反应详情

5.68 g. (28.1 mM) of 3-chloro-1,2-benzisothiazole, 1,1-dioxide (prepared as in Example 1), 4.8 g. (28.1 mM) of ethyl-4-aminobutyrate hydrochloride and 7.84 ml. (56.2 mM) of triethylamine are refluxed in 100 ml. of dioxane for one hour. The solvent is evaporated and the residue refluxed in 1% hydrochloric acid for 2.5 hours. The product crystallizes out overnight at room temperature. The product, 4-[(1,1-dioxo-1,2-benzisothiazol-3-yl)amino]butanoic acid is filtered out, washed with water, and recrystallized from 150 ml. water, yield 4.2 g., m.p. 200°-202°.

1. customThe solvent is evaporated
2. temperaturethe residue refluxed in 1% hydrochloric acid for 2.5 hours
3. customThe product crystallizes out overnight at room temperature
4. filtrationThe product, 4-[(1,1-dioxo-1,2-benzisothiazol-3-yl)amino]butanoic acid is filtered out
5. washwashed with water
6. customrecrystallized from 150 ml