Patent GB-487233-A (GB)
Title: Process for the manufacture of aromatic sulphonamide-substituted antimony compounds
IPC: C07F9/92
Filed: 1936-12-14
Abstract: Organo-antimony compounds containing a sulphonamide substituent are prepared by reacting a sulphonamide-substituted amine of the benzene series after diazotization with a trivalent antimony compound, and if desired, reducing the resulting stibinic acid to stibine oxide.  The benzene nucleus may be further substituted, e.g. by alkyl groups, hydroxyl or alkoxy groups, -O.CH2.COOH and -O.CH2. CONH2 groups, acyl- or alkyl-amino groups, the -NH.CO.NH2 group and halogen atoms, but not by acid groups such as sulphonic and carboxylic groups. The sulphonamide group, too, may be substituted, e.g. by methyl, ethyl, -CH2.COOH, phenyl, p-aminophenyl and p-acetylaminophenyl radicles. Antimony compounds mentioned are the trioxide, trichloride and hydroxide and tartar emetic.  The reaction is preferably effected in the presence of a polyhydric alcohol such as glycerine and mannitol. The products possess therapeutic properties, the stibinic acids being usually employed in the form of their salts with alkalies or nitrogen bases and the stibine oxides as their salts with alkalies or their complex compounds with materials of the kind described in Specification 419,742.  According to the examples: (1) p-aminobenzenesulphonamide is diazotized and treated with a solution of antimony oxide in hydrochloric acid to which glycerine has been added; the resulting stibinic acid is then reduced in dilute methyl alcoholic hydrochloric acid with sulphurous acid and iodine to p-sulphonamidophenylstibine oxide; the latter may be combined with pyrocatechol-3 : 5-disulphonic acid to give a water-soluble complex compound; (2) p-aminobenzene-sulphonic acid dimethylamide is diazotized and reacted with a solution of antimony oxide in hydrochloric acid; by reduction of the stibinic acid so obtained with stannous chloride or sulphurous acid, p-sulphonic acid dimethylamide-phenylstibine oxide is obtained, which is then converted into its complex compound with pyrogallol-disulphonic acid; p-sulphonic acid monomethylamidephenylstibinic acid may be prepared similarly; (3) 1-amino-2 : 5-dimethylbenzene-4-sulphonamide is treated after diazotization with antimony oxide and the stibinic acid reduced with sulphurous acid to give di-(4-sulphonamide-2 : 5-dimethylphenyl)-stibine hydroxide; (4) p-sulphonamide-o-chlorophenylstibine oxide is prepared by reacting diazotized p-amino-m-chlorobenzene - sulphonamide with antimony oxide and reducing with stannous chloride or sulphurous acid; the preparation of p-sulphonamide-o-methoxyphenylstibinic acid from p-sulphonamido-o-methoxyaniline is also mentioned; (5) m-aminobenzene-sulphonamide is converted as above into m-sulphonamidophenylstibinic acid, which may then be reduced. The use of 1-amino-3-ethylbenzene-4-sulphonic acid monomethylamide as starting material is also referred to.  Sulphonamides.-p - Aminobenzene - sulphonamido-acetic acid is obtained by reacting p-acetylaminobenzene - sulphonic acid chloride with aminoacetic acid and deacetylating the product. Compounds for use in the above process having an aminophenyl or acylaminophenyl group attached to the nitrogen atom of the sulphonamide group are prepared by interaction of an acylaminophenylsulphonic acid chloride with a monoacylated aromatic diamine or a nitroarylamine, followed by complete or partial deacetylation or reduction of the nitro group, see Specification 402,920.  The starting materials containing groups -O.CH2. COOH, -O.CH2.CONH2 and -NH.CO.NH2 are formed when acetanilide substituted by one of these groups is treated with chlorsulphonic acid and ammonia and the acetyl group then split off; alternatively, the correspondingly substituted benzene-sulphonic acids are reacted with phosphorus pentachloride and ammonia. p-Sulphonamide-o-methoxyaniline is obtained by acetylating o-anisidine, causing the product to react with chlorsulphonic acid and ammonia, and splitting off the acetyl group.