- Amide-assisted rearrangement of hydroxyarylformimidoyl chloride to diarylurea
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A novel amide-assisted rearrangement reaction of hydroxybenzimidoyl chloride has been established for the efficient synthesis of 1,3-diphenylurea derivatives. A variety of electronically and sterically different 1,3-diphenylurea derivatives can be obtained in good to excellent yields, and a proposed reaction mechanism is also presented.
- Jin, Yi,Liu, Xiaoyu,Song, Xizhong,Yu, Wei
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supporting information
(2021/11/11)
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- Investigation of active sites using solid state 27Al and 31P MAS NMR in ceramic amorphous aluminophosphate materials prepared from different potassium salts of phosphate for the synthesis of diphenyl urea derivatives
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Ceramic amorphous aluminophosphate (CAmAlP) catalysts were prepared by precipitation method using different phosphate salts of potassium such as KH2PO4, K4P2O7 and K2HPO4 as well as H3PO4. The prepared materials were characterized by PXRD, FT-IR, XPS, SEM, BET Surface area, NH3-TPD, 27Al NMR and 31P NMR analytical methods. The catalytic activity of the materials was checked in the synthesis of diphenyl urea (DPU) from aniline and diethyl carbonate, under refluxing conditions. Further, the general application of the catalysts was tested using various substituted anilines. The recyclability of the catalysts was also studied. Uncertainties in percentage yields were calculated to check the reproducible surface properties. The P-XRD, BET Surface area and NH3-TPD results indicated that the materials were amorphous with mesoporous texture, surface areas and acidities in the range 200–260 m2/g and 0.4–0.7 mmol/g respectively. 27Al NMR studies revealed that Al is present in three different coordination states such as tetrahedral, pentagonal and octahedral. The relative percentages of these Al sites depends on the type of the potassium precursor phosphate salt used. Both tetrahedral and pentagonal Al sites in conjunction with each other represented catalytically active sites. An increase in the pentagonal sites contributed to additional increments to the catalytic activity of CAmAlP. The catalyst prepared from KH2PO4 was found to be the best and demonstrated 96% DPU yield.
- Harish,Kathyayini,Baby, Bindhu,Nagaraju
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- Preparation method of symmetric urea compound
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The invention discloses a preparation method of a symmetric urea compound, which comprises the following steps: by using a hydroxamic acid compound as a raw material, sequentially adding an alkali anda solvent, reacting at 25-50 DEG C for 1-7 hours in an SO2F2 atmosphere, and carrying out aftertreatment on the reaction solution to obtain the symmetric urea compound. According to the invention, cheap, easily available and environment-friendly SO2F2 is used as an accelerant to efficiently promote the generation of an isocyanate intermediate to form a C-N bond. 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 amine source in the final product only comes from hydroxylamine, and no additional amine needs to be added, so that the substrate is wide in applicability, and the correspondingsymmetric urea compound can be obtained at a relatively good yield. The operation process is simple, the aftertreatment only needs filtering, and the method is suitable for large-scale preparation.
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Paragraph 0031-0035
(2020/05/30)
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- N,N'-disubstituted urea compound and synthesis method thereof
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The invention discloses an N,N'-disubstituted urea compound and a preparation method thereof. N-alkyl acyloxy amide is taken as a raw material and a dichloro(p-cymene)ruthenium(II) dimer complex is taken as a catalyst for carrying out a reaction in an organic solvent under the presence of silver acetate, and the N,N'-disubstituted urea compound is prepared. Compared with the prior art, the methodhas the following advantages that only an amide derivative is taken as a raw material, reaction conditions are mild, the application range of substrates is wide, operation is simple and convenient, the catalyst is low in price, and selectivity of the product is high.
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Paragraph 0067-0070
(2019/04/10)
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- A simple and efficient synthesis of diaryl ureas with reduction of the intermediate isocyanate by triethylamine
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Thirty symmetrical diaryl urea derivatives were synthesised in moderate to excellent yields from arylamine and triphosgene with triethylamine as a reducing agent for the intermediate, isocyanate. It was significant that part of the products could be collected in almost quantitative yield without column chromatography. The procedure under mild reaction conditions was tolerant of a wide range of functional groups. The structures of the compounds were determined by NMR, MS and X-ray crystallographic analyses.
