反应详情

2-[3-(4-hydroxyphenyl)propionylamino]-3-methyl butyric acid methyl ester (200 mg), prepared in Example 9, was dissolved in tetrahydrofuran (10 mL) and treated with 2M lithium hydroxide (1 mL). The resulting mixture was stirred for 18 hours at room temperature. The reaction was neutralized with aqueous hydrochloric acid, extracted with ethylacetate (EtOAc) (100 mL), dried over magnesium sulfate, concentrated under reduced pressure and purified by silica gel column chromatography (column size: 25 mm×150 mm, silica gel 70-230 mesh, eluent: EtOAc) to obtain 160 mg of the title compound. The yield was 84%. The results of analyses of the compound are as follows:

1. extractionextracted with ethylacetate (EtOAc) (100 mL)
2. dry with materialdried over magnesium sulfate
3. concentrationconcentrated under reduced pressure
4. custompurified by silica gel column chromatography (column size: 25 mm×150 mm, silica gel 70-230 mesh, eluent: EtOAc)