反应详情

Reacting 4-hydroxymethyl-3-methylisothiazole (3.0 g.) with cysteamine hydrochloride (2.8 g.) in 48% aqueous hydrobromic acid (50 ml.) by the procedure of Example 1 gives 3-methyl-4-[(2-aminoethyl)thiomethyl]isothiazole hydrobromide. Treatment of this intermediate with aqueous potassium carbonate, extracting with chloroform, drying the chloroform extract over magnesium sulphate and concentrating gives the free base, 5.0 g. of which is then reacted with methyl isothiocyanate (1.94 g.) in ethanol (25 ml.) under reflux for 30 minutes. The product is purified on a column of alumina and elution with benzene gives N-methyl-N'-[2-((3-methyl-4-isothiazolyl)methylthio)ethyl]thiourea. Reaction of this product by the procedure of Example 121 gives N-cyano-N'-methyl-N"-[2-((3-methyl-4-isothiazolyl)methylthio)ethyl]guanidine.