- Zhou, Shuguang,Yao, Ting,Yi, Jicheng,Li, Dashuai,Xiong, Jing
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p. 315 - 319
(2013/07/27)
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- Synthesis of unsymmetrical 2-pyridyl ureas via selenium-catalyzed oxidative carbonylation of 2-aminopyridine with aromatic amines
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A simple, one-pot, phosgene-free approach to a series of unsymmetrical 2-pyridyl ureas starting from 2-aminopyridine and various aromatic amines is reported for the first time. The procedure employs inexpensive selenium as the catalyst, and carbon monoxide (instead of phosgene) as the carbonyl reagent. The products are obtained in moderate to good yields via selenium-catalyzed oxidative cross-carbonylation of the substrate amines in the presence of oxygen. The selenium functions as a phase-transfer catalyst and can be recovered easily and reused without any significant degradation of its catalytic activity.
- Zhang, Xiaopeng,Li, Desheng,Ma, Xueji,Wang, Yan,Zhang, Guisheng
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p. 1357 - 1363
(2013/07/05)
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- Palladium-catalyzed carbonylation of amines: Switchable approaches to carbamates and N,N′-disubstituted ureas
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Switchable access to carbamates and ureas has been developed by solvent control palladium-catalyzed carbonylation of aromatic amines under an atmosphere of carbon monoxide. A variety of N-phenylcarbamates and N,N′- diphenylureas was easily synthesized in good to excellent yields from readily available aromatic amines under mild conditions. Copyright
- Guan, Zheng-Hui,Lei, Hao,Chen, Ming,Ren, Zhi-Hui,Bai, Yinjuan,Wang, Yao-Yu
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supporting information; experimental part
p. 489 - 496
(2012/04/04)
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- Microwave induced improved synthesis of monoaryl thiocarbamides, 1,3-diarylthiocarbamides, 1,3-diarylcarbamides and monoaryl-2,4-dithiobiurets
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The 1-arylthiocarbamides (3), 1, 3-diarylthiocarbamides (6), 1,3-diarylcarbamides (7) and 1-aryl-2,4-dithiobiurets (11) have been synthesized by the microwave induced heating of respective reactants for about 30-60 s in solvent free condition. Reaction yields are higher with reduced time, period and without the use of any solvent.
- Uberhande,Thakare,Berad
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experimental part
p. 1137 - 1141
(2011/05/05)
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- One-pot synthesis of symmetrical 1,3-diarylureas or substituted benzamides directly from benzylic primary alcohols and effective oxidation of secondary alcohols to ketones using phenyliodine diacetate in combination with sodium azide
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Benzylic primary alcohols can be directly converted into symmetrical 1,3-diarylureas or substituted benzamides via an one-pot oxidative reaction using the combined reagent of phenyliodine diacetate and sodium azide. This new reaction constitutes a step-economical way to prepare symmetric 1,3-diarylureas or substituted benzamides depending upon the substituents on the phenyl rings of starting alcohols. The sodium acetate generated in situ from the ligand exchange between phenyliodine diacetate and sodium azide plays the pivotal role in the formation of 1,3-diarylureas. In addition, it is also found that various secondary alcohols can be readily oxidized to their corresponding ketones in excellent yields using the same reagent system of phenyliodine diacetate and sodium azide. Generally, secondary alcohols are preferentially oxidized to the corresponding ketones in the presence of primary ones with the limited amounts of phenyliodine diacetate and sodium azide.
- Li, Xiao-Qiang,Wang, Wei-Kun,Han, Yi-Xin,Zhang, Chi
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experimental part
p. 2588 - 2598
(2010/12/25)
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- Synthesis of symmetrical ureas by (Diacetoxyiodo)benzene-induced hofmann rearrangement
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Amides undergo Hofmann rearrangement by treatment with (diacetoxyiodo) benzene (DAIB) to provide symmetrical ureas in a simple and robust transformation. Georg Thieme Verlag Stuttgart - New York.
