3-CHLORO-4-FLUOROBENZENESULFONAMIDE synthesis

Yield: 94%

Reaction Conditions:

with ammonia in 1,4-dioxane;water at 5 - 20; for 22 h;

Steps:

3-chloro-4-fluoro-benzenesulphonamide 6.21 ml (42 mmol) 3-chloro-4-fluorobenzenesulphonic acid chloride are placed in 20 ml dioxane and cooled to 5° C. 85 ml (1.14 mmol) ammonia solution in water (25%) are added dropwise, the mixture is stirred for 6 hours at 5° C. and for 16 hours at ambient temperature. Then it is evaporated down until a precipitate settles out. This is suction filtered, washed with water and dried. Yield: 8.30 g (94% of theoretical)

References:

Maier, Udo;Grauert, Matthias;Hoffmann, Matthias;Hoenke, Christoph;Joergensen, Anne T.;Pautsch, Alexander;Brandl, Trixi;Breitfelder, Steffen;Scheuerer, Stefan;Erb, Klaus;Pieper, Michael;Pragst, Ingo US2007/259855, 2007, A1 Location in patent:Page/Page column 17