[GRAPHICS] By enhancing the leaving group character of benzotriazole via electron-withdrawing substituents such as the 5-chloro or 6-nitro derivatives with the related N,N'-di-tert butoxycarbonyl-1H-benzotriazole-1-carboxamidines, highly efficient reagents are obtained for conversion of primary and secondary amines in solution and in solid phase to diprotected guanidines.