Dimethylbiguanide hydrochloride prepn. - by reaction of hydrogen chloride gas with a conc. soln. of dimethylamine and dicyandiamide in xylene

摘要

Dimethylbiguanide hydrochloride is prepd. by adding progressively initially at room temp., hydrogen chloride gas to a conc. solution of equimolar proportions of dimethylamine and dicyandiamide in an organic solvent, esp. xylene. The reaction is more readily controlled and yields are less likely to be reduced by degradation than in processes in which dimthylamine hydrochloride reacts with dicyandiamine with the application of external heat to initiate the reaction. The prod. is an oral hypoglycaemic agent. Typically, a 96% yield of hydrochloride is obtd. by reaction of HCl gas (365 kg.) with a solution of dimethylamine (450 kg.) and dicyandiamide (840 kg.) in xylene ( 1000 litres).