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1.
[reaction: see text] A fluorous synthesis of hydantoins is introduced. The reaction of perfluoroalkyl (Rfh)-tagged amino esters with an isocyanate is followed by the cyclization of ureas and simultaneous cleavage of the fluorous tag to afford hydantoins. The product purification is performed by solid-phase extraction over FluoroFlash cartridges, and no fluorous solvent is involved in either the reaction or the separation processes. The same method applies to synthesis of thiohydantoins. 相似文献
2.
Graziano Baccolini Carla BogaCamilla Delpivo Gabriele Micheletti 《Tetrahedron letters》2011,52(14):1713-1717
A series of hydantoins and thiohydantoins have been synthesized in water at room temperature from urea (or N-methylurea, or thiourea) and simple aldehydes (as glyoxal, and its simple derivatives) in the presence of phosphoric anhydride. The reaction time is 10 min using an equimolar amount of P4O10 with respect to the other reagents, but the reaction occurs also, even if with longer reaction times, with very small amounts of P4O10.In addition, this method provides a clean and ‘green’ approach to hydantoins, compounds of great interest in biological and pharmacological fields. 相似文献
3.
Nefzi A Giulianotti M Truong L Rattan S Ostresh JM Houghten RA 《Journal of combinatorial chemistry》2002,4(2):175-178
An efficient method for the solid-phase synthesis of hydantoins and thiohydantoins tethered to ureas, starting from a resin-bound amino acid, is presented. Following reduction of the amide with borane-THF, a second amino acid was selectively coupled to the primary amine followed by treatment of the secondary amine by an isocyanate to generate the corresponding urea. Hydantoin and thiohydantoin formation was achieved through the use of carbonyldiimidazole and thiocarbonyldiimidazole, respectively. Cleavage from the solid support using hydrogen fluoride, followed by extraction and lyophilization, provided the desired urea-linked heterocyclic compounds in good yield and high purity. 相似文献
4.
Substituted 5-aryl-3-ethylidene-3H-pyrrol-2-ones were synthesized by the reaction of the corresponding 4-aryl-4-oxobutanoic acids with ketones in the presence
of aminating agents. The conditions of this reaction were developed with the use of both the conventional condensation technique
and microwave activation. The structures of the reaction products were con-firmed by elemental analysis, IR spectroscopy,
and 1H NMR spectroscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 693–696, April, 2006. 相似文献
5.
R. L. Antipin E. K. Beloglazkina A. G. Magouga A. N. Chernysheva N. V. Zyk 《Chemistry of Heterocyclic Compounds》2008,44(9):1135-1137
It has been shown that bromination of 5-aryl-5-benzylidene-3,5-dihydro-4H-2-methylthioimidazol-4-one in methylene chloride
at room temperature leads to the addition of bromine at the double bond, but the the reaction of 5-aryl-3,5-dihydro-4H-2-methylthio-5-(2-pyridylmethylene)imidazol-4-one
gave complex compound of the starting materials. After boiling both of the compounds obtained in ethanol the corresponding
5-[bromo(aryl)methylene]imidazolidine-2,4-diones were obtained.
Dedicated to Academician B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1406–1408, September, 2008. 相似文献
6.
A convenient and efficient procedure for the synthesis of quinolines and dihydroquinolines has been developed by a simple one-pot reaction of anilines with alkyl vinyl ketones on the surface of silica gel impregnated with indium(III) chloride under microwave irradiation without any solvent. 相似文献
7.
Khalil Faghihi Khosrow Zamani Azizollah Mirsamie Mohammad Reza Sangi 《European Polymer Journal》2003,39(2):247-254
Rapid and highly efficient synthesis of novel optically active poly(amide-imide)s (PAIs) 6(a-f) was achieved using microwave irradiation. These were made from the polycondensation reactions of 4,4′-carbonyl-bis(phthaloyl-l-alanine) diacid chloride [N,N′-(4,4′-carbonyldiphthaloyl)] bisalanine diacid chloride 5 with six different derivatives of hydantoin and thiohydantoin compounds 4(a-f) in the presence of a small amount of a nonpolar organic medium that acts as a primary microwave absorber. Hydantoin and thiohydantoin derivatives 4(a-e) were synthesis from the reactions between benzil or benzil derivatives 3(a-e) with urea and thiourea. 5,5-Dimethylhydantoin 4f was synthesis from the reactions between acetone cyanohydrin 3f and ammonium carbonate. The polycondensation proceeded rapidly, and was completed within 10 min giving a series of PAIs with an inherent viscosity about 0.25-0.45 dL/g. The resulting PAIs 6(a-f) were obtained in a high yield and were optically active and thermally stable. All of the above compounds were fully characterized by means of Fourier transform infrared spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility tests and specific rotation. Thermal properties of the PAIs 6(a-f) were investigated using thermal gravimetric analysis. 相似文献
8.
