protocol to highly functionalised guanidines. Guanidines containing a hydroxy function were constructed in the microwave by regioselective ring opening of epoxides in the presence of ammonium hydroxide giving the primary amines, which then were reacted with isothiouronium salts. Direct coupling of an unsubstituted guanidine with an epoxide in the presence of n-BuLi gave the same product.