- Method for synthesizing 1,5-naphthalene diisocyanate
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The invention discloses a method for synthesizing 1,5-naphthalene diisocyanate. The method comprises the following steps: 1) synthesizing 1,5-naphthalene dicarbamate from 1,5-naphthalene diamine and an auxiliary material A; 2) pyrolyzing the 1,5-naphthale
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Paragraph 0034; 0037-0038; 0041-0042
(2019/10/04)
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- METHOD FOR PREPARING ISOCYANATES BY LIQUID-PHASE THERMAL CRACKING
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The present invention discloses a method for preparing isocyanates by liquid-phase catalytic thermal cracking. In this method, in a reaction-rectification thermal cracking reactor, using a catalyst composition comprising a superfine powder metal oxide catalyst and an ionic liquid, an alkyl or aryl dialkylurethane, or multialkylurethane being a reactant is liquid-phase thermal cracked for a reaction time of 0.5-3 h under a reaction temperature of 160-220° C. and an absolute pressure of 1000-8000 Pa so as to prepare the corresponding isocyanate. The invention has the characteristics of low thermal cracking temperature, high yield of target products, relatively simple reaction apparatus and good universality for substrates (the yields of HDI, MDI, TDI, HMDI, NDI and IPDI or the like are all >85%) and the like.
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Page/Page column 4-5
(2011/02/18)
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- Process for the preparation of 5-nitro-3,4-dihydro-1(2H)-naphthalenone, 1,5-naphthalendiamine and 1,5-naphthalendiisocyanate
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A process for the production of 1,5-naphthalene diamine (I) comprises reaction of 4-(2-nitrophenyl)-n-butyronitrile to 4-(2-nitrophenyl)-n-butyric acid. Independent claims are included for: (1) a process for the production of 5-nitro-3,4-dihydro-1(2H)-naphthalinone by reaction of 4-(2-nitrophenyl)-n-butyronitrile to 4-(2-nitrophenyl)-n-butyric acid and; (2) a process for the production of 1,5-naphthalene diisocyanate by phosgenation of 1,5-naphthalene diamine (I).
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- Process for the production of 1,5-naphtylenediisocyanate
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1,5-naphthylenediisocyanate is industrially advantageously produced at high yields by pyrolyzing methyl 1,5-naphthylenecarbamate synthesized by providing 1,5-naphthylenedinitrile as a raw material and carrying out amidation, chlorination and Hofmann rearr
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- Linking metal centres with diimido ligands: Synthesis, electronic and molecular structure and electrochemistry of organometallic ditungsten complexes [{WCl2(Ph2PMe)2(CO)}2(N-X-N)] (X = π-conjugated organic)
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Tungsten(IV) diimido-bridged complexes [{WCl2(Ph2PMe)2(CO)}(μ-N-X-N)] have been prepared via oxidative addition of diisocyanates to two equivalents of [WCl2(Ph2PMe)4]. para-Substituted monoimido complexes [WCl2(Ph2PMe)2(CO)(NC6H 4X-p)] (X = I, Br or C≡CPh) have also been prepared but attempts to couple the X = I complex as a route to diimido-bridged complexes were unsuccessful. All complexes are air-stable crystalline solids and five diimido (N-X-N = p-NC6H4N, p-N-o-MeC6H3N, p-N(o-MeOC6H3C6H3OMe-o)N, 1,5-NC10H6N or m-NC6H4N) and one monoimido complex (X = I) have been characterised crystallographically. All show the same gross structural features, namely a trans arrangement of phosphines and cis chlorides. The central aryl ring generally lies approximately in the Cl2(CO) plane (torsional angles 4.1-26.1°) except for one complex in which the ring lies almost perpendicular to this (torsional angle 80.2°). A series of density functional calculations conducted on model mono- and di-imido tungsten-(VI) and -(V) compounds indicated that the most stable aryl ring orientation is perpendicular to the plane containing the trans phosphines, i.e. as found in all cases except one (N-X-N = p-NC6H4N). The anomaly in the latter may be due to cocrystallisation with chlorobenzene. In order to assess the degree of communication between the tungsten(IV) centres through the highly π-conjugated diimido linkages, electrochemical studies have been carried out. All diimido-bridged complexes show two closely spaced oxidative processes at low temperature indicative of weak electronic communication. The reductive chemistry of the para-phenylene bridged complexes is different from other diimido complexes, displaying two closely spaced reductive processes. Spectro-electrochemical studies have also been carried out on N-X-N = p-NC6H4N, oxidation at +1.2 V leading to CO loss. In order to gain further insight into the nature of the electronic communication between metal centres density functional calculations were carried out and were generally in agreement with the electrochemical results, suggesting that there is at best a weak interaction between the metal centres in these π-conjugated diimido-bridged complexes.
