反应详情

In a mixture of 1 volume part of acetone and 10 volume parts of ethanol, there is dissolved 0.100 part of 3,4-dihydro-2-amino-5,6-dihydroxy-1(2H)-naphthalenone hydrobromide and with the addition of 0.0115 part of platinum dioxide and 0.038 part of anhydrous sodium acetate, catalytic reduction is carried out in a current of hydrogen gas. After a substantially stoichiometric amount of hydrogen gas has been absorbed, 0.4 volume part of a 48 % aqueous solution of hydrogen bromide is added. The mixture is filtered and the filtrate is concentrated. A small amount of ethanol is added to the residue and, after the insolubles are removed, the filtrate is concentrated a second time. Finally the residue is recrystallized from acetone. The procedure gives 1,5,6-trihydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene hydrobromide. Melting point: 167° to 169° C.(decomp.)

1. customAfter a substantially stoichiometric amount of hydrogen gas has been absorbed
2. addition0.4 volume part of a 48 % aqueous solution of hydrogen bromide is added
3. filtrationThe mixture is filtered
4. concentrationthe filtrate is concentrated
5. additionA small amount of ethanol is added to the residue
6. customafter the insolubles are removed
7. concentrationthe filtrate is concentrated a second time
8. customFinally the residue is recrystallized from acetone