Method for preparing parafuchsin

The invention belongs to the technical field of dyes, and particularly relates to a method for preparing parafuchsin, which comprises the following steps: by taking 4, 4 ', 4'-triaminotriphenylmethane as a substrate and manganese dioxide as a catalyst, carrying out oxidation reaction under an acidic medium to obtain an intermediate product A, and carrying out alkalization treatment to obtain 4, 4 ', 4'-triaminotriphenylcarbinol. According to the method, the process difficulty of parafuchsin is solved, the 4, 4 ', 4'-triaminotriphenylmethane is converted into the 4, 4 ', 4'-triaminotriphenylcarbinol in a manner of combining the acidic medium and the catalyst, and the product purification is realized by utilizing the solubility difference. 本发明属于染料技术领域，具体涉及一种制备副品红的方法，以4,4',4"三氨基三苯甲烷为底物，以二氧化锰为催化剂，在酸性介质下氧化反应得到中间产物A，经碱化处理，得到4,4',4"三氨基三苯甲醇。本发明解决了副品红的工艺难点，利用酸性介质与催化剂相结合的方式将4,4',4"三氨基三苯甲烷转化为4,4',4"三氨基三苯甲醇，并利用溶解度差异实现产物提纯。