bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantioselective 1,3‐dipolar cycloaddition reactions using complexes of (−)‐sparteine
Authors: Gucma Mirosław , Marek Gołȩbiewski W.
Published: March 2009

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Regio‐ and stereoselective 1,3‐dipolar cycloaddition of nitrile oxides to internal 2‐pentenols and α,β‐unsaturated esters catalyzed by (−) sparteine‐lanthanide complexes affords corresponding 3‐aryl‐2‐isoxazolines with enantioselectivities up to 68% ee.
Room temperature facile synthesis of quinoxalines catalyzed by amidosulfonic acid
Authors: Li Zhenjiang , Li Weisi , Sun Yingjie , Huang He , Ouyang Pingkai
Published: March 2009

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Amidosulfonic acid NH2–SO3H catalyzed direct condensations of o‐phenylenediamines with α‐diketones at room temperature in organic solvents to afford quinoxalines in excellent yields. The amidosulfonic acid as a solid acid catalyst in this preparation was efficient and recoverable.
Synthesis and structure of novel 3,4‐annelated coumarin derivatives
Authors: Dekić Milan S. , Dekić Biljana R. , Dekić Vidoslav S. , Deki Stojadin V.
Published: March 2009

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Condensation of 4‐chloro‐2‐oxo‐2H‐chromene‐3‐carbonitrile (1) with heteroarylamines 2a‐d in acetonitrile containing a catalytic amount of triethylamine followed by spontaneous intramolecular cyclization gave the novel coumarin derivatives 3a‐d, respectively. These compounds underwent acid hydrolysis giving the corresponding oxoderivatives 4a‐d. The structural assignments of the synthesized compounds were based on elemental, IR, 1H and 13C NMR analyses.
Preparation of 5‐bromo‐6‐phenylimidazo[2,1‐b][1,3,4]thiadiazol‐2‐ylamines
Authors: Safarov Saifidin , Rahmon Rahmonov , Kukaniev Muhamacho Amadovich , Schollmeyer Dieter , Karpuk Elena , Meier Herbert
Published: March 2009

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The reaction of primary or secondary amines with 2,5‐dibromo‐6‐phenylimidazo[2,1‐b][1,3,4]‐thiadiazole (5) leads to a chemoselective replacement of the 2‐Br substituent. The process represents a convenient route to the corresponding 2‐ylamines 7a‐d. Hydrazine reacts in an analogous fashion (5 → 7e). The structure determinations are based on an X‐ray crystal structure analysis and on one‐ and two‐dimensional NMR measurements.
Photodegradation of 2‐mercaptobenzothiazole disulfide and related benzothiazoles
Authors: Zajíčková Zuzana , Párkányi Cyril
Published: March 2009

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The photodegradation of 2‐mercaptobenzothiazole disulfide, 2‐mercaptobenzothiazole and benzothia‐zole was investigated. Benzothiazole was found to undergo photodimerization into 2,2′‐bibenzothiazole, and in the presence of oxygen to give two additional photoproducts ‐ 2‐hydroxybenzothiazole and 2‐methylbenzothiazole. The major degradation products of 2‐mercaptobenzothiazole are benzothiazole and 2‐benzothiazolesulfonic acid, with 2,2′‐thiobisbenzothiazole and 2‐mercaptobenzothiazole disulfide as the minor degradation products. Direct photolysis of 2‐mercaptobenzothiazole disulfide gave 2‐mercapto‐benzothiazole and in acetonitrile 2‐thiocyanatobenzothiazole was also detected. A mechanism is proposed to rationalize the formation of photodegradation products.
Studies with enaminonitriles: Synthesis and chemical reactivity of 2‐phenyl‐3‐piperidin‐1‐yl acrylonitrile under microwave heating
Authors: Salaheldin Abdellatif M. , Alphy Maryana K.
Published: March 2009

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Benzyl cyanide reacts with triethylorthoformate and piperidine in DMF solution to yield the title compound 2. This reacted with aromatic amines to yield either aminoacrylonitriles or quinoline depending on reaction conditions and substitution pattern on the aromatic amine. The reaction of compound 2 with hydrazine hydrate could only be effected in the microwave oven and resulted in the formation of aminopyrazole 7. Diazotization of 7 and coupling with an active methylene reagent afforded pyrazolo[5,1‐c]‐[1,2,4]triazine derivatives.
Synthesis of azirines containing aldehyde functionality and their utilization as synthetic tools for five membered oxazoles and isoxazoles
Authors: Brahma Sulagna , Ray Jayanta K.
Published: March 2009

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A simple and useful procedure for the synthesis of azirines containing aldehyde functionality from open chain bromo/chloro‐aldehydes at room temperature is reported. The scope of the ring expansion reaction of a number of 3‐substituted‐2‐formyl‐azirines has been examined using different oraganometallic catalysts and a variety of Lewis acids.
A facile synthesis of 5(6)‐(chloromethyl)benzimidazoles: Replacement of a sulfonic acid functionality by chlorine
Authors: Pete Béla , Szokol Bálint , Toőke László
Published: March 2009