- Hogarth, Graeme,Humphrey, David G.,Kaltsoyannis, Nikolas,Kim, Woo-Sung,Lee, Mo-Yin,Norman, Tim,Redmond, Simon P.
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p. 2705 - 2723
(2007/10/03)
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- Synthesis of isocyanates from carbamate esters employing boron trichloride
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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.
- Butler,Alper
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p. 2575 - 2576
(2007/10/03)
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- Amid group-containing diisocyanates and amide group-containing epoxy resins
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An amide group-containing epoxy resin obtained by reacting an epoxy resin with an amide group-containing diisocyanate obtained by reacting a diisocyanate with a dicarboxylic acid gives a uniform cured article showing high adhesiveness and is usable as an adhesive, a coating composition, and the like.
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- Impregnated porous granules and a polyurethane matrix held within the pores thereof and holding a liquid material for controlled release of liquid material and process therefor
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A composition of matter having a clay porous granule and a polyurethane matrix formed from the polymerization of a polyol and a polyisocyanate and held within the pores of the granule and having uniformly distributed throughout the polyurethane matrix a liquid material, for example, a pesticide and a method for loading a porous granule with the polyurethane and the liquid material by: (a) spraying a porous granule with a liquid composition comprising a polyol, a polyisocyanate and a liquid material to be retained in the porous granule, and (b) polymerizing the polyol and the polyisocyanate to form a polyurethane matrix polymer which has the liquid materials uniformly distributed throughout the polyurethane matrix.
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- Ethylenic silicon compounds and thermoplastic elastomers obtained therefrom
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The invention provides organosilicon compounds of the formula: STR1 in which: N IS 1, 2 OR 3; Each R, which may be identical or different, is a monovalent organic group which contains a carbon-carbon double bond and from 2 to 10 carbon atoms; Each R1, which may be identical or different, is a straight or branched alkyl radical optionally substituted by one or more halogen atoms or cyano groups; an aryl radical or an alkylaryl radical optionally substituted by one or more halogen atoms; R2 is a straight or branched divalent alkylene or alkylidene radical possessing up to 4 carbon atoms; X is a divalent radical consisting of, or containing, at least one hetero-atom selected from oxygen, sulphur and nitrogen atoms, the radical being attached to the radical R2 via a said hetero-atom; G is an organic radical of valency (m+ l) possess from 1 to 30 carbon atoms; m is 1, 2 or 3; And each Y, which may be identical or different, is a functional group selected from: --NO2, STR2 --COOM (where M represents a sodium, potassium or lithium atom); --COOR4 ; STR3 --COCl; --OH; --OR4 ; STR4 --SH; --SR4 ; STR5 --CONH2 ; --CSNH2 ; --CN; --CH2 --NH2 ; --CHO; STR6 --NCO; STR7 wherein R3 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 6 carbon atoms and R4 represents an alkyl radical possessing up to 4 carbon atoms, with the proviso that two Y groups can together constitute an imide group STR8 wherein R5 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 4 carbon atoms. These are useful intermediates in the preparation of disilanes and silicon polymers, in particular of polyethylenic silicon compounds which can be polymerized with an α, ω-dihydrogenopolysiloxane to give thermoplastic elastomers.
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