Dye intermediates, also known as intermediates, generally refer to various aromatic hydrocarbon derivatives used in the production of dyes and organic pigments. They are produced from aromatic hydrocarbons such as benzene, toluene, naphthalene and anthracene from coal chemical and petrochemical industries through a series of organic synthesis unit processes (see reaction process). With the development of the chemical industry, the application range of dye intermediates has expanded to the pharmaceutical industry, the pesticide industry, the explosives industry, the information recording material industry, as well as the auxiliary, surfactant, fragrance, plastic, synthetic fiber and other production sectors. There are many varieties of dye intermediates, and hundreds of them are more important. The most important dye intermediates in the early period, such as nitrobenzene, aniline, phenol, chlorobenzene and phthalic anhydride, have developed into important basic organic intermediates due to their wide use and large dosage. More than 10,000 tons. The most important dye intermediates now include o-nitrochlorobenzene, p-nitrochlorobenzene, o-nitrotoluene, p-nitrotoluene, 2-naphthol, anthracene, 1-aminoindole and the like. Starting from the above intermediates, a series of organic synthesis unit processes can be used to prepare various intermediates with complex structures.
