Spermine → 2,4-Dibenzyloxyphenylacetylspermine

To a solution of spermine (1,4-bis [{(3-amino) propyl}amino]butane, 460 mg) in N,N-dimethylformamide anhydride (5 ml) is added a solution of para-nitrophenyl 2,4-dibenzyloxyphenylacetate (100 mg) in N,N-dimethylformamide anhydride (5 ml). The resulting solution is concentrated to dryness under reduced pressure and thereto are added 5 % aqueous sodium hydrogencarbonate solution (0.1 ml) and then water (30 ml). The resulting precipitate is filtered and washed thoroughly with water, followed by drying, to yield crude 2,4-dibenzyloxyphenylacetylspermine (72 mg, yield 64%). 3) To a solution of crude 2,4-dibenzyloxyphenylacetylspermine (72 mg) in acetic acid (5 ml) is added 10% palladium-carbon (50 mg) and then catalytic reduction is carried out in a hydrogen stream for one and half hours. After the reaction is over, the catalyst is removed by filtration and the filtrate is concentrated to dryness under reduced pressure. The residue is subjected to separation and purification by high-performance liquid chromatography (reversed-phase partition column TSK gel ODS-120T manufactured by Toyo Soda Mfg., CO., Ltd.; inner diameter of the column: 7.8 mm, length: 30 mm; resin diameter; 3 μm; column temperature: 40° C.; eluent: water/acetonitrile mixed solvent (98/2, V/V) to which trifluoroacetic acid has been added to final concentration of 0.05% by volume). The solvent is distilled off to yield 2,4-dihydroxyphenylacetyl-spermine trifluoroacetic acid salt (3.0 mg, yield 4.2%).