1: 4-(dihydroxyboryl)benzoic acid With N,N-diethanolaminomethyl polystyrene in tetrahydrofuran T=20°C; Solid phase reaction; 2 h; 2: N-butylamine With benzotriazol-1-ol; diisopropyl-carbodiimide in N,N-dimethyl-formamide T=20°C; Solid phase reaction; 6 h; 3: With water; acetic acid in tetrahydrofuran T=20°C; Solid phase reaction; 1 h;