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Valuable new synthetic intermediates, 5(6)‐(chloromethyl)benzimidazoles, were prepared by the facile elimination of sulfur dioxide under the influence of thionyl chloride from benzimidazole‐5(6)‐methane‐sulfonic acids easily obtained from (3,4‐diaminophenyl)methanesulfonic acid with formic‐, or trifluoroacetic acid. Both reaction steps involved only acidic conditions, thus the synthesis of polysubstituted 5(6)‐(chloromethyl)benzimidazoles incorporating base‐sensitive substituents became possible.
Novel piperidine nitroxide derivatives: Synthesis, electrochemical and antioxidative evaluation
Authors: Zhao Hongli , Wu Juhua , Meng Xianjiang , Zuo Shaohua , Wang Wentian , Yuan Huihui , Lan Minbo
Published: March 2009

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Novel paramagnetic materials (3a, 3b, 4a and 4b) based on heterocyclic dyes (2a and 2b) and one stable nitroxide radical (4‐NH2‐TEMPO) were synthesized. EI‐MS, elemental analysis and FT‐IR spectral data confirmed the structures of the newly synthesized compounds. In addition, the cyclic voltammetry, the antioxidant activity and reactive oxygen species (ROS) scavenging properties of these compounds are discussed in this paper.
Synthesis of 3‐substituted indoles promoted by pulverization‐activation method catalyzed by Bi(NO3)3·5H2O
Authors: Khodaei Mohammad M. , Ghanbary Parvin , Mohammadpoor‐Baltork Iraj , Memarian Hamid R. , Khosropour Ahmad R. , Nikoofar Kobra
Published: March 2009

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A new, facile, efficient, “green” and chemoselective procedure for the synthesis of indole derivatives has been developed with pulverization‐activation method catalyzed by Bi(NO3)3·5H2O (PAMC‐ Bi(NO3)3·5H2O) through grinding of indoles with aldehydes or Michael acceptors in the presence of catalytic amounts of Bi(NO3)3·5H2O under solvent‐free conditions.
New straightforward route for the synthesis of some 1‐oxa‐2‐silacyclopentane derivatives
Authors: Safa Kazem D. , Shahrivar Mohammad , Tofangdarzadeh Shahin , Hassanpour Akbar
Published: March 2009

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Tris(dimethylsilyl)methyl lithium, (HSiMe2)3CLi, reacts with allyl, phenyl, benzyl, n‐propyl and n‐butyl glycidyl ethers in THF at ‐5 °C to give 1‐oxa‐2‐silacyclopentane derivatives. It seems that ring closure is facilitated by conversion of the SiH bond into an SiO bond. Glycidyl methacrylate (GM) random copolymers with 4‐methyl‐ and 4‐methoxy styrene, synthesized by solution free radical polymerization at 70 (±1) °C with α,α‐azobis(isobutyronitrile) (AIBN) as initiator, contained pendant epoxide functions. Treatment of these with (HSiMe2)3CLi did not lead to intramolecular nucleophilic attack as found for simple epoxides.
Synthesis and molecular design of 4,8‐diaryl‐ and 4,8‐di(arylethynyl)pyrido[4,3‐d]pyrimidines: Potential applications in nonlinear optics. Diazines Part 49
Authors: Busch Alexandrine , Turck Alain , Plé Nelly
Published: March 2009

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Using metallation and cross‐coupling reactions, we report the synthesis of a new series of push‐pull compounds with a pyrido[4,3‐d]pyrimidine system as the central core. Two of them were tested and their NLO properties highlighted. Incorporation of triple and double bonds as spacer between the central core and the substituted aryl groups has been performed to allow an extension of conjugation.
Macrocyclic compounds from benzenedithiols and triazine: Modification of tetrathiacalix[4]arene
Authors: Alam Ashraful , Yamaguchi Miharu , Yamamoto Tatsuya , Nakajo Shiduko , Ogawa Satoshi , Sato Ryu
Published: March 2009

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Synthesis of macrocyclic compounds having benzenedithionate and triazine moieties was achieved by an efficient fragment coupling approach. In the solid state, they adopted 1,3‐alternate conformations. Combination of two pairs of electron rich and electron poor units, and ortho‐ortho and/or ortho‐meta connections of sulfur atoms with aromatic carbons were novel features of the macrocycles.
Studies on the reaction of N‐(3‐carbethoxy‐4,5,6,7‐tetrahydrobenzo[b]thien‐2‐yl)‐N′‐phenylthiourea with hydrazine hydrate (Part 1)
Authors: El‐Sherief Hassan A. H. , El‐Naggar Galal M. , Hozien Zeinab A. , El‐Sawaisi Suliman M.
Published: March 2009