- Landsberg, Dirk,Kalesse, Markus
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experimental part
p. 1104 - 1106
(2010/06/19)
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- Synthesis and activity of 1,3,5-triphenylimidazolidine-2,4-diones and 1,3,5-triphenyl-2-thioxoimidazolidin-4-ones: Characterization of new CB 1 cannabinoid receptor inverse agonists/antagonists
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Obesity and metabolic syndrome, along with drug dependence (nicotine, alcohol, opiates), are two of the major therapeutic applications for CB 1 cannabinoid receptor antagonists and inverse agonists. In the present study, we report the synthesis and structure-affinity relationships of 1,5-diphenylimidazolidine-2,4-dione and 1,3,5-triphenylimidazolidine-2,4-dione derivatives. These new 1,3,5-triphenylimidazolidine-2,4-dione derivatives and their thio isosteres were obtained by an original pathway and exhibited interesting affinity and selectivity for the human CB1 cannabinoid receptor. A [35S]-GTPγS binding assay revealed the inverse agonist properties of the compounds at the CB1 cannabinoid receptor. Furthermore, molecular modeling studies were conducted in order to delineate the binding mode of this series of derivatives into the CB1 cannabinoid receptor. 1,3-Bis(4-bromophenyl)-5-phenylimidazolidine-2,4-dione (25) and 1,3-bis(4-chlorophenyl)-5-phenylimidazolidine-2,4-dione (23) are the imidazolidine-2,4-dione derivatives possessing the highest affinity for the human CB1 cannabinoid receptor reported to date.
- Muccioli, Giulio G.,Wouters, Johan,Charlier, Caroline,Scriba, Gerhard K. E.,Pizza, Teresa,Di Pace, Pierluigi,De Martino, Paolo,Poppitz, Wolfgang,Poupaert, Jacques H.,Lambert, Didier M.
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p. 872 - 882
(2007/10/03)
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- Expeditious method for synthesis of symmetrical 1,3-disubstituted ureas and thioureas
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Symmetrical 1,3-disubstituted ureas and symmetrical thioureas have been synthesized from corresponding isocyanates, diisocyanates, and isothiocyanates by a new versatile, simple, and quick method in the presence of tertiary amines at room temperature. The method under discussion has several advantages over the existing techniques, as it is simple to carry out, does not require complicated equipment, has a simple workup, and does not use expensive chemicals. Moreover, the yields are almost quantitative. This method has potential in commercial applications. Copyright Taylor & Francis, Inc.
- Perveen, Shahnaz,Abdul Hai, Syed M.,Khan, Rashid A.,Khan, Khalid Mohammed,Afza, Nighat,Sarfaraz, Tahira B.
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p. 1663 - 1674
(2007/10/03)
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- Recyclization of 2,6-diamino-4-aryl(cyclohexyl)-3,5-dicyano-4H-thio(seleno) pyrans
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Recyclization of 2,6-diamino-4-aryl(cyclohexyl)-3,5-dicyano-4H-thio(seleno) pyrans in the presence of an equimolar amount of an α-bromo carbonyl compound, ethyl iodide, 1,2-dibromoethane, or 3-chlorophenyl isocyanate yields, respectively, 3-aryl(cyclohexy
- Dyachenko,Chernega,Garasevich
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p. 1610 - 1617
(2007/10/03)
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- Selenium-catalyzed reductive carbonylation of nitrobenzene with amines as coreagents to give unsymmetric phenylureas
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The reductive carbonylation of nitrobenzene catalyzed by selenium to yield unsymmetric phenylureas has been studied. When secondary amines were used as coreagents, a single product, PhNHCONR2, was formed; when primary amines were chosen as coreagents, mixed products, including RNHCONHR, RNHCONHPh and PhNHCONHPh, were obtained.
