2,6-Dimethylaniline CAS 87-62-7

Using m-xylene as resources, it is gotten by mixed acid nitration and also catalytic hydrogenation. The procedure is to cool down m-xylene to 0 ～ 5 ℃, add the cooled down combined acid (56.5% sulfuric acid, 28% nitric acid, 15.5% water) in batches, keep the temperature level at 17 ℃ ～ 25 ℃ for the first time, include 3h. Finished, the second time was added at 17-25 ° C in 2h, the final dropwise temperature was 25-30 ° C, the enhancement was finished within 1h, and after that mixed at 25-30 ° C for 30min, the nitrates were divided and also washed with water, and after that minimized pressure The crude item was obtained by distillation, the fraction at 78-85 ° C/666.5 Pa was distilled again, and also 2,6-dimethylnitrobenzene was acquired by cooling down and also condensation.

2,6-dimethylnitrobenzene is minimized, and iron powder and also hydrochloric acid are utilized for stepwise reduction in the past, and iron powder is slowly contributed to 2,6-dimethylnitrobenzene as well as water down hydrochloric acid remedy, and afterwards refluxed after including 30min, cooling, after that including sodium carbonate to neutralize, adding water for distillation to get an oily option, layering, and also drying the oily layer to acquire an item. Catalytic hydrogenation has been utilized to change iron powder decrease. In the visibility of a stimulant, 2,6-dimethylnitrobenzene goes through catalytic hydrogenation to obtain a crude product, which goes through post-treatment to get a product.

The products generated by this method are 2,6-dimethylaniline as well as 2,4-dimethylaniline, while the share of 2,6-dimethylaniline in the response procedure is tiny, which can not satisfy the manufacturing demands. The manufacturing of 2,6-dimethylaniline by o-toluidine alkylation has become the focal point.

Alkylation technique, that is, making use of o-toluidine and methanol as basic materials, in the presence of a stimulant, the reaction is performed under a certain stress.

In this reaction, in addition to the major item 2,6-dimethylaniline, there are several spin-offs, of which 2,3-dimethylaniline and 2,6-dimethylaniline have comparable frameworks, comparable physical buildings, and steaming factors. The distinction is tiny and also the splitting up is more difficult. Normally, the alkylated catalysts are first separated from other by-products such as o-toluidine as well as tricolidine to get 2,3-dimethylaniline and also 2,6-dimethylaniline with a web content of 98%. The combination of base aniline, the blend is the starting material (in which the content of 2,3-dimethylaniline is 18%) through precision fractionation, the variety of theoretical plates in the entire tower is greater than 80, and the two elements can be totally Isolated to provide 2,6-dimethylaniline.