B 1633 (OTTO) B 1633 (Benzotriazol-1-yloxy) tris(dimethylamino)phosphonium hexafluoro phosphate, 97% Cas 56602-33-6 - used as a reagent for peptide coupling, lactonization, selective esterification, amidation of alfa amino acids without racemization and synthesis of magnolamide for antioxidative activity and catalyst for 9-acridinecaroboxamide derivative.