- Yang, Ying,Lu, Shiwei
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p. 4845 - 4846
(2007/10/03)
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- NEW ROUTE FOR THE SYNTHESIS OF SYMMETRICAL DIARYLUREA
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Several esters of aryl carbamic acid were thermally dissociated into symmetrically diarylurea in high yields.The electronic effect and position of the substitution in the aryl groups as well as the role of the alkyl groups on the thermal reaction are discussed.
- Hassan, Alaa A.,Mourad, Aboul-Fetouh E.
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p. 397 - 404
(2007/10/02)
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- Preparation of Benzo-diimidazoles and Benzo-triimidazoles
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The reaction of benzenehexamine (1), benzene-1,2,3,4-tetramine (4), and benzene-1,2,4,5-tetramine (6) with aryl isocyanate 2 afforded the corresponding hexakis(N'-arylureido)benzene 3 and the tetrakis(N'-arylureido)benzenes 5 and 7.Pyrolysis of 3, 5, and 7 at 400 deg C furnished the benzo-triimidazoletrione 8 and benzo-biimidazolediones 10 and 11. - Key Words: Benzo-triimidazoles / Benzo-diimidazoles / Benzenehexamine
- Mataka, Shuntaro,Irie, Takashi,Ikezaki, Youji,Tashiro, Masashi
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p. 1819 - 1822
(2007/10/02)
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- A new route for the synthesis of symmetrical diarylureas
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Several esters of arylcarbamic acid have been thermally dissociated into symmetrical diarylureas in high yields.The electronic effect and position of substitution in the aryl groups as well as the role of alkyl groups on thermal reaction have been discussed.
- Hassan, Alaa A,Mourad, Aboul-fetouh E
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p. 277 - 279
(2007/10/02)
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- Nucleophilic Substitutions at Carbonic Acid Derivatives. XX. Aminolysis of Bis(trichlormethyl)carbonate
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The rate constants for the two steps of the reaction of bis(trichlormethyl)carbonate with substituted anilines have been determinated by conductivity measurements.The first relatively fast step of the reaction is the nucleophilic attack of the amine to the bis(trichloromethyl)carbonate leading to trichloromethylurethane through a six or four centers transition state in wich the carbon-nitrogen bond is formed parallel with the transfer of the proton.In this reaction a phosgene molecule is also produced, which reacts very fast with amine to form a N,N'-diarylurea.The s econd, much slower step, is the nucleophilic attack of the amine to the trichloromethylurethane.Through a similar transition state in which the proton transfer has even a higher importance, a N,N'-disubstituted urea and an other molecule of phosgene are formed.
- Cotarca, Livius,Bacaloglu, R.,Csunderlik, C.,Marcu, N.,Tarnaveanu, A.
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p. 1052 - 1062
(2007/10/02)
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- Muscarinic Ganglionic Stimulants: Conformationally Restrained Analogues Related to oxy>-2-butynyl>trimethylammonium Chloride
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The synthesis of a series of tertiary and quaternary cyclic analogues (isoarecolinol, dihydroisoarecolinol, arecolinol and 3-pyrroline-3-carbinol derivatives) of oxy>-2-butynyl>trimethylammonium chloride (McN-A-343) (1), a
- Lambrecht, Guenter,Moser, Ulrich,Mutschler, Ernst,Walther, Gerhard,Wess, Juergen
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p. 1309 - 1311
(2007/10/02)
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- SUBSTITUENT EFFECTS ON HYDROLYTIC STABILITY AND HERBICIDAL ACTIVITY OF 3-ARYLIMIDAZOLIDINE-2,4-DIONES
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Twenty-one derivatives of imidazolidine-2,4-dione have been prepared by reactions of substituted amino acids with aryl isocyanates in aqueous medium.Pre- and post-emergent herbicidal activities of all the compounds have been tested, and stability of five derivatives has been followed in aqueous medium within the pH range from 7.6 to 13.0.The highest pre-emergent herbicidal activity has been found with the derivatives XI-XVI which inhibit the growth of most indicator plants at the doses of 1.6 kg/ha.The derivatives studied are relatively stable in aqueous medium, the hydrolysis half-life of the compound XI being 9 days at pH 8.
