Uncatalyzed addition of indoles and N-methylpyrrole to 3-formylchromones: synthesis of (chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones under solvent-free conditions

(Chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones have been obtained in good yields from 3-formylchromones on reaction with indoles and N-methylpyrrole under solvent-free conditions.     

Aroyl[bis(4-hydroxycoumarin-3-yl)]methanes in reactions with 1,2-diaminobenzenes

The reaction of aroyl[bis(4-hydroxycoumarin-3-yl)]methanes with 1,2-phenylenediamines in PrⁱOH is accompanied by the recyclization to 8-R-or 7-R-4-(2-hydroxyphenyl)-1,5-benzodiazepin-2-ones, whereas the reaction with o-phenylenediamine and its 4-methyl-substituted derivatives in MeOH produces organic ionic salts of the bis-coumarin anion with monoprotonated o-phenylenediamine as the cation. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2200–2205, November, 2007.     

蒙脱土K10-ZnCl2催化下研磨法合成二吲哚甲烷衍生物

蒙脱土K10固载_^ZnCl2是一个有效的环境友好催化剂. 在蒙脱土K10-ZnCl2催化下, 将吲哚与芳香醛混合在研钵中研磨2～8 min, 可得到收率为66%～97%的二吲哚甲烷衍生物. 该方法具有操作简便、反应条件温和、反应时间缩短、 对环境友好等优点.     

An efficient synthesis of 3-(indol-3-yl)quinoxalin-2-ones with TfOH-catalyzed Friedel-Crafts type coupling reaction in air

An efficient one-pot synthetic approach to access a variety of 3-(indol-3-yl)quinoxalin-2-ones from various quinoxalin-2-ones and very wide scope of indoles through TfOH-catalyzed Friedel-Crafts type coupling reaction in DMF has been developed. Only 10 mol % Brønsted acid as a catalyst, air as an oxidizer, and very wide range of substrates are the prominent advantages of this method.     

Rapid and Efficient Synthesis of 3,3-Di(1H-indol-3-yl)indolin-2-ones and 2,2-Di(1H-indol-3-yl)-2H-acenaphthen-1-ones Catalyzed by p-TSA

An efficient synthesis of 3,3-di(1H-indol-3-yl)indolin-2-ones and 2,2-di(1H-indol-3-yl)-2H-acenaphthen-1-ones via a reaction of various isatins or acenaphthenequinone with indoles in the presence of p-methylbenzene sulfonic acid (p-TSA) in CH₂Cl₂ at room temperature is described. The advantages of this method include good reaction yield, simple workup procedure, and mild reaction condition.     

Eu(NTf2)3催化吲哚与醛(酮)反应合成二吲哚基甲烷

二(三氟甲基磺酰)亚胺铕(III) [Eu(NTf₂)₃, Tf＝SO₂CF₃]作催化剂, 吲哚与醛(酮)在室温下发生亲电取代反应合成了一系列二吲哚基甲烷, 产率85%～98%. 该法反应条件温和、时间短、催化剂用量少且可以回收重复使用.     

Reactivity of 3-formyl- and 3-cyanothiochromones toward some N- and C-nucleophiles. Novel synthesis of 3-substituted 2-aminothiochromones

The reactions of 3-formylthiochromone with o-phenylenediamines, o-aminobenzenethiol, and indoles proceeded at the aldehyde group to give 3-(benzimidazol-2-yl)thiochromone, 3-(benzothiazol-2-yl)thiochromone, and 3-di(indol-3-yl)methylthiochromones, respectively. 3-Formyl- and 3-cyanothiochromones react with primary aromatic amines and phenylhydrazine to give the corresponding anils and phenylhydrazones of 3-formyl- and 2-amino-3-formylthiochromones. The reaction of 3-cyanochromones with o-phenylenediamines gave 2-amino-3-[(2-aminophenyl)iminomethyl]-4H-chromen-4-ones.     

Synthesis and solution properties of new metal-free and metallo-phthalocyanines containing four bis(indol-3-yl)methane groups

Metallo-phthalocyanines bearing four bis(indol-3-yl)methane groups were successfully prepared by reaction of the corresponding phthalonitriles with anhydrous metal salts [Zn(CH₃COO)₂, NiCl₂ and CoCl₂] in the presence of a catalytic amount of DBU in 2-(dimethylamino)ethanol. The metal-free phthalocyanine was obtained by treating a mixture of the phthalonitrile derivative in similar conditions but in the absence of a metal salt. All of these phthalocyanines are soluble in DMSO, DMF, and pyridine. The products were characterized by IR, NMR, and UV-vis spectroscopy, MALDI-TOF-MS, and thermogravimetric analysis. The aggregation properties of the phthalocyanines were investigated at different concentrations in DMSO. All the phthalocyanines showed monomeric behavior in solution.     

