- Interpretation of the mechanism of 3,3′-dichloro-4,4′-diamino diphenylmethane synthesis over HY zeolites
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Catalytic activities of zeolites HY, Hβ and HZSM-5 in the heterogeneous synthesis of 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA) fromo-chloroaniline and formaldehyde were pre-screened in an autoclave, and HY demonstrated better performance than others. Kinetic behaviors of MOCA synthesis over HY(11) were further investigated in a fixed bed continuous flow reactor, and under the conditions of the catalyst bed volume = 20 mL (8.14 g),n(o-chloroaniline) : n(HCHO) = 4 : 1, LHSV = 3.5 h?1, 0.5 MPa and 443 K, HCHO conversion and MOCA selectivity steadily fluctuated at high levels of 90-92% and 75-77% during 16 h, respectively. Catalysts were characterized by BET, NH3-TPD and XRD, products analyzed by HPLC, and reaction intermediates identified by LC/MS and1H NMR. The mechanism of MOCA synthesis has been interpreted in detail, which also suggested that deposition of basic intermediates on active sites and accumulation of polymeric by-products in pore channels of the catalyst could cause significant decay of HY(11) activity and selectivity under severe conditions. Supplementary tests on catalyst regeneration confirmed that the acidity and surface area of spent HY(11) could be well recovered after burning off the deposited by-products.
- Ruan, Xiao,Wang, Qiang,Wei, Feng,Yang, Li,Zhao, Yingxian
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- Continuous synthesis process of 3, 3'-dichloro-4, 4'-diaminodiphenyl methane
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The invention provides a continuous synthesis process of 3, 3'-dichloro-4, 4'-diaminodiphenyl methane, and relates to the technical field of compound synthesis. The synthesis process comprises the steps of salifying condensation, rearrangement reaction, neutralization and separation, washing and liquid separation, and vacuum drying. According to the process, the addition amounts of the three raw materials are accurately adjusted to control the ratio, continuous reaction and post-treatment operations are realized, particularly, the salifying condensation step is combined with sampling at different positions of the reactor to perform high-performance liquid phase detection, materials are discharged to the next procedure in time, so that the phenomena of reaction system residues in each stage, side reaction deterioration of intermediates and reduction of product purity are avoided; in the neutralization and separation step, sodium salt is filtered through a filter plate, so that the water consumption for subsequent washing and liquid separation is reduced, and the cost is greatly saved; and according to the invention, continuous synthesis of MOCA is realized, and the synthesis efficiency of MOCA and the yield and purity of the product are improved.
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Paragraph 0032-0051
(2021/05/01)
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- Method for continuously preparing 3, 3'-dichloro-4, 4'-diaminodiphenyl methane
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The invention relates to a method for continuously preparing 3, 3'-dichloro-4, 4'-diaminodiphenyl methane, which comprises the following steps: respectively continuously and simultaneously dropwise adding a hydrochloric acid solution, o-chloroaniline and a formaldehyde aqueous solution into a primary reaction kettle to carry out salification and condensation reaction; carrying out continuous rearrangement reaction and neutralization reaction by adopting a double-kettle switching mode; and carrying out continuous oil-water separation and continuous washing on the product. The purity and chromaticity stability of the obtained MOCA product are obviously improved. According to the invention, the ubiquitous problems of easy discoloration of MOCA and unreacted o-chloroaniline due to long-time heat storage, unstable chroma of the MOCA product, limited capacity scale and the like in the prior art are effectively solved, moreover, the synthesis process is automatically and continuously controlled, the overall production efficiency is remarkably improved, the acid consumption, the alkali consumption and the salt-containing wastewater discharge amount are remarkably reduced, the environmentalprotection effect is remarkably enhanced, the operation is simple, the economic cost is low, the capacity scale of a single production line is large, and the method is suitable for popularization andapplication.
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Paragraph 0038; 0040; 0046; 0048-0052; 0054-0058; 0060-0064
(2020/09/30)
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- Method of synthesizing 3,3'-dichloro-4,4'-diaminodiphenylmethane by using heteropoly acid
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The invention discloses a method of synthesizing 3,3'-dichloro-4,4'-diaminodiphenylmethane by using heteropoly acid. The method comprises the following steps: (1) adding o-chloroaniline and a formaldehyde solution into a reaction vessel in a room temperature; (2) adding a heteropoly acid catalyst into the reaction vessel; (3) under a magnetic stirring condition, performing heating to ensure the temperature in a range of 50-160 DEG C and performing a reaction for 0.5-8 hours; (4) after the reaction is completed, performing cooling to the room temperature, performing pumping filtration, removing the filtrate, and collecting the filter cake; and (5) performing recrystallization on the obtained filter cake by using an organic mixed solvent, and performing filtering and drying to obtain the solid heteropoly acid synthesized 3,3'-dichloro-4,4'-diaminodiphenylmethane. The method provided by the invention is mild in condition, simple in operation, high in yield and good in product quality.
