GB568850A - Guanidine derivatives - Google Patents

Abstract

Sulphonyl guanidines of the formula <FORM:0568850/IV/1> where X is amino or acylamino are prepared by heating a guanidine compound or its hydrate, or a salt thereof, with a weak acid with a paraaminobenzenesulphonamide, or by heating a salt of a guanidine compound with an alkali or an alkaline earth salt of the above sulphonamide. Instead of the guanidine compound and the sulphonamide, there may be employed the preformed salt formed by the reaction of these two components. The reaction is preferably carried out in the presence of a solvent. In the second embodiment above, it is not necessary to use a weak acid, and accordingly the sulphate or hydrochloride may be employed. As weak acids for use in the first embodiment, there may be used the carbonate, acetate, phenate or cresylate. The two latter are particularly suitable since an excess of the phenol or cresol may be used as the reaction solvent. In examples: (1) Sulphanilamide is heated with the gradual addition of guanidine carbonate for half an hour. The product is treated with and then with alkali to precipitate sulphanilyl guanidine. (2) Guanidine carbonate is added to a phenol solution of sulphanilamide and the sulphanilyl guanidine worked up as before. (3) Sulphanilamide is refluxed with guanidine carbonate in aqueous solution and the sulphanilyl guanidine worked up as before. (4) Guanidine nitrate is refluxed with methanolic sodium hydroxide, the guanidine hydrate so obtained is refluxed with sulphanilamide, and the sulphanilyl guanidine worked up as before. (5) Guanidine nitrate is treated with sodium methoxide, the free guanidine so produced is refluxed with sulphanilamide, and the sulphanilyl guanidine worked up as before. (6) A phenol solution of p-acetylaminobenzenesulphonamide and guanidine carbonate is refluxed, treated with sodium hydroxide, and hydrolysed with hydrochloric acid to give sulphanilylguanidine. (7) Methylguanidine sulphate is treated with methyl alcoholic caustic soda and to the solution of methylguanidine hydrate so formed sulphanilamide is added. The methanol is distilled off and replaced by "sextol" and the mixture refluxed. Treatment with hydrochloric acid gives sulphanilyl guanidine. (8) As in example (7), but using a : a -dimethylguanidine sulphate instead of methylguanidine sulphate.