- Cegan, Alexandr,Vecera, Miroslav
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p. 1521 - 1528
(2007/10/02)
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- Investigations of the Products of Isocyanates with Hydroxylamine
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The reactions of isocyanates with hydroxylamine give rise to several compounds according to the different conditions involved when starting with the primary reaction products, the hydroxy-ureas.The pure compounds have been isolated.An interesting reaction of N-phenyl-N'-phenylcarbamoyloxyurea with sodium hydroxide has been observed.This compound is converted to 3-hydroxy-1,5-diphenylbiuret under conditions described.
- Becker, Alfred,Heizler, Werner
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p. 1011 - 1017
(2007/10/02)
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- 3-(1-Hydroxyalkyl)-1,4,2-dioxazol-5-ones and 3-Hydroxyoxazolidine-2,4-diones from 2-Hydroxycarbohydroxamic Acids and 1,1'-Carbonyldiimidazole
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The reaction of 2-hydroxycarbohydroxamic acids 6 with 1,1'-carbonyldiimidazole produces 3-(1-hydroxyalkyl)-1,4,2-dioxazol-5-ones 7 and 3-hydroxyoxazolidine-2,4-diones 8.The formation of the heterocycles 7 and 8 depends largely on the substitution at C-2 of 6.Excess of imidazole causes rapid decomposition of 7 into carbonyl compound 9 and isocyanic acid, which yields the adduct 10 with imidazole.Benzylaminolysis of 7a gives 11 whereas the reaction of 7a with 3-chloroaniline produces the ureas 12 and 14 and benzophenone (9a).From the reaction of 7a with imidazole in a mole ratio of 1 : 1 the decomposition products 9a and 10 and 3-hydroxy-5,5-diphenyloxazolidine-2,4-dione (8a) are obtained.
- Geffken, Detlef
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p. 211 - 218
(2007/10/02)
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- Orthoamides, XXXVIII. - Contributions to the Chemistry of Orthocarbonic Acid Esters and α,α,α-Trialkoxyacetonitriles
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The reactivity of the orthocarbonates 4 and the nitriles 1 has been investigated.Carboxylic acids are esterified by 4b. Orthocarbonates 4c-f and 9b are prepared by transesterification of 4b.Mixed substituted orthocarbonates 8c-f are obtained from the nitriles 1a,b.The nitriles 2a and 3a react with alkali alcoholate in alcohol to yield the orthocarbamic acid esters 13a,b. Spirocyclic orthocarbonates 17a-d are prepared from 4b and 1,2 or 1,3-dioles, respectively. The reaction of phenol with 1b affords the mixed substituted orthocarbonate 18a. Catechol is converted by 1a into the orthocarbonate 20a.Reactions of 4b with amines and ami ne derivatives are studied. In the course of these investigations guanidines 21, imidocarbonic acid esters 22a-c, 30, carbamic acid esters 25, ureas 26, the isourea derivative 29, as well as the 1,3,4-oxadiazole 31 are prepared. The mechanism of these reactions is discussed. Imidocarbonic acid esters 22d-f, 38, N-cyanocarbamates 39, and isoureas 37 can be prepared from 1b and amines or amine derivatives. 2a as well as 13b react with cyanamide to give the N-cyanoisourea 40. Ureas 26 are formed in the reaction of 1a,b with secondary amines at elevated temperatures.The guanidinium cyanide 41a can be obtained by reaction of pyrrolidine with 1b in ether, whereas under similiar conditions from 1a and pyrrolidine the amidine 42 is produced. o-Aminophenol, o-phenylenediamine and anthranilic acid are cyclized by 4b or 1b to afford the heterocyclic compounds 43-45. α- and β-amino acids are transformed by 4b or 1b into the N-(ethoxycarbonyl)amino acid esters 46 and 47, respectively.
- Kantlehner, Willi,Maier, Thomas,Loeffler, Wolfgang,Kapassakalidis, Joanis J.
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p. 507 - 529
(2007/10/02)
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