- Halogen-Free Synthesis of Carbamates from CO2 and Amines Using Titanium Alkoxides
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A direct synthesis of carbamates from amines and carbon dioxide in the presence of Ti(OR)4 (R=nBu (1), Me (2), Et (3), nPr (4)) was investigated. Aniline was reacted with titanium n-butoxide (1) in the presence of carbon dioxide (5 MPa) to give the corresponding n-butyl N-phenylcarbamate (BPC) in nearly quantitative yield (99 %) within 20 min. Furthermore, 1 could be regenerated upon reaction with n-butanol during water removal. The recovered 1 could then be reused in a subsequent reaction.
- Choi, Jun-Chul,Yuan, Hao-Yu,Fukaya, Norihisa,Onozawa, Syun-Ya,Zhang, Qiao,Choi, Seong Jib,Yasuda, Hiroyuki
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supporting information
p. 1297 - 1300
(2017/06/23)
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- METHOD FOR PRODUCTION OF ISOCYANATE USING COMPOSITION COMPRISING CARBAMIC ACID ESTER AND AROMATIC HYDROXY COMPOUND, AND COMPOSITION FOR TRANSPORT OR STORAGE OF CARBAMIC ACID ESTER
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An object of the present invention is to provide an isocyanate production process, which is free of the various problems found in the prior art, and which uses a composition containing a carbamic acid ester and an aromatic hydroxy compound when producing isocyanate without using phosgene, as well as a carbamic acid ester composition for transferring or storing carbamic acid ester. The present invention discloses an isocyanate production process including specific steps and using a composition containing a carbamic acid ester and an aromatic hydroxy compound, as well as a composition for transfer or storage of carbamic acid ester comprising the carbamic acid ester and the specific aromatic hydroxy compound.
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Page/Page column 61
(2010/02/17)
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- PROCESS FOR PRODUCING ISOCYANATE
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An object of the present invention is to provide a process allowing long-term, stable production of isocyanates at a high yield without the various problems found in the prior art during production of isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a decomposition reaction in the presence of a compound having an active proton and a carbonic acid derivative.
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Page/Page column 53
(2009/09/05)
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- Novel material forming supramolecular structures, process and uses
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The invention relates to novel material, forming supramolecular structures below its transition temperature, which contains at least one C=O and/or C=S group and at least one N—H, O—H and/or S—H group and wherein the material has the structure [in-line-formulae]A(—X—B)n ??(1)[/in-line-formulae] wherein A is a cyclic, aromatic and/or aliphatic group, n being a number of 1 to 4, —X—B is, if n is 2, the same or different, and if n is 3 or 4, the same, partly the same or different and has one of the structures (2) to (4) [in-line-formulae]NH—C(Y)—Y—B ??(2)[/in-line-formulae] [in-line-formulae]—NH—C(Y)—NR—B ??(3)[/in-line-formulae] [in-line-formulae]—Y—C(Y)—NR—B ??(4)[/in-line-formulae] with Y being an Oxygen and/or Sulfur atom, B being an organic group with at least one heteroatom, where the heteroatom is bound to at least two carbon atoms when B is linear or cyclic, and where the heteroatom is bound to at least one carbon atom when B is branched, and R being a Hydrogen atom, a cyclic, aromatic and/or aliphatic group or another B group which is the same or different. The material can be made by reacting at least one isocyanate and/or thioisocyanate with at least one amine, alcohol and/or thiol. Typically, the material is used first below its transition temperature, followed by increasing the temperature to around or above the transition temperature, carrying out a process step and subsequently decrease the temperature below the transition temperature.
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Page/Page column 11-12
(2008/12/08)
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- Method for synthesis of aliphatic isocyanates from aromatic isocyanates
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The invention relates to a method for synthesis of aliphatic isocyanates from aromatic isocyanates in substantially 3 stages. In particular, the invention relates to a method for synthesis of bis{4-isocyanatocyclohexyl}methane (H12MDI) from bis{4-isocyanatophenyl}methane (MDI). More especially, the invention relates to a method for synthesis of H12MDI with a trans-trans isomer content of 30%, preferably of 20%, particularly preferably of 5 to 15%.
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- A New Method for a Kinetic Study of Reactions between Di-isocyanates and Alcohols. Part 1. Symmetrical Di-isocyanates
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A new method of following the kinetics of the uncatalysed reaction between di-isocyanates and alcohols, which allows the determination of the concentration of all the species occurring during the reaction, by means of the high performance liquid chromatography (HPLC), is described.It has been found that the relationship between the unchanged fraction and the fraction that reacts, theoretically inferred for ideal systems (null catalytic effects), is validated over the whole reaction for real systems.This fact is a verification that the reduced time, τ, is a result of the total catalytic effects, and is a surprising simplification of the kinetics of this type of complex process.The following value ratios of the rate constant (R) for the first and the second NCO groups for various di-isocyanates were determined: 4,4'-BDI R = 1.36, 4,4'-BBDI R = 1.30, p-PDI R = 2.57, m-PDI R = 3.07.
- Caraculacu, Adrian A.,Agherghinei, Ion,Gaspar, Mariana,Prisacariu, Cristina
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p. 1343 - 1348
(2007/10/02)
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