Patent ID: 6680409
Filing Date: 2004-01-20
Classification: C07C

Abstract:
Process for preparing robenidine and salts thereof, said robenidine and its salts having the general formula in which X is a halogen atom,said process comprising reacting hydrazine hydrate with a cyano compound of the general formula Yâ€”CNâ€ƒâ€ƒII in which Y is a halogen atom or tosyl, in a C1-4-alcohol or a C1-4-alcohol/water mixture as solvent or in an aprotic polar organic solvent, to produce a diaminoguanidine of the general formula in which Y is a halogen atom or tosyl,said diaminoguanidine then being converted directly, without isolation, by reacting with a p-halobenzaldehyde of the general formula wherein X is a halogen atom, in a C1-4-alcohol/water mixture as solvent or in a mixture of water and an aprotic organic solvent, into the robenidine and salts thereof of general formula I.