Federico MeddaChristopher Hulme 《Tetrahedron letters》2012,53(42):5593-5596
This Letter describes novel methodology for the rapid assembly of new and biologically appealing 1,5-substituted tetrazole-hydantoins and thiohydantoins. The product of a TMSN3-Ugi multi-component reaction is treated with an excess of isocyanate or isothiocyanate to generate the final scaffold in moderate to good yields. The applicability of this solution phase methodology to the preparation of a small collection of compounds is discussed. 相似文献
9.
An efficient synthesis of cinchona alkaloid-derived ligands based on solvent-free microwave-assisted reaction was described. The coupling of 1,4-dichlorophthalazine or 3,6-dichloropyridazine with quinine, cinchonine or cinchonidine provide bis-or monocinchona alkaloid-derived ligands in moderate to good yields (52-89%) within 15 min under optimum microwave conditions. 相似文献
10.
B. Sreedhar P. Surendra Reddy B. Veda Prakash A. Ravindra 《Tetrahedron letters》2005,46(41):7019-7022
Ultrasound was used for the addition of metal acetylides to in situ generated imines to generate propargylamines in good to excellent yields using copper iodide in water at ambient temperature. This process is an efficient alternative to traditional heated reactions. A variety of aldehydes and amines were used for this reaction. 相似文献
11.
12.
Microwave-assisted modified Sandmeyer reactions of oximinoacetanilides, themselves obtained from substituted primary aromatic amines, in concentrated H2SO4 give isatins. N-Acetylisatins undergo ring cleavage and subsequent ring closing with alkanediamines in the presence of ethanol under MW irradiation to give the corresponding dihydropyrazinones in excellent yields. Modification of the reaction conditions affords bis-benzoylketones under MW irradiation. 相似文献
13.
14.
Hirokazu Iida Yusuke Akatsu Kazushi Mizukami Sho Natori Minako Matsukawa Kie Takahashi 《合成通讯》2016,46(7):581-585
The addition of phenols to acrylonitrile in the presence of aqueous benzyltrimethylammonium hydroxide or tetramethylammonium hydroxide under microwave irradiation yielded the corresponding Michael adducts. The obtained adducts were easily transformed to phenolic analogs of 4-phenylbutanoic acids via the hydrolysis of nitrile groups. 相似文献
15.
Microwave activation coupled with Cu(I) catalysis, under solvent-free conditions, was found to dramatically enhance the 1,3-dipolar cycloaddition between azido-2′-deoxyribose and terminal alkynes. The process is highly efficient and quantitatively affords, in few minutes, the corresponding 4-substituted 1,2,3-triazolyl-nucleosides. 相似文献
16.
Richard S. PottorfNaresh K. Chadha Martins KatkevicsVita Ozola Edgars SunaHadi Ghane Tor RegbergMark R. Player 《Tetrahedron letters》2003,44(1):175-178
A facile route to benzoxazoles has been developed using microwave-assisted dielectric heating. The ease of synthesis and workup allowed the parallel synthesis of a 48-membered library of benzoxazoles quickly and efficiently. 相似文献
17.
Mehdi Adib Mohammad Mahdavi Farzad Malihi Hamid Reza Bijanzadeh 《Tetrahedron letters》2009,50(52):7246-3194
A novel synthesis of 5-(alkylamino)-4-aryl-3-isoxazolecarboxamides is described. Heating a mixture of an isocyanide and a nitrostyrene in water afforded the title compounds in excellent yields. 相似文献
18.
Ganesh C. Nandi 《合成通讯》2017,47(4):319-323
An efficient and microwave-assisted simple protocol for the synthesis of symmetrical/asymmetrical diaryl sulfones through the Cu(II)-catalyzed reaction of sodium salt of sulfinic acid with aryl boronic acid has been described. Various diaryl sulfones have been synthesized in very short reaction times with moderate to very good yields. Additionally, the method is also useful for the synthesis of aryl vinyl sulfones. 相似文献
19.
The Michael condensation in the series of 5-aryl-3-arylidene-3H-pyrrol-2-ones and 5-aryl-3-arylidene-3H-furan-2-ones, containing
an activated C=C bond, with cyclohexanone was investigated. It was shown that the condensation products were 1,5-dicarbonyl
compounds containing a heterocyclic fragment. The enolization of one of the oxo groups, leading to the formation of hydroxypyrrole
or hydroxyfuran structures, was demonstrated by the spectral data.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 823–827, June, 2007. 相似文献
20.
《Green Chemistry Letters and Reviews》2013,6(1):63-68
Abstract One-pot synthesis of indolyl chalcones (3a–c) employing indole-3-carboxaldehyde (1) and heteroaryl active methyl compounds (2a–c) under microwave irradiation is described. The indolyl chalcones (3a–c) are transformed into medicinally important pyrazolines (5a–f) using different hydrazines. Application of microwave irradiation leads to many remarkable advantages, such as solvent- and catalyst-free reaction conditions, simple work up procedure, shorter reaction time, in addition to ecofriendly ‘green chemistry’ economical and environmental impacts. 相似文献