110 mg of the material (2) shown in Table 2 was dissolved in 12 ml of dichloromethane (DCM) (Wako Pure Chemical). 80 mg of Boc-Dap-OH (Bachem) was added to the solution, and then 6 ml of triethylamine (TEA) (Wako Pure Chemical) was added little by little, followed by stirring at room temperature overnight. After the reaction was over, the reaction solution was subjected to evaporation by an evaporator to remove the solvent, supplied with 5% NaHCO3(aq), and further supplied with 0.3 N HCl until the solution got acidic to form a precipitate, which was then filtered by suction and dried in a desiccator. Boc-Dap-OH and the compound (3) thus obtained, 2-tert-butoxycarbonylamino-3-(10-methyl-9-oxo-9,10-dihydro-acridine-2-sulfonylamino)-propionic acid were analyzed to get their respective 1H-NMR data. The results are shown in FIG. 6 and FIG. 7. The product was further purified by silica gel column chromatography to give a substance, which was then analyzed to give the 1H-NMR data. The result was shown in FIG. 8.
