridine is treated with 7.5 g of 2-ethoxy-3-methoxybenzoyl chloride at room temperature, overnight. After dilution with water, the precipitate is collected, dissolved in ethyl acetate, and washed with 5% NaHCO3 and then with water. After evaporation to dryness under vacuum, the material is crystallized from isopropyl ether, yielding dimethyl- 4-(2'-ethoxy-3'-methoxy-benzoylamino)-isophthalate (9 g; m.p. 113°-115° C.), which is dissolved in 80 ml of dioxane and treated with 70 ml of 1N NaOH at room temperature for 4 hours. After acidification with diluted HCl, the precipitate is collected under vacuum and washed with water until neutral. The yield is 7.4 g of 4-(2'-ethoxy-3'-methoxy-benzoylamino)-isophthalic acid (m.p.=244°-246° C.), which are treated with 10 ml of acetic anhydride at the reflux temperature for 10'.

1. customAfter dilution with water, the precipitate is collected
2. dissolutiondissolved in ethyl acetate
3. washwashed with 5% NaHCO3
4. customAfter evaporation to dryness under vacuum
5. customthe material is crystallized from isopropyl ether