91-97-4Relevant articles and documents
Synthesis method for preparing 3,3-dimethyl-4,4-biphenyl diisocyanate by phosgene continuous method
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Paragraph 0028-0065, (2020/07/14)
The invention discloses a synthesis method for preparing 3,3-dimethyl-4,4-biphenyl diisocyanate by a phosgene continuous method. A multistage continuous micro-channel reactor is adopted, 3,3-dimethyl-4,4-biphenyl diamine and phosgene are used as raw materials, the micro-channel reactor is adopted for phosgene continuous production, the reaction time is shortened from several h in the prior art toseveral min and generally does not exceed 20 min, and the reaction efficiency is remarkably improved. The selectivity of the product is obviously improved, the byproduct urea is obviously reduced, andthree wastes are reduced. The whole reaction process is a continuous reaction, the process is simple, reaction conditions are accurately controlled, equipment corrosion is small, and safety is high.The reaction yield is increased and reaches 95-98%, the product purity is greater than 99%, and the production cost is low.
Preparation method of 1,5-naphthalene diisocyanate
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Paragraph 0026-0027; 0028-0029; 0030-0031; 0032-0061, (2019/08/26)
The invention relates to a preparation method of 1,5-naphthalene diisocyanate. The preparation method comprises the steps that a catalyst polyoxometallate and a solvent are added into a reaction container; then raw materials including 1,5-diaminonaphthalene, phenylsilane, an acid-binding agent and a dehydrating agent are added, and the materials are evenly mixed; finally, gaseous carbon dioxide isadded, the materials are stirred magnetically at a certain temperature for sufficient reaction, and the product is obtained. According to the method, an M-Anderson type heteropoly acid serves as a catalyst, the catalyst is mild in required reaction condition, high in specific selectivity, capable of being recycled and environmentally friendly, the cleanness of industrial reaction is improved, theeconomical efficiency of the technology is improved, the manufacturing cost and generation of three wastes are reduced, the environment-friendly pressure is reduced, and industrial production is facilitated.
Synthesis of isocyanates from carbamate esters employing boron trichloride
Butler,Alper
, p. 2575 - 2576 (2007/10/03)
The conversion of carbamate esters to isocyanates and diisocyanates of industrial importance is possible using BCl3 in the presence of Et3N; the reaction is simple in execution and work-up, occurring under mild conditions and affording isocyanates in excellent yields.