Efficient,Stereoselective Approach to the Synthesis of 3-(1-Phenyl-2-(Z-styrylsulfonyl)-1H-imidazol-4-yl)-2H-chromen-2-ones

Reaction of phenyl acetylene with 3-(1-aryl-2-mercapto-4-imidazolyl)-2H-1-benzopyran-2-ones (4) in the presence of sodium hydroxide in absolute ethanol led to the formation of 3-(1-phenyl-2-(Z-styrylthio)-1H-imidazol-4-yl)-2H-chromen-2-ones (6) in excellent yields. These, on further oxidation with H₂O₂/AcOH, gave the corresponding sulfones (7) with retention of stereochemistry.

Photochemical and thermal cyclizations of 4-(2-azidophenyl)-3,4-dihydropyrimidin-2-ones for the synthesis of 4-methylenepyrimidino[5,4-b]indol-2-ones

Photochemical and thermal cyclization of 4-(2-azidophenyl)-3,4-dihydropyrimidin-2-ones could afford fused indoles, such as 1,2,3a,9b-tetrahydro-4-methylenepyrimidino[5,4-b]indol-2-ones and 1,3,5,6,7a,12b-hexahydroquinazolino[9,4-b]indol-2,7-dione in high yields via nitrene electrophilic addition and rearrangement reactions.     

Reaction of 2-(2-oxoethylidene)furan-3(2H)-ones with isopropylidenehydrazides of aromatic carboxylic acids: Synthesis of 3-hydroxy-3-(2-oxoethyl)-2,3-dihydropyridazin-4(1H)-ones

3-Hydroxy-3-(2-oxoethyl)-6-phenyl-2,3-dihydropyridazin-4(1H)-ones were obtained by the reaction of methyl 3-oxo-5-phenylfuran-2(3H)-ylideneacetate or 2-[2-(4-chlorophenyl)-2-oxoethylidene]-5-phenylfuran-3(2H)-one with benzoic or p-nitrobenzoic isopropylidenehydrazides. Equilibrium C₍₅₎H and C₍₅₎H₂ tautomeric forms were detected in solutions of the 4-chlorophenyl derivatives in DMSO-d₆. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1156–1158, August, 2007.     

Novel Route for the Synthesis of 3-(Pyrrol-1-yl)-indolin-2-ones in Aqueous Micellar Medium

A high-yielding environmentally benign protocol has been developed for the synthesis of 3-(pyrrol-1-yl)-indolin-2-ones from the reaction of isatin and trans-4-hydroxy-L-proline in aqueous micellar medium. The method is operationally simple and more effective than the previous methods in terms of the yield of the products and the reaction time.     

Quantum chemical study of the transformation of 2-(N-alkylamino)-3-(indol-1-yl)-and 2-(N-alkylamino)-3-(indol-3-yl)maleimides by protic acids: Tandem hydride transfer/cyclization mechanism

The geometric parameters, the charge distribution, and the energetics of N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)-and N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimides and their conjugated acids were studied by density functional theory calculations at the B3LYP/6-31G(d) level. The mechanism of the tandem hydride transfer/cyclization sequence, which occurs after protonation of N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)-and N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimides, was analyzed. The investigation of the potential energy surface for the tandem hydride transfer/cyclization of the iminium cation that formed upon protonation revealed that the hydride transfer followed by intramolecular cyclization at position 7 of the indole fragment in N-methyl-2-(N-ethylanilino)-3-(indol-1-yl)maleimide is the preferable process, unlike alternative intramolecular cyclization involving the cationic center at the C(2) atom of the indole fragment and the benzene ring of the N-ethylaniline fragment of the indoleninium cation in N-methyl-2-(N-ethylanilino)-3-(indol-3-yl)maleimide. A study of the key intermediates of the assumed reaction mechanism demonstrated that these intermediates are actually stationary points on the potential energy surface (minima and transition states). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2069–2073, December, 2006.     

