Patent GB-553601-A (GB)
Title: Process for obtaining sulphonamide derivatives
Filed: 1941-08-06
Abstract: 553,601. Sulphonamide compounds. PARKE, DAVIS & CO. Aug. 6,1941, No. 10001. Convention date, Aug. 3, 1940. [Class 2 (iii)] 4:4<SP>1</SP> - Diaminodiphenylsulphone - 2 - sulphon amide is prepared by reacting sodium p-acetaminobenzenesulphinate with 2-chloro-5-nitrobenzenesulphonamide and subjecting the resulting 4 - acetamino - 4<SP>1</SP> - nitrodiphenylsulphone - 2<SP>1</SP> - sulphonamide to reduction and hydrolysis in either order. Examples are given, according to which the intermediate product is first reduced with iron dust and acetic acid and then hydrolyzed with sodium hydroxide solution, or first hydrolyzed with acetic-hydrochloric acid solution and then hydrogenated under pressure in the presence of Raney nickel catalyst. The Specification as open to inspection under Sect. 91 also describes the preparation of 4:4<SP>1</SP>- diaminodiphenylsulphone - 2 - sulphonamide and its alkali metal salts in which the amino and sulphonamide groups may contain acyl substituents, and also refers to methods which comprise the oxidation of a diaminosulphide. The products are stated to be especially useful as internal antiseptics. Further examples describe the preparation of (1) theunsubstituted diaminodiphenylsulphone - sulphonamide by reducing 4:4<SP>1</SP> - dinitro-diphenylsulphide - 2 - sulphonic acid to the diamino compound with iron and acetic acid, diacetylating, oxidizing with hydrogen peroxide to the sulphone, converting the sulphonic acid group into sulphonamide by treatment first with phosphorus pentachloride and then with ammonia, and finally hydrolyzing off the acetyl groups ; (2) 4:4<SP>1</SP> - diacetaminodiphenylsulphone - 2 - sulphonamide by acetylating 41-acetamino-4- aminodiphenylsulphone - 2 - sulphonamide ; (3) 4:4<SP>1</SP> - diacetaminodiphenylsulphone - 2 - N - acetylsulphonamide by treating 4:4<SP>1</SP>-diaminodiphenylsulphone-2-sulphonamide with boiling acetic anhydride ; by heating with caustic soda solution, the sodium salt of 4:4<SP>1</SP>-diaminodiphenysulphone - 2 - N - acetylsulphonamide is obtained; (4) 4:4<SP>1</SP> - diacetaminodiphenylsulphone 2 - N - nicotinylsulphonamide by boiling 4:4<SP>1</SP> - diacetaminodiphenylsulphone - 2 - sulphonamide with nicotinyl chloride in pyridine ; on heating with caustic solution, the acetyl groups are removed. Other acids whose residues may be introduced into the amino and sulphonamide groups of the starting material are propionic, butyric, oleic, linoleic, palmitic, mandelic, benzoic, salicylic, cinnamic, lactic, malic, maleic, phthalic, citric and gluconic acids ; in the case of acids containing hydroxyl groups it may be necessary to protect the group before forming the acid chloride usually employed. This subject-matter does not appear in the Specification as accepted. Sodium p-acetaminobenzenesulphinate is obtained by treating p-acetaminobenzene sulphonyl chloride with sodium sulphite. 2 - chloro - 5 - nitrobenzenesulphonamide is prepared by sulphonating p-chloronitrobenzene, converting the resulting 2-chloro-5-nitrobenzene sulphonic acid into the sulphonyl chloride by means of chlorsulphonic acid and reacting with ammonium hydroxide.