反应详情

The compound prepared in Example 20 was dissolved in N,N-dimethylformamide (60 mL). To this solution, 4-isobutylbenzoic acid (6.7 g), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (7.28 g), and 1-hydroxybenzotriazole monohydrate (5.1 g) were added at room temperature. The reaction solution was stirred at room temperature for 30 minutes, and stirred at 140° C. for 2 hours. The reaction mixture was added with water (50 mL), and extracted with an ethyl acetate-hexane (10:1) mixed solution. The extract was successively washed with 0.5 mol/L hydrochloric acid, saturated sodium hydrogen carbonate solution, and water. The resultant was dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=1:1), to thereby obtain the title compound (4.14 g) having the following physical properties.

1. stirringstirred at 140° C. for 2 hours
2. extractionextracted with an ethyl acetate-hexane (10:1)
3. additionmixed solution
4. washThe extract was successively washed with 0.5 mol/L hydrochloric acid, saturated sodium hydrogen carbonate solution, and water
5. dry with materialThe resultant was dried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customThe obtained residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=1:1)