- Preparation method of amide derivative
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The invention provides a preparation method of an amide derivative. The method comprises the following steps: taking hydroxamic acid and an amine or thiol compound as raw materials, sequentially adding alkali and a solvent, carrying out a reaction for 2-7 hours at the temperature of 25-50 DEG C in an SO2F2 atmosphere, and after the reaction is finished, carrying out aftertreatment on a reaction solution to obtain the asymmetric urea compound or thiocarbamate compound. According to the invention, cheap, easily available and environment-friendly SO2F2 is used as an accelerant to efficiently promote the generation of isocyanate intermediates and form C-N and C-S bonds. The generation of isocyanate avoids the use of a large amount of halogen or azide dangerous reagents, so that the compound can be used as a green substitute for standard treatment conditions in Curtius rearrangement and Hofmann rearrangement reactions. The substrate is wide in applicability, and the corresponding asymmetricurea and thiocarbamate compounds can be obtained at a relatively good yield. The operation process is simple and suitable for large-scale preparation.
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Paragraph 0035-0039
(2020/05/30)
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- Molecular iodine-mediated synthesis of thiocarbamates from thiols, isocyanides and water under metal-free conditions
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A simple and practical molecular iodine-mediated method for the efficient construction of thiocarbamates from isocyanides, thiols and water under metal-free and mild conditions has been developed. A variety of thiocarbamates were easily synthesized through this methodology, which has the advantages of simple operation, eco-friendly conditions, good functional group tolerance, and readily accessible raw materials.
- Bao, Wen-Hu,Wu, Chao,Wang, Jing-Ting,Xia, Wen,Chen, Ping,Tang, Zilong,Xu, Xinhua,He, Wei-Min
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supporting information
p. 7025 - 7029
(2018/10/02)
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- Ethyl 2-(tert-Butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma): An Efficient Reagent for the Racemization Free Synthesis of Ureas, Carbamates and Thiocarbamates via Lossen Rearrangement
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Boc-Oxyma (Ethyl 2-(tert-butoxycarbonyloxyimino)-2-cyanoacetate) has been reported previously as an efficient coupling reagent for the synthesis of amides, peptides, esters, thioesters and hydroxamic acids. It is known for its excellent racemization suppression capability, and also as an environment friendly reagent as it generates only Oxyma as solid byproduct that can be recovered easily and recycled for the synthesis of the same reagent. In this update, we report a simple, efficient, environment friendly, chemoselective and racemization free method for the synthesis of ureas, carbamates and thiocarbamates from hydroxamic acids via Lossen rearrangement by using Boc-Oxyma. We have achieved racemization free di- and tri-peptidyl ureas with very good yield by using this protocol. A rigorous mechanistic investigation is also incorporated. (Figure presented.).
- Manne, Srinivasa Rao,Thalluri, Kishore,Giri, Rajat Subhra,Chandra, Jyoti,Mandal, Bhubaneswar
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p. 168 - 176
(2017/01/14)
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- Synthesis of unsymmetrical ureas and S-thiocarbamates under catalyst-free conditions in a [BMIM]BF4 ionic liquid
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Unsymmetrical ureas and Sthiocarbamates were prepared in good to excellent yields by direct condensation of phenylurea with amines and thiols in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) without the addition of any additives. The [BMIM]BF4 ionic liquid is a mild medium and can be recycled and reused several times.
- Hosseinzadeh, Rahman,Tajbakhsh, Mahmood,Aghili, Nora
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p. 175 - 182
(2015/05/27)
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- A selenium-catalysed synthesis of thiocarbamates from nitroarenes, carbon monoxide and thiols under mild conditions
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An improved method for the selenium-catalysed synthesis of thiocarbamates under mild conditions has been developed. With acetone as solvent, the one-pot selenium-catalysed carbonylation of nitroarenes and thiols with carbon monoxide proceeds smoothly at atmospheric pressure and ambient temperature.
- Zhang, Xiao-Peng,Lu, Shi-Wei
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experimental part
p. 589 - 591
(2009/08/15)
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- Synthesis of thiocarbamates from thiols and isocyanates under catalyst- and solvent-free conditions
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A simple and efficient procedure was developed for the synthesis of S-alkyl (aryl) thiocarbamates under solvent-free conditions without the use of a catalyst. The significant features of this protocol are (a) operational simplicity, (b) mild reaction cond
- Movassagh, Barahman,Soleiman-Beigi, Mohammad
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p. 137 - 140
(2008/09/20)
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- Kinetics and mechanism of the anilinolysis of S-aryl N-arylthiocarbamates in acetonitrile
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The aminolysis reactions of S-aryl N-arylthiocarbamates (YC 6H4NH-C(=O)-SC6H4Z, 1) with anilines in acetonitrile are studied. The reaction rates are more influenced by the nucleophilicity of the nucleophile than the nucleofugality of the leaving group, but the change In the effective charge from reactants to the TS for formation of the tetrahedral intermediate is slightly greater in the leaving group (βz from-0.07 to -0.14) than In the nucleophile (βx = 0.04-0.12). The magnitude of the Broensted coefficients are in the range of values that are consistent for a stepwise mechanism with rate-limiting formation of the zwitterionic tetrahedral intermediate. Signs of cross-interaction constants, ρxy (>0), ρxz (>0) and ρyz (0), are all consistent with a stepwise mechanism. It Is concluded that the change of the amine from benzylamines to anilines causes a shift of the aminolysis mechanism from a concerted to a stepwise process. Copyright
- Sung, Dae Dong,Jang, Hee Man,Jung, Dae Il,Leeb, Ikchoon
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experimental part
p. 1014 - 1019
(2009/10/26)
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- One-pot direct synthesis of thiocarbamates from aniline, carbon monoxide, and thiols catalyzed by selenium
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Catalyzed by selenium, oxidative carbonylation of aniline and thiols with carbon monoxide and oxygen affords the corresponding thiocarbamates mostly in moderate to good yields under solvent-free conditions at ambient temperature. Copyright Taylor & Franci
- Zhang, Xiaopeng,Lu, Shiwei
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p. 3291 - 3299
(2008/02/12)
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- A novel one-pot solvent-free, triethylamine-assisted, selenium-catalyzed synthesis of thiocarbamates from nitroarenes, carbon monoxide, and thiols
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A novel one-pot solvent-free synthesis of a series of thiocarbamates is reported. Nitroarenes, carbon monoxide, and thiols are the starting materials, with cheap element selenium as catalyst; this method offers a simple access to thiocarbamates mostly in moderate to good yields. The selenium catalyst can be easily recovered and recycled. Georg Thieme Verlag Stuttgart.
