| 摘要 |
The invention concerns a process for manufacturing 2,5-diamino-6-nitro-pyridine derivatives having the general formula (I), where R<1> to R<4> stand for hydrogen or for alkyl, hydroxyalkyl, dihyldroxyalkyl, alkoxyalkyl, alkoxycarbonyl, hydroxy- or chlorine-substituted alkoxycarbonyl or aminoalkyl residues or an aminoalkyl residue substituted with alkyl or hydroxyalkyl groups, in which the alkyl groups each contain 1 to 14 carbon atoms or an oxazolidinone ring is formed by R<1> and R<2> or R<3> and R<4>. Also described are new 2,5-diamino-6-nitro-pyridine derivatives and a hair-dyeing agent containing 2,5-diamino-6-nitro-pyridine derivatives which represent yellow-orange to blue-violet nitro dyes for direct application to hair and are physiologically innocuous. |
