GB566091A - Preparation of sulphonyl guanylureas - Google Patents

Abstract

Sulphonylguanylureas are prepared by subjecting an aliphatic or an aromatic sulphonyl dicyandiamide to a refluxing or heat treatment in an aqueous medium. If desired water may be used alone, or there may also be present an organic solvent such as alcohol dioxane, or the ethyl ether of ethylene glycol. Alternatively, or in addition, an acidic material may be present, such as hydrochloric sulphuric, sulphurous, nitric, formic, acetic or phosphoric acids. In examples: (1) benzenesulphonyl dicyandiamide is refluxed with an aqueous solution of the ethyl ether of ethylene glycol; (2) n-butyl sulphonyl dicyandiamide is hydrolysed with aqueous hydrochloric acid; (3) benzenesulphenyl dicyandiamide is hydrolysed with aqueous hydrochloric acid; (4) p-acetylaminobenzenesulphonyl dicyandiamide is refluxed with aqueous hydrochloric acid; (5) as in example (4), but using aqueous sulphuric acid. Benzenesulphonyl dicyandiamide is prepared by the addition of benzene sulphonyl chloride to a mixture of aqueous potassium hydroxide, acetone and dicyandiamide, followed by acidification with concentrated hydrochloric acid. n-Butylsulphonyl dicyandiamide. Crude n-butyl halides prepared from n-butyl isothiourea hydrobromide and chlorine are added to a mixture of aqueous potassium hydroxide, acetone and dicyandiamide, followed by acidification with concentrated hydrochloric acid. p-Acetylaminobenzenesulphonyl dicyandiamide is prepared by the addition of p-acetylaminobenzenesulphonyl chloride to a mixture of aqueous potassium hydroxide, acetone and dicyandiamide followed by acidification with concentrated hydrochloric acid.