反应详情

15.0 g. (74.4 mM) of 3-chloro-1,2-benzisothiazole 1,1-dioxide (prepared as in Example 1), 10.4 g. (74.4 mM) of glycine ethyl ester, hydrochloride and 20.4 ml. (148.8 mM) of triethylamine are refluxed in 250 ml of dioxane for 2 hours. The dioxane is evaporated and the residue is taken up in chloroform which is washed with water (2 x) and evaporated. The residue 2-[(1,1-dioxo-1,2-benzisothiazol-3-yl)amino]acetic acid, ethyl ester is recrystallized once from 150 ml of methanol/water (1:1) and once from 200 ml. of water to give 2-[(1,1-dioxo-1,2-benzisothiazol-3-yl)amino]acetic acid, ethyl ester as yellow needles, yield 14.35 g., m.p. 166°-167°.

1. customThe dioxane is evaporated
2. washis washed with water (2 x)
3. customevaporated
4. customThe residue 2-[(1,1-dioxo-1,2-benzisothiazol-3-yl)amino]acetic acid, ethyl ester is recrystallized once from 150 ml of methanol/water (1:1) and once from 200 ml