96-31-1Relevant articles and documents
Preparation and reaction of uracil substituted cyclen and cyclam: formation of tricyclic guanidinium and dihydroimidazolium salts
Watanabe, Soichiro,Komori, Ayako,Saito, Masayuki,Uchida, Akira
, p. 1196 - 1201 (2010)
Di-uracil substituted cyclen derivatives were prepared by the reaction of cyclen with 6-chloro-1-methyluracil or 6-chloro-1,3-dimethyluracil. The reaction of cyclam with 6-chloro-1,3-dimethyluracil gave a similar di-uracil substituted cyclam. The 1,7-di-uracil substituted cyclen was converted to the tricyclic guanidinium salt and acylurea upon heating in DMSO in the presence of weak acid. The 1,8-di-uracil substituted cyclam gave a tricyclic dihydroimidazolium salt under the same conditions. These reactions can be explained by an intramolecular uracil ring-breaking reaction mechanism.
Reactions of 2-amino-2-thiazolines with isocyanates and isothiocyanates. Chemical and computational studies on the regioselectivity, adduct rearrangement, and mechanistic pathways
Avalos,Babiano,Cintas,Chavero,Higes,Jimenez,Palacios,Silvero
, p. 8882 - 8892 (2000)
2-Amino-2-thiazoline derivatives bearing alkyl or aryl substituents at exocyclic nitrogen have been condensed with different isocyanates and isothiocyanates. The addition occurs at ring endocyclic nitrogen in a regiospecific manner to afford kinetic and enthalpy-favored adducts. The unequivocal assignment of these structures has been confirmed by X-ray diffraction analyses of several compounds. The endo adducts do not rearrange on heating with the sole exception of adducts in which the exocyclic nitrogen remains unsubstituted. Trapping experiments in the presence of other isocyanates or isothiocyanates produce the formation of new endo adducts by acyl exchange in the reaction mixture. Semiempirical PM3 calculations full corroborate the higher stability of endo or exo adducts depending on the substitution pattern. The formation of adducts is compatible with a stepwise reaction mechanism, for which semiempirical transition structures could be located in the potential energy surface, and the global energetics of the process have been determined. The formation of the endo adducts proceeds with a smaller activation barrier.
On the Reaction of Acylium Salts with Isocyanates
Hamed, A.,Ismail, A.,Hitzler, M. G.,Jochims, J. C.
, p. 385 - 390 (1995)
Alkyl isocyanates (3) react with acylium salts (2) in a 2:1 ratio to furnish 3,4-dihydro-2,4-dioxo-2H-1,3,5-oxadiazinium salts 4.These cyclic N-acyliminium salts are decomposed with catalytic amounts of water to give either oxadiazinium salts 5 or pyrimidinium salts 7.With aqueous base compounds 4 are transformed into acylureas 6.Hetero substituted open chain N-acyliminium slats (8a, 11c, 12c, 13f, 15g, 16a) are produced from 4 by treatment with heteronucleophiles such as methanol, p-anisidine, p-cresol, thiophenol, 1,3-dimethylurea, or benzohydrazide, respectively.Excess of nucleophile furnishes further degradation products of 4, e.g. oxonium salts (9a) and iminium salts (14f).
Regioselective Formal [3+2] Cycloadditions of Urea Substrates with Activated and Unactivated Olefins for Intermolecular Olefin Aminooxygenation
Wu, Fan,Alom, Nur-E,Ariyarathna, Jeewani P.,Na?, Johannes,Li, Wei
supporting information, p. 11676 - 11680 (2019/07/31)
A new class of intermolecular olefin aminooxygenation reaction is described. This reaction utilizes the classic halonium intermediate as a regio- and stereochemical template to accomplish the selective oxyamination of both activated and unactivated alkenes. Notably, urea chemical feedstock can be directly introduced as the N and O source and a simple iodide salt can be utilized as the catalyst. This formal [3+2] cycloaddition process provides a highly modular entry to a range of useful heterocyclic products with excellent selectivity and functional-group tolerance.
Cyclization Reaction of Donor-Acceptor Oxiranes with N,N′-Disubstituted Thioureas: A Domino Process to trans-Dihydropyrimidines
Wang, Jing,Zhang, Qi-Ying,Xie, Ming-Sheng,Wang, Dong-Chao,Qu, Gui-Rong,Guo, Hai-Ming
supporting information, p. 6578 - 6582 (2018/10/20)
An unprecedented cyclization reaction of donor-acceptor oxiranes with N,N′-disubstituted thioureas to construct trans-dihydropyrimidines is presented. Preliminary reaction mechanism studies demonstrated that the reaction underwent sequential cycloaddition/amine ester exchange/oxygen-sulfur exchange/desulfuration/Michael addition process. A wide range of trans-dihydropyrimidines were produced with high yields up to 94% by using this method.
Synthesis and architecture of polystyrene-supported Schiff base-palladium complex: Catalytic features and functions in diaryl urea preparation in conjunction with Suzuki-Miyaura cross-coupling reaction by reductive carbonylation
Basu, Priyanka,Riyajuddin, Sk,Dey, Tusar Kanto,Ghosh, Aniruddha,Ghosh, Kaushik,Islam, Sk Manirul
, p. 37 - 50 (2018/10/02)
This work represents an efficient and unique phosphine-free approach for the polystyrene embedded Schiff-base palladium catalyzed diaryl urea synthesis and Suzuki-Miyaura cross-coupling reaction by reductive carbonylation process. The careful instrumental investigations with FE-SEM, TEM, EDAX, TGA, UV–Vis, FTIR, AAS, and elemental analysis precisely characterized the developed heterogeneous catalyst. Reaction parameters, like catalytic natures, starting materials, reaction environment, and solvent were examined sequentially. The present work has been adequately addressed to account for the generation and characterization of a new polymer bound Pd-catalyst and using it in the synthesis of diaryl ureas and diaryl ketones, with no substantial decay of catalytic activity.
