An operationally straightforward and efficient benzotriazole-based method for the guanylation of diverse amines by use of the new reagent classes (bis-benzotriazol-1-yl-methylene)amines 13a–13f and benzotriazole-1-carboxamidines 17a–17i is described. The preparation is described for a variety of both acyclic and cyclic 1,2,3-trisubstituted guanidines in high yields.