反应详情

N-(3-Amino-1H-indazol-5-yl)-3-fluorobenzenesulfonamide can be obtained in the following way: a solution of 0.3 g of N-[5-(3-fluorobenzenesulfonylamino)-1H-indazol-3-yl]benzamide, of 24 ml of ethanol and of 1.08 ml of 37% hydrochloric acid is heated at a temperature in the region of 100° C. for 30 hours. The cooled reaction medium is concentrated under reduced pressure. 20 ml of water, and aqueous sodium hydroxide, to a pH in the region of 11, are added to the residue thus obtained, which is then extracted with three times 25 ml of ethyl acetate. The pooled organic phases are filtered, dried over magnesium sulfate, filtered again and concentrated by evaporation under reduced pressure. The residue thus obtained is purified by chromatography on a silica column with a dichloromethane/methanol (99/1 by volume) mixture as eluent. The solid thus obtained is recrystallized from 5 ml of isopropanol. 0.1 g of N-(3-amino-1H-indazol-5-yl)-3-fluorobenzenesulfonamide is thus obtained, after drying under reduced pressure at 60° C., in the form of a white solid melting at 216° C. (analysis C13H11FN4O2S % calculated C, 50.97; H, 3.62; F, 6.20; N, 18.29; O, 10.45; S, 10.47. % found C, 50.80; H, 3.72; N, 18.14; S, 10.21).

1. customThe cooled reaction medium
2. concentrationis concentrated under reduced pressure
3. addition20 ml of water, and aqueous sodium hydroxide, to a pH in the region of 11, are added to the residue
4. customthus obtained
5. extractionwhich is then extracted with three times 25 ml of ethyl acetate
6. filtrationThe pooled organic phases are filtered
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered again
9. concentrationconcentrated by evaporation under reduced pressure
10. customThe residue thus obtained
11. customis purified by chromatography on a silica column with a dichloromethane/methanol (99/1 by volume) mixture as eluent
12. customThe solid thus obtained
13. customis recrystallized from 5 ml of isopropanol