反应详情

In the presence of 1.53 parts of 5% palladium-on-carbon, 1.5 parts of 2-cyclobutylamino-5,6-dihydroxy-3,4-dihydro-1(2H)-naphthalenone hydrobromide in 200 volume parts of water is subjected to catalytic reduction at ordinary temperature and pressure. When a stoichiometric amount of hydrogen has been absorbed, the reaction mixture is filtered to remove the catalyst and filtrate is freeze-dried. The residue is recrystallized from a mixture of water, ethanol and ethyl ether, whereby 2-cyclobutylamino-1,5,6-trihydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide is obtained as colorless crystals. Yield 0.65 part; melting point: 190°-200° C (decomposition).

1. customWhen a stoichiometric amount of hydrogen has been absorbed
2. filtrationthe reaction mixture is filtered
3. customto remove the catalyst and filtrate
4. customis freeze-dried
5. customThe residue is recrystallized from a mixture of water, ethanol and ethyl ether