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The reaction of 5-hydroxy-1,4-naphthoquinone with butylamine in the presence of copper(II) acetate monohydrate on heating resulted in the formation of a mixture of regioisomeric 2,6-and 2,8-bis(butylamino)-5-hydroxy-1,4-naphthoquinones.Naphthoquinone derivatives having hydroxy and amino groups attract interest as potential biologically active substances [1], dyes [2], and organic materials for nonlinear optics [3]. It is known that 5-hydroxy-1,4-naphthoquinone (I, juglone) reacts with amines only at the quinoid ring to give the corresponding 2-and 3-amino derivatives; no examples of introduction of the second amino group into the aromatic ring were reported [1,4].The present study was aimed at synthesizing alkylamino derivatives of juglone by its reaction with butylamine in the presence of copper(II) acetate. Castillo et al. [5] previously showed that the reaction of juglone with butylamine in a two-phase system CH 2 Cl 2 -H 2 O leads to formation of isomeric 2-and 3-butylamino derivatives II and III in 11 and 6% yield, respectively (Scheme 1). We found that the yield of compounds II and III may be raised to 15 and 11%, respectively, by carrying out the reaction in ethanol and that the amination of juglone complex with copper(II) acetate monohydrate Cu(OAc) 2 · H 2 O in ethanol gives a mixture of amines II and III in 57 and 10% yield, respectively. Increased selectivity of the reaction toward 2-butylamino derivative II may be rationalized by enhancement of the electron-withdrawing effect of the oxygen atom on C 4 due to coordination to copper(II) ion, as was observed in the amination of 5,8-quinolinequinone in the presence of metal salts [6].Unlike 3-butylamino derivative III, 2-butylamino-5-hydroxy-1,4-naphthoquinone (II) reacted with excess butylamine (used as solvent) in the presence of Cu(OAc) 2 · H 2 O to give two isomeric products IV and V in which the second alkylamino group is attached to the aromatic ring of naphthoquinone (Scheme 2). Bis-(butylamino) derivatives IV and V were not formed when the reaction was performed in butylamine as solvent in the absence of copper salt or in ethanol in the presence of Cu(OAc) 2 · H 2 O.Presumably, introduction of the second amino group into the aromatic ring in the presence of Cu(OAc) 2 · H 2 O is favored by formation of copper chelate for which a contribution of ana-quinoid structure may be assumed, as for chelates derived from α-hydroxy-and α-aminoanthraquinones [7] and naphthazarin [8]. It is known that naphthoquinones having hydroxy or amino groups in the peri positions with