3173-53-3Relevant articles and documents
Free-Radical Halogenations. 5. Reaction of Chlorosulfonyl Isocyanate with Alkanes
Mosher, Melvyn W.
, p. 1875 - 1879 (1982)
The free-radical chain reactions of chlorosulfonyl isocyanate with alkanes can be initiated with either light or thermal initiators.The major products in these reactions are chlorides, with low yields of isocyanates and sulfonyl chlorides.On the basis of tertiary to primary hydrogen selectivity of about 120:1 and the relative reactivities of various substrates toward the abstracting radical from chlorosulfonyl isocyanate, the hydrogen-abstracting radical is suggested to be the NCO radical.
POLYMERIZATION, OXYGENATION AND ISOMERIZATION OF ISOCYANIDES UNDER IRRADIATION
Boyer, Joseph H.,Ramakrishnan, V. T.,Srinivasan, K. G.,Spak, A. J.
, p. 43 - 46 (1981)
Irradiation in the presence of triplet oxygen polymerized both 2,4-dimethoxyphenyl and cyclohexyl isocyanide and photoautoxidized each into the corresponding isocyanate.The aryl, but not the alicyclic, isocyanide also photoisomerized into a cyanide.The consumption of an isocyanide was enhanced in the presence of certain aromatic hydrocarbons, e. g., naphthalene and phenanthrene, but was diminished in the presence of pyrene.Two bisisocyanides were unaffected by the presence of oxygen during irradiation.
Synthesis and biological evaluation of novel 4-(4-formamidophenylamino)-N-methylpicolinamide derivatives as potential antitumor agents
Hu, Min,Meng, Nana,Xia, Yong,Xu, Youzhi,Yu, Luoting,Zeng, Xiuxiu,Zhou, Shuyan
, (2021/06/11)
A novel series of 4-(4-formamidophenylamino)-N-methylpicolinamide derivatives were synthesized and evaluated against different tumor cell lines. Experiments in vitro showed that these derivatives could inhibit the proliferation of two kinds of human cancer cell lines (HepG2, HCT116) at low micromolar concentrations and the most potent analog 5q possessed broad-spectrum antiproliferative activity. Experiments in vivo demonstrated that 5q could effectively prolong the longevity of colon carcinoma-burdened mice and slow down the progression of cancer cells by suppression of angiogenesis and the induction of apoptosis and necrosis.
Production process of cyclohexyl isocyanate
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Paragraph 0013; 0028; 0029; 0030; 0031; 0032; 0033; 0034, (2021/03/11)
The invention discloses a production process of cyclohexyl isocyanate, which comprises the following steps: desorbing phosgenation byproduct hydrochloric acid through a desorption tower, removing water, introducing the generated hydrogen chloride gas into
Supporting-Electrolyte-Free Anodic Oxidation of Oxamic Acids into Isocyanates: An Expedient Way to Access Ureas, Carbamates, and Thiocarbamates
Petti, Alessia,Fagnan, Corentin,van Melis, Carlo G. W.,Tanbouza, Nour,Garcia, Anthony D.,Mastrodonato, Andrea,Leech, Matthew C.,Goodall, Iain C. A.,Dobbs, Adrian P.,Ollevier, Thierry,Lam, Kevin
supporting information, p. 2614 - 2621 (2021/06/27)
We report a new electrochemical supporting-electrolyte-free method for synthesizing ureas, carbamates, and thiocarbamates via the oxidation of oxamic acids. This simple, practical, and phosgene-free route includes the generation of an isocyanate intermediate in situ via anodic decarboxylation of an oxamic acid in the presence of an organic base, followed by the one-pot addition of suitable nucleophiles to afford the corresponding ureas, carbamates, and thiocarbamates. This procedure is applicable to different amines, alcohols, and thiols. Furthermore, when single-pass continuous electrochemical flow conditions were used and this reaction was run in a carbon graphite Cgr/Cgr flow cell, urea compounds could be obtained in high yields within a residence time of 6 min, unlocking access to substrates that were inaccessible under batch conditions while being easily scalable.
Practical one-pot amidation of N -Alloc-, N -Boc-, and N -Cbz protected amines under mild conditions
Hong, Wan Pyo,Tran, Van Hieu,Kim, Hee-Kwon
, p. 15890 - 15895 (2021/05/19)
A facile one-pot synthesis of amides from N-Alloc-, N-Boc-, and N-Cbz-protected amines has been described. The reactions involve the use of isocyanate intermediates, which are generated in situ in the presence of 2-chloropyridine and trifluoromethanesulfonyl anhydride, to react with Grignard reagents to produce the corresponding amides. Using this reaction protocol, a variety of N-Alloc-, N-Boc-, and N-Cbz-protected aliphatic amines and aryl amines were efficiently converted to amides with high yields. This method is highly effective for the synthesis of amides and offers a promising approach for facile amidation.