Reaction of 1-vinylpyrrole-2-carbaldehydes with phosphorus pentachloride: a stereoselective synthesis of E-2-(2-dichloromethylpyrrol-1-yl)vinylphosphonyl dichlorides

1-Vinylpyrrole-2-carbaldehydes react with phosphorus pentachloride (benzene, 10-15 °C) to afford E-2-(2-dichloromethylpyrrol-1-yl)vinylphosphonium hexachlorophosphates in up to 85% yield, which after treatment with SO₂ (benzene, rt) are converted into E-2-(2-dichloromethylpyrrol-1-yl)vinylphosphonyl dichlorides in 50-75% yields.     

Synthesis of 6H-isoindolo[2,1-a]indol-6-ones via Pd-catalyzed cycloaminocarbonylation of 2-(1H-indol-2-yl)phenyl tosylates with CO

An efficient method for preparation of substituted 6H-isoindolo[2,1-a]indol-6-ones (2) that are important structural components of a vast array of naturally occurring and pharmacologically active compounds, has been developed by the palladium-catalyzed intramolecular cycloaminocarbonylation of 2-(1H-indol-2-yl)phenyl tosylates with CO. Significantly, the intermolecular aminocarbonylation products 2-(1H-indol-2-yl)benzamides are formed when an excess of amine is used in this reaction system. Alternatively, 2-(1H-indol-2-yl)benzamides can also be synthesized by the in situ aminolysis of 2. Furthermore, treatment of 2 with hydrosilane in the presence of KOH gave the unprecedented reducing products 2-(-1H-indol-2-yl)benzyl alcohols in 75–86% yields. These results demonstrate that 6H-isoindolo[2,1-a]indol-6-ones are versatile substrates for further synthetic elaboration.     

Synthesis of 5-Hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano[2,3-c]pyridin-2-ones and Their Esters

New 5-hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano-[2,3-c]pyridin-2-ones and their esters were synthesized. The structure of obtained compounds was determined through a complete ¹H NMR analysis.     

Synthesis of Some 2-(3-Alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles as Novel Antibacterial Agents

Abstract

Herein, we describe a one-pot synthesis of some novel 2-(3-alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles (6) involving the reaction of 3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazole-1-thiocarboxamides (3) with 3-bromoacetylcoumarins (5) in the presence of sodium carbonate in ethanol. Reaction of 3 with 5 in the absence of sodium carbonate, however, resulted in the formation of 2-(3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazol-1-yl)-4-(coumarin-3-yl)thiazoles, which were subsequently dehydrated to 6 by refluxing in ethanol in the presence of sodium carbonate. The structure of the synthesized compounds (6) was confirmed by infrared (IR), mass, ¹H NMR, and ¹³C NMR spectra and elemental analysis data. Newly synthesized compounds (6) showed moderate to good activity against Gram-positive bacteria.     

(l)-Proline-catalysed novel tandem reactions of 1-substituted piperidin-4-ones with (E)-4-arylbut-3-en-2-ones: N-substituent mediated product selectivity and synthesis of novel nitrogen heterocycles

(l)-Proline-catalysed reaction of 1-alkyl/aralkylpiperidin-4-ones with (E)-4-arylbut-3-en-2-ones furnishes novel isoquinoline derivatives, with two or three rings, in good yields via tandem Robinson annulation-Michael addition(s) sequences, while the reaction of 1-arylpiperidin-4-ones with (E)-4-arylbut-3-en-2-ones affords 3-azabicyclo[3.3.1]nonan-9-ones via a tandem Michael addition-aldol reaction sequence.     

Solvent-free microwave synthesis of 4-hydroxy-3-phenylquinolin-2(1H)-ones and variants using activated arylmalonates

The disclosure herein describes the rapid synthesis of 4-hydroxy-3-phenylquinolin-2(1H)-ones and variants via a solvent-free microwave cyclocondensation reaction using di-(2,4,6-trichlorophenyl)-2-phenylmalonate, which improves the general scope of this reaction.     

Structural studies of Cu(II) binding to the novel peptidyl derivative of quinoxaline: N-(3-(2,3-di(pyridin-2-yl)quinoxalin-6-yl)alanyl)glycine

The coordination properties of the novel conjugate towards copper ions were investigated. The performed studies exhibited the unusual binding properties of the ligand molecule having two potential strong coordination sites, namely dipeptidic chain and pyridyl nitrogens. On the basis of potentiometric and spectroscopic studies the binding at the low pH values to the aromatic entity is suggested, while the rise of pH (including physiological one) yielded the dimeric head-to-tail complex formation. This stable species possesses three nitrogen donors involved in Cu(II) chelation: N(pirydyl), NH₂ and N⁻(amide).