- Zhang, Xiaopeng,Lu, Shiwei
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p. 1535 - 1538
(2007/10/03)
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- A new one-pot synthesis of thiocarbamates from isocyanates and disulfides in the presence of Zn/AlCl3 system
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A novel method has been developed for the synthesis of S-alkyl(aryl) thiocarbamates. The route involves, first, the formation of zinc thiolates by reductive cleavage of disulfides in the presence of Zn/AlCl3 system; then subsequent reaction of
- Movassagh, Barahman,Zakinezhad, Yousef
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p. 1330 - 1331
(2007/10/03)
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- A new and facile route for the synthesis of thiocarbamates from aniline, carbon monoxide, and thiols mediated by selenium
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A new and facile route for the synthesis of thiocarbamates was reported. Mediated by selenium, aniline reacts very readily with carbon monoxide and thiols in the presence of triethylamine, to afford the corresponding thiocarbamates mostly in moderate to excellent yields under mild reaction conditions. Selenium can be easily recovered and recycled. Copyright
- Zhang, Xiaopeng,Lu, Shiwei
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p. 606 - 607
(2007/10/03)
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- Nucleophilic Substitution Reactions of Aryl N-Phenyl Thiocarbamates with Benzylamines in Acetonitrile
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The aminolysis reactions of aryl N-phenythiocarbamates (PhNHC(=O)SC 6H4Z; 3b) with benzylamines (XC6H 4CH2NH2) acetonitrile are studied. Rates are much faster than the corresponding reactions of aryl N-phenylcarbamates (PhNHC(=O)OC6H4Z; 3a). The rate increase from 3a to 3b is greater than that expected from substitution of thiophenoxide for phenoxide leaving group in the stepwise aminolysis reactions of esters. This large rate increase and the similar change in the aminolysis rates that are reported to occur from aryl ethyl carbonate (EtOC(=O)OC6H4Z; 2a) to aryl ethylthiocarbonate (EtOC(=O)SC6H4Z; 2b) lead us to conclude that the aminolysis of 3b proceeds by a concerted mechanism in contrast to a stepwise process for 3a. The negative ρxz values (-0.63) and violation of the reactivity-selectivity principle (RSP) support the proposed mechanism. The large βx values (1.3-1.5) obtained are considered to indicate a large degree of bond making in the transition state, which is consistent with the relatively large kinetic isotope effects (k H/kD > 1.0) observed.
- Oh, Hyuck Keun,Park, Jie Eun,Sung, Dae Dong,Lee, Ikchoon
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p. 3150 - 3153
(2007/10/03)
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- N-Nitroso Compounds. IV. Reaction of N-Nitrosourea with Thiol. A New Synthesis of Thiocarbamic S-Esters
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Thirteen thiocarbamic S-esters have been prepared in good yield by the reaction of thiol with substituted N-methyl-N-nitrosourea in anhydrous acetonitrile.
- Yoshida, Kitaro,Isobe, Masayoshi,Yano, Kazuyuki,Nagamatsu, Kazuo
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p. 2143 - 2144
(2007/10/02)
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- The E1cB Mechanism for Thiocarbamate Ester Hydrolysis: Equilibrium and Kinetic Studies
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The alkaline hydrolyses of a series of S-aryl thiocarbamate esters have been measured and the mechanism confirmed to be dissociative.Equilibrium constant for the synthesis of thiocarbamates from thiol and isocyanic acid have been obtained for aqueous media using both kinetic and analytical techniques.Hammett and Broensted parameters for the equilibrium reaction indicate that there is less positive effective charge on the sulphur in the thiocarbamate compared with that on the oxygen in the oxygen analogue.Theoretical arguments are advanced to show that the dissociative reactions of simple carbamate anions involve a planar geometry of the paticipating atoms.
- Bourne, Nicholas,Williams, Andrew,Douglas, Kenneth T.,Penkava, Thomas R.
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p. 1827 - 1832
(2007/10/02)
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