Dehydrogenative Synthesis of Carbamates from Formamides and Alcohols Using a Pincer-Supported Iron Catalyst
Bernskoetter, Wesley H.,Hazari, Nilay,Mercado, Brandon Q.,Townsend, Tanya M.
, p. 10614 - 10624 (2021/09/02)
We report that the pincer-ligated iron complex (iPrPNP)Fe(H)(CO) [1, iPrPNP- = N(CH2CH2PiPr2)2-] is an active catalyst for the dehydrogenative synthesis of N-alkyl- and N-aryl-substituted carbamates from formamides and alcohols. The reaction is compatible with industrially relevant N-alkyl formamides, as well as N-aryl formamides, and 1°, 2°, and benzylic alcohols. Mechanistic studies indicate that the first step in the reaction is the dehydrogenation of the formamide to a transient isocyanate by 1. The isocyanate then reacts with the alcohol to generate the carbamate. However, in a competing reaction, the isocyanate undergoes a reversible cycloaddition with 1 to generate an off-cycle species, which is the resting state in catalysis. Stoichiometric experiments indicate that high temperatures are required in catalysis to facilitate the release of the isocyanate from the cycloaddition product. We also identified several other off-cycle processes that occur in catalysis, such as the 1,2-addition of the formamide or alcohol substrate across the Fe-N bond of 1. It has already been demonstrated that the transient isocyanate generated from dehydrogenation of the formamide can be trapped with amines to form ureas and, in principle, the isocyanate could also be trapped with thiols to form thiocarbamates. Competition experiments indicate that trapping of the transient isocyanate with amines to produce ureas is faster than trapping with an alcohol to produce carbamates and thus ureas can be formed selectively in the presence of alcohols. In contrast, thiols bind irreversibly to the iron catalyst through 1,2 addition across the Fe-N bond of 1, and it is not possible to produce thiocarbamates. Overall, our mechanistic studies provide general guidelines for facilitating dehydrogenative coupling reactions using 1 and related catalysts.
Preparation method of cyclohexyl isocyanate
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Paragraph 0012-0018, (2020/08/27)
The invention relates to a preparation method of cyclohexyl isocyanate, which is characterized by comprising the following steps: S1: putting raw materials of cyclohexylamine and sufficient toluene solvent into a reaction kettle, and controlling the heating temperature of the reaction kettle to be 80-95 DEG C; S2, adding liquid hydrochloric acid into the reaction kettle in the step S1, controllingthe dropwise adding time to be 2.5-3 hours, and controlling the pH value to be 3-7; S3, after the hydrochloric acid is dropwise added in the S2, and performing heating distillation and dehydration; S4, transferring the product salt in S3 and a toluene solvent into an esterification kettle, then slowly adding triphosgene, and controlling the temperature to be 95-115 DEG C when triphosgene is added; s5, after triphosgene is added in the step S4, carrying out heat preservation reaction for 0.5 h, and meanwhile purging the reactor with nitrogen for 0.5-2.5 h; and S6, after the reaction in the step S5 is finished, carrying out reduced pressure distillation to recover the toluene solvent, and carrying out cyclic utilization to produce the cyclohexyl isocyanate.
Method for preparing cyclohexyl isocyanate from solid phosgene
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Paragraph 0043-0066, (2020/09/23)
The invention provides a method for preparing cyclohexyl isocyanate from solid phosgene. The method comprises the following steps: S1, dissolving the solid phosgene in a solvent; S2, slowly adding thesolid phosgene solution into cyclohexylamine hydrochloride, heating, and carrying out a phosgenation reaction to obtain a crude product of cyclohexyl isocyanate; and S3, separating and purifying to obtain the cyclohexyl isocyanate. According to the method provided by the invention, the cyclohexyl isocyanate is prepared through the reaction of the solid phosgene and the cyclohexylamine hydrochloride, so that the yield of the cyclohexyl isocyanate is guaranteed, the chemical property of the solid phosgene is relatively stable, no obvious toxicity exists, and the method has the advantages of improving the safety and reducing the safety production cost.
Palladium-Mediated CO2 Extrusion Followed by Insertion of Isocyanates for the Synthesis of Benzamides: Translating Fundamental Mechanistic Studies to Develop a Catalytic Protocol
Canty, Allan J.,Donnelly, Paul S.,McKay, Alasdair I.,O'Hair, Richard A. J.,Yang, Yang
, (2020/02/26)
Mechanistic studies of a stoichiometric palladium-mediated ExIn (ExIn = extrusion-insertion) decarboxylative amidation of aromatic carboxylic acids are presented, providing gas-phase and condensed-phase spectroscopic data, as well as theoretical computational evidence for intermediates in a proposed stepwise process. The understanding gained from these mechanistic studies directed the development of a palladium-catalyzed procedure in which benzamides are obtained in good to high yields in a one-pot 30 min microwave irradiation assisted protocol. A combination of experimental data and DFT calculations reveals that certain ligand additives favor the selective formation of benzamides rather than the undesired protodecarboxylation side product.
