Oxidation of phenosafranin and an excess of aniline gave a novel hydroxylated derivative of pseudo-mauveine. N-Methyl- p-toluidine and bis(4-methylphenyl)amine are efficient building blocks for making mauveine-related chromophores. Their oxidation with K2Cr2O7 is believed to form nitrogen centred radicals which then couple with an aromatic amine by homolytic aromatic substitution of hydrogen. The N-methyl substituent and the p-methyl sub-stituents are essential for the reaction to proceed. N-Methyl substituted chromophores were not demethylated in the reaction or by oxidation with K2Cr2O7 in dilute H2SO4. N-Nitroso-bis(4-methylphenyl)amine rearranges smoothly to the orange compound, (2-nitro-4-methylphenyl)-4-methylphenylamine, when a solution in CH2Cl2 is treated with montmorillonite at room temperature for 24 h. 2,4-Dimethylaniline has been used to make a mauveine homologue. The colour of silk dyed with mauveine chromophores has been compared to the colour of silk dyed with authentic 1862 mauveine.
苯并萘宁和过量苯胺的氧化反应产生了一种新的羟基化假紫红色衍生物。N- 甲基对甲苯胺和双(4-甲基苯基)胺是制造与紫红色有关的发色团的有效构件。据信,它们与 K2Cr2O7 氧化后会形成以氮为中心的自由基,然后通过氢的同解芳香取代作用与芳香胺耦合。N 甲基取代基和 p 甲基取代基对反应的进行至关重要。N 甲基取代的发色团在反应中或在稀 H2SO4 中用 K2Cr2O7 氧化时都不会发生脱甲基反应。将 N-亚硝基-双(4-甲基苯基)胺在 CH2Cl2 中的溶液与蒙脱石在室温下处理 24 小时后,可顺利重排为橙色化合物(2-硝基-4-甲基苯基)-4-甲基苯胺。用淡紫红色发色团染色的丝绸颜色与用正宗 1862 年淡紫红色染色的丝绸颜色进行了比较。