Environment-friendly 1, 5-diamido-naphthlamine production technique

Abstract

The invention discloses an environment-friendly 1, 5-diamido-naphthlamine production technique. The environment-friendly 1, 5-diamido-naphthlamine production technique sequentially includes (A), adding raw materials including 1,5-dinitronaphthalene, reaction solvent N, N-dimethylformamide (DMF) and a Pd / C (palladium / carbon) catalyst into a reaction kettle, and performing catalytic hydrogenation reaction at the reaction temperature of 25-50 DEG C and under the reaction pressure of 0.1-0.5 MPa; (B), after reaction, recycling a solid catalyst in reaction liquor by a nitrogen filter pressing method, obtaining a solid crude product after distilling of filter liquor, and obtaining a high-purity 1, 5-diamido-naphthlamine product after washing and filtering of the crude product; (C), mixing distillation cut obtained by distillation and washing liquor after washing, recycling DMF and water by a vacuum rectification method. The 1, 5-diamido-naphthlamine production technique is mild in reaction condition, high in reaction yield, high in purity of the obtained 1, 5-diamido-naphthlamine product, low in production energy consumption and simple and efficient in recycling process of catalyst and solvent; recycled catalyst, solvent and water can be utilized cyclically, so that the production technique is environment friendly.

Description

technical field [0001] The invention belongs to the field of organic chemical technology, and in particular relates to an environment-friendly production technology of 1,5-diaminonaphthalene. Background technique [0002] 1,5-diaminonaphthalene is an important organic chemical intermediate, widely used in the dye industry, for the preparation of azo dyes, and an important polyurethane material intermediate, which can be used to prepare 1,5-naphthalene diisocyanate , and then prepare advanced polyurethane elastomer. [0003] The traditional reduction techniques for preparing 1,5-diaminonaphthalene with 1,5-dinitronaphthalene mainly include iron powder reduction method and electrochemical reduction method, DE2523351, CN98371188.1, CN94110239.4, CN101187031A and other documents has been described in detail. The iron powder reduction method is to heat and reduce 1,5-dinitronaphthalene in xylene with iron powder, water and acetic acid. The reaction yield of this method is low, ...

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Problems solved by technology

Documents CN101544569A and CN101575295A have described this method, using 1,5-dinitronaphthalene as a raw material, using Pd / C as a catalyst, in organic compounds such as aniline, ethanol, isopropanol, tetrahydrofuran, ethyl acetate or p-xylene Reaction in the solvent prepares 1,5-diaminonaphthalene, according to the record in the above-mentioned literature, the yield in the reaction filtrate some can reach more than 90%, but the reaction needs to be carried out under higher reaction temperature and hydrogen pressure, simultaneously , how to be beneficial to industrial application, and finally can be separated easily and conveniently to obtain high-purity 1,5-diaminonaphthalene products, but there is no report in the above documents

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