反应详情

Using 1.91 parts of 5 % palladium-on-carbon, 1.89 parts of 2-cyclohexylamino-5,6-dihydroxy-3,4-dihydro-1(2H)-naphthalenone hydrobromide in 50 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 the filtrate is freeze-dried. The residue is recrystallized from a mixture of ethanol and ethyl acetate, whereby 2-cyclohexylamino-1,5,6-trihydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide is obtained as colorless crystals. Yield 1.38 parts; melting point: 230°-236° C (decomposition).

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