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Paragraph 0026-0027; 0028-0033; 0034-0041; 0042-0045
(2018/04/01)
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- By using micro-reactor preparation 4, 4' - diamino diphenylmethane derivatives (by machine translation)
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The invention discloses the use of micro-reactor for preparing the 4, 4 '- diamino diphenylmethane derivatives, water, inorganic acid of the reaction liquid and the formaldehyde solution respectively through the advection pump conveying to the micro-reactor in the two inlets, in micro-contacting in a reactor, mixing and reaction, then cooling, sodium hydroxide aqueous solution, a white precipitate is separated out, filtering, drying, to obtain 4, 4' - diamino diphenylmethane derivatives (MDA, MDT or MOCA) crude, recrystallized with ethanol, filtering, drying, to get the pure product. The invention adopts the micro-reactor technology to achieve a 4, 4' - diamino diphenylmethane derivatives of continuous preparation, easy large-scale production; the reaction speed, reaction time is greatly shortened. (by machine translation)
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Paragraph 0048; 0049; 0050; 0051-0055; 0068; 0069
(2017/08/31)
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- Continuous preparation of solid acid catalysis 4, the 4 [...] -diamino diphenylmethane derivatives (by machine translation)
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The invention discloses a continuous preparation of solid acid catalysis 4, the 4 [...] -diaminodiphenylmethane derivative method, the method to aniline derivatives as raw materials with formaldehyde, in one stage or two stage fixed-bed reactor to conduct the condensation reaction of the solid acid catalysis of the reaction, the reaction liquid airspeed is 2-9h -1, obtain 4, the 4 [...] -diamino diphenylmethane derivatives (MDA, MDT, MOCA). The invention uses a solid acid Hβ, HY, HZSM-5 molecular sieve to replace the hydrochloric acid, the traditional inorganic acid catalyst such as sulfuric acid, the reaction is carried out continuously, the method of the invention process is simple, short reaction time, the productivity is high, high yield, no corrosion to equipment, environmental protection, especially suitable for continuous industrial production. (by machine translation)
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Paragraph 0037; 0062
(2016/10/08)
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- Highly regioselective para-methylthiolation/bridging methylenation of arylamines promoted by NH4I
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Aryl methyl thioethers and methylene-bridged arylamines were synthesized via highly regioselective para-methylthiolation/bridging methylenation of arylamines using DMSO as the methylthio or methylene source in the presence of NH4I under metal-free conditions. For the substrates with both electron-donating and electron-withdrawing substituents, the reaction proceeded smoothly and gave moderate to good yields.
- Xu, Yinfeng,Cong, Tiantian,Liu, Ping,Sun, Peipei
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supporting information
p. 9742 - 9745
(2015/10/05)
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- Functionalized Photoreactive Compounds
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The present invention concerns functionalized photoreactive compounds of formula (I), that are particularly useful in materials for the alignment of liquid crystals. Due to the adjunction of an electron withdrawing group to specific molecular systems bearing an unsaturation directly attached to two unsaturated ring systems, exceptionally high photosensitivities, excellent alignment properties as well as good mechanical robustness could be achieved in materials comprising said functionalized photoreactive compounds of the invention.
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- Antifungal cyclohexapeptides
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The present invention is directed to novel carba cyclohexapeptide compounds of the formula STR1 where all substituents are defined herein, which are useful as antifungal agents and for the treatment of Pneumocystis carinii infections. Compositions containing the compounds of the invention are also disclosed.
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- Benzotriazole Mediated Synthesis of Methylenebisanilines
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Methylenebisanilines and methylenebis(N,N-dialkylaniline)s are prepared by the reactions of 1-hydroxymethylbenzotriazole with anilines and with N,N-dialkylanilines under acidic conditions.Isolation of the intermediate 4-(benzotriazol-1-ylmethyl)anilines and the N,N-dialkyl analogues and their reactions with anilines allow the efficient preparation of both symmetrical and unsymmetrical members of both product classes.
- Katritzky, Alan R.,Lan, Xiangfu,Lam, Jamshed N.
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p. 341 - 346
(2007/10/02)
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