Chloromethylated polystyrene immobilized ruthenium complex of 2-(2-pyridyl)benzimidazole catalyst for the synthesis of bioactive disubstituted ureas by carbonylation reaction
Dey, Tusar Kanto,Ghosh, Kajari,Basu, Priyanka,Molla, Rostam Ali,Islam, Sk. Manirul
, p. 9168 - 9176 (2018/06/08)
Polymer supported transition metal complex catalysts have numerous applications as heterogeneous catalysts due to their ease of synthesis and commercial availability. Ru-Py-Merf was synthesized by anchoring 2-(2-pyridyl)benzimidazole to the polymer matrix, followed by loading of ruthenium salt. This Ru-Py-Merf material was thoroughly characterized by FTIR spectroscopy, UV-vis absorption spectroscopy, FE-SEM analysis, EDAX analysis, CHN analysis, AAS spectroscopy and TGA. Ru-Py-Merf showed excellent catalytic activity in the synthesis of symmetric and asymmetric disubstituted ureas by reductive carbonylation of nitrobenzenes and anilines. The as-synthesized Ru-Py-Merf catalyst is entirely heterogeneous in nature, thermally stable and can be easily reused up to six times.
METHOD FOR ALKYLATING AN AMINO COMPOUND
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Page/Page column 14; 15, (2018/06/12)
The invention relates to a method for alkylating an amino compound, characterized in that at least one triazine derivative of general formula (I) or at least one urea or urea derivative of the general formula (II), (II), wherein ? R4 and R5 mean independently from each other Q1 or a moiety of the formula R6-N-R7 or R8-N-R9 bound with its central nitrogen atom to the triazine ring of the structure of formula (I), whereat - Q1 means a linear or branched C1-C30-alkyl or a cyclic substituent in form of a C5-C20-cycloalkyl, a C5-C20-aryl, a C1-C20-alkylsubstituted C5-C20-aryl or an amide of a cyclic unsaturated carboxylic acid, whereat the C1-C30-alkyl or the cyclic substituent can be interrupted by one or multiple oxygen atoms, sulphur atoms, substituted nitrogen atoms and/or by one or multiple groups of the type –C(O)O-,-OC(O)-,-C(O)- and/or –OC(O)O-, ? R1, R2, R3, R6, R7, R8 and R9 mean independently from each other H, linear or branched C1-C20-alkyl, C5-C20-cyclo alkyl, C5-C20-aryl, C1-C20-alkylsubstituted C5-C20-aryl, which in each case can be interrupted by one or multiple oxygen atoms, sulphur atoms and/or substituted nitrogen atoms and/or by one or multiple groups of the type –C(O)O-, - OC(O)-, -C(O)- and/or –OC(O) O- and/or can be functionalized by one or multiple hydroxyl groups and/or mercapto groups, and ? X means O or S, is reacted with at least one alcohol of the general formula (III) R10-OH wherein R10 means a linear or branched C1-C20-alkyl, C5-C20-cycloalkyl, or C1-C20- alkylsubstituted C5-C20-aryl, which can be in each case interrupted by one or multiple oxygen atoms, sulphur atoms, substituted nitrogen atoms and/or by one or multiple groups of the type –C(O)O-, -OC(O)-, -C(O)- and/or –OC(O)O- and/or can be functionalized by one or multiple hydroxyl groups and/or mercapto groups, wherein the reaction is carried out in the presence of at least one Ruthenate of the general formula (IV) Mn(RuO4) and/or at least one Perruthenate of the general formula (V) M(RuO4)n wherein the cation M is selected from a group comprising an alkali, earth alkali or substituted or non-substituted ammonium cation.
Direct Conversion of Haloarenes to Phenols under Mild, Transition-Metal-Free Conditions
Fier, Patrick S.,Maloney, Kevin M.
supporting information, p. 2244 - 2247 (2016/06/01)
A high-yielding and practical method for the synthesis of phenols from electron-deficient haloarenes and heteroarenes has been developed. The products are formed from acetohydroxamic acid as the hydroxide source via a novel SNAr reaction/Lossen rearrangement sequence. Notably, these reactions employ inexpensive and air-stable reagents, require no special handling, occur under mildly basic conditions, and form products in high yields in the presence of electrophilic and protic functionality. The utility of this methodology is demonstrated by the high-yielding hydroxylation of two base-sensitive complex substrates.
Direct extraction of carbonyl from waste polycarbonate with amines under environmentally friendly conditions: Scope of waste polycarbonate as a carbonylating agent in organic synthesis
Singh, Sukhdeep,Lei, Yong,Schober, Andreas
, p. 3454 - 3460 (2015/02/19)
An efficient green method for converting waste polycarbonate into urea derivatives by reacting with primary amines has been developed. Simple treatment of polycarbonate plastic with primary amines in a closed vial at 80 °C without using any catalyst and toxic solvents made this process environmentally friendly. Digestion of the waste polycarbonate obtained from CDs and DVDs with amines affords functionalized urea and 4,4′-(propane-2,2-diyl)diphenol (BPA, bisphenol-A). The procedure is optimized to get maximum conversion of polymer to urea and its derivatives as a major product. The purification procedure to isolate the urea derivatives in the presence of bisphenol-A has been tuned to avoid chromatographic procedures. This environmentally friendly method provides (i) an alternative for recycling BPA from polycarbonate, (ii) a method of obtaining useful product like urea derivatives, (iii) scope for new carbonylating agents in organic synthesis, (iv) an amine functionalized polycarbonate surface. This journal is
