Studies On Non-Pollution And Economical Synthesis Of 2, 5-Diaminotoluene Products For New Industrialization

Synthetic routes for 2,5-diaminotoluene and its series products (2,5-TDAs) are introduced. Their studies and technical progress are reviewed systematically. Efficient and economical methods of preparing 2,5-TDAs have been chosed by 2 steps reaction from o-toluidine(OT), which is diazo-coupling of OT and reductive hydrogenative cleavage of the azo-compound. Solvable key technology and studing contents are suggested in the development of new hair-dyes and high-morlecular materials. New technologies of clearing production are studied for high-purity 2,5-diaminotoluene sulfate (2,5-TDAS),which is synthesized by diazo-coupling, reductive hydrogenative cleavage from o-toluidine OT. At the same time, the series products: 2,5-diaminotoluene(2,5-TDA), 2,5-diaminotoluene aqueous solution (2,5-TDAaq), 2,5-diaminotoluene hydrochloride (2,5-TDAH) are prepared in high-quality. The results show that the process have the characteristics of short reaction steps, lower cost and pollution, excellent product quality and 67.75% yield. Synthesized 2,5-TDAS has emerged HPLC-purity > 99.8% and the contents of OT and metal < 10ppm. The excellent quality is advanced in the world. Developed recovery techniques for OT and 2,5-TDAS have good economical benefit and it may reduce waste water to be above 40% and cyclo-economy to be practiced. Studied complex and decolorizing methods for waste water pretreatment are very efficient in clear synthesis, it make the waste water colorless, transparent, COD below 2000. Using the technology to substitute current production route has a good prospect in developing 2,5-TDA series products. Last, industrialization scheme (plan) of the new process were designed and production of 2,5-TDAS was tried successfully.