Zur Synthese sulfonierter Derivate von 4-Fluoranilin

Article abstract of DOI:10.1002/hlca.19820650212

Syntheses of Sulfonated Derivatives of 4-Fluoroaniline; Synthesis of 2-amino-5-fluorobenzenesulfonic acid (2) was achieved by baking the hydrogen sulfate of 4-fluoroaniline (1).Sulfonation of p-fluoroacetanilide (4) with oleum followed by hydrolysis gave 5-amino-2-fluorobenzenesulfonic acid (3).The same reaction with 1 yielded 3 in an impure state.The structures of 2 and 3 were confirmed by converting the diazonium chlorides derived from 5-fluoro-2-nitroaniline (5) and from 2-fluoro-5-nitroaniline (8) to 5-fluoro-2-nitrobenzenesulfonyl chloride (6) and 2-fluoro-5-nitrobenzenesulfonyl chloride (9), respectively, followed by hydrolysis of 6 to 5-fluoro-2-nitrobenzenesulfonic acid (7), and of 9 to 2-fluoro-5-nitrobenzenesulfonic acid (10), and by final reduction.Compound 10 was also obtained by sulfonation of 1-fluoro-4-nitrobenzene (11) with oleum.