Patent GB-882090-A (GB)
Title: New sulphamoyl benzamides and processes for the production thereof
Filed: 1959-02-26
Abstract: The invention comprises compounds of the formula <FORM:0882090/IV (b)/1> (wherein R1 is an alkyl, alkenyl, hydroxyalkyl, cycloalkyl, aryl, aralkyl or heterocyclic radical which may be substituted by halogen atoms or alkyl, alkoxy or alkylmercapto groups; R2 is hydrogen or an alkyl, alkenyl, hydroxyalkyl, alkoxyalkyl or p aralkyl radical; or R1 and R2 together with the nitrogen atom to which they are attached may represent a saturated heterocyclic residue; X is a halogen atom, an alkyl, alkoxy or alkanoyloxy group containing at most 4 carbon atoms or a hydroxyl group; and Y is a hydrogen or halogen atom or an alkyl or alkoxy group containing at most 4 carbon atoms) and the preparation thereof (1) by reacting a reactive functional derivative, such as a halide or ester, of an appropriately substituted 3-sulphamoyl-benzoic acid with an amine NHR1R2; or (2) for compounds wherein R1 is not a hydroxyalkyl radical and R2 is not hydrogen or a hydroxyalkyl radical, by reacting a salt of an appropriately substituted 3-sulphamoyl-benzoic acid with an N-halogencarbonyl derivative of the appropriate amine; or (3) for compounds wherein neither R1 nor R2 is a hydroxyalkyl radical, by reacting the appropriate sulphohalides with ammonia; or (4) for compounds wherein X is a halogen atom or a hydroxy or alkoxy radical, by heating the corresponding diazonium salts with, respectively, the appropriate copper halide and water, an aqueous strong acid or the appropriate alkanol. When X in the products is an alkanoyloxy group, processes (1), (2) or (3) may be combined with the further step of hydrolysis to form the corresponding hydroxy compounds.  Many examples are given and extensive lists of suitable starting materials are also provided.  Carboxylic acids of the formula <FORM:0882090/IV (b)/2> are prepared, for example, by sulphonating or chlorosulphonating the appropriately substituted benzoic acids, if necessary converting the substituted 3-sulphobenzoic acids into dihalides and partially hydrolysing them, and then reacting the 3-chlorosulphonyl benzoic acids with ammonia; or by nitrating appropriately substituted benzoic acids, reducing the substituted 3-nitrobenzoic acids obtained, diazotizing the resulting substituted 3-amino-benzoic acids, decomposing the diazonium chlorides with sulphur dioxide in presence of copper chloride and reacting the substituted 3-chlorosulphonyl-benzoic acids so obtained with ammonia. Amides of the formula <FORM:0882090/IV (b)/3> are prepared, for example, by chlorosulphonation of the appropriately substituted benzamides; or by nitration of such benzamides, reduction of the substituted 3-nitro-benzamides obtained, and then diazotization of the substituted 3-amino-benzamides obtained and decomposition of the diazonium chlorides with sulphur dioxide; or by sulphonation of the said benzamides and reaction of the resulting substituted 3-sulpho benzamides with a halogenating agent.  Examples of these three processes are also given.  4-chloro-3-sulphamoyl-benzoyl chloride is prepared from the corresponding acid and thionyl chloride.