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The reaction of N‐(3‐carbethoxy‐4,5,6,7‐tetrahydrobenzo[b]thien‐2‐yl)‐N′‐phenylthiourea (1) with hydrazine hydrate in 1‐butanol afforded a mixture of compounds 2, 3 and 4. Treatment of 3 and 4 with nitrous acid gave 6 and 8 respectively, while reactions of 3 with acetylacetone gave 7. Synthesis of tetracyclic compounds 9a‐f and 11 from the reactions of 3 with ethyl orthoformate or appropriate acids, acid chloride, carbon disulphide and/or ethyl chloroformate. Also its reaction with isothiocyanate derivatives gave the corresponding thiosemicarbzides 12a,b which on, refluxing in alcoholic KOH gave the unexpected tetracyclic products 14a,b. Similarly the tetracyclic compounds 16a‐e and 19 were obtained by cyclization of 4 and 18 respectively.
Synthesis and stereochemistry of 3‐acetyl‐5‐aminospiro[1,3,4‐thiadiazoline‐2,4′‐thioflavans]
Authors: Somogyi László , Batta Gyula , Gunda Tamás E. , Bényei Attila Cs.
Published: March 2009

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Under acetylating conditions racemic thioflavanone thiosemicarbazones cyclize into racemic 3‐acetyl‐spiro[1,3,4‐thiadiazoline‐2,4′‐thioflavans] and a racemic 3‐acetylspiro[1,3,4‐oxadiazoline‐2,4′‐thioflavan] with trans O(1) or S(1) and Ph(2′eq). Hindered rotation of the endocyclic N(3) acetyl group spirothia‐diazolines caused the formation of isomers separable by HPLC. X‐ray diffraction analyses, 1H‐, 13C‐, and 15N NMR measurements as well as MOPAC QM calculations were performed to reveal the structures of these isomers.
New one step synthesis of 3,5‐disubstituted pyrazoles under microwave irradiation and classical heating
Authors: Outirite Moha , Lebrini Mounim , Lagrenée Michel , Bentiss Fouad
Published: March 2009

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A convenient one pot procedure for the synthesis of 3,5‐disubstituted pyrazoles by condensation of chalcones, hydrazine hydrate and sulfur in ethanol under microwave irradiation and conventional heating method is reported. The hydrogen sulfide is produced during the reaction. The pyrazoles are obtained in good yields and excellent state of purity. The structures of new compounds were confirmed by IR, 1H, and 13C NMR, MS and elemental analysis.
Synthesis of a new class of spiro heterocycles
Authors: Padmavathi Venkatapuram , Sudheer Kaveti , Subbaiah Dandu Rangayapalle Chinna Venkata , Mahesh Konda
Published: March 2009

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A new class of spiro heterocycles viz., spiropyrazolidinediones, isoxazolidinediones, pyrimidinetriones or thioxopyrimidinediones are developed from methyl 3‐aryl‐2‐(Z‐arylethenenylsulfonyl)acrylate by double Michael addition reaction with dimethyl malonate followed by cyclocondensation with appropriate nucleophiles.
Homolytic alkylation of some 3,4‐quinolinediyl bis‐sulfides under minisci reaction conditions
Authors: Maślankiewicz Andrzej , Michalik Ewa , Ciunik Zbigniew
Published: March 2009

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Reaction of hydrogen sulfate of 3,4‐quinolinediyl bis‐sulfides 1a, 2a, 3a, and 4a with isopropyl and cyclohexyl radicals formed from alkyl iodide/hydrogen peroxide/DMSO/Fe++ salt system took place at α‐quinolinyl position and led to the respective mono‐ and dialkyl derivatives 1b‐e, 2b‐e, 3b,c, and 4b,c. Action of sodium methoxide towards isopropyl derivatives 1b,c and 2b,c caused the 1,4‐dithiin ring opening to form (after S‐methylation) derivatives of 3,4′‐ and 3,3′‐diquinolinyl sulfides 6a,b and 7a,b.
An efficient, “green” approach to aryl amination of cyanuric chloride using acetic acid as solvent
Authors: Kolmakov Kirill A.
Published: March 2009

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Acetic acid is an inexpensive and environmentally friendly solvent for facile, clean and high‐yielding aryl amination of cyanuric chloride with aromatic amines, including nitroanilines. Aryl amination in acetic acid medium and isolation protocol are greatly simplified as compared to previously reported procedures. Under proper conditions, it is possible to attach the same or different aniline residues in a controlled way to obtain in excellent yields symmetrical and unsymmetrical 1,3,5‐triazine derivatives, respectively.
4H‐1‐Benzopyrans by a tandem SN2‐SNAr reaction
Authors: Bunce Richard A. , Rogers David , Nago Takahiro , Bryant Scott A.
Published: March 2009

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Treatment of 2‐fluoro‐5‐nitrobenzyl bromide with active methylene compounds in the presence of excess potassium carbonate in acetone leads to the formation of highly functionalized 4H‐1‐benzopyrans by a tandem SN2‐SNAr reaction sequence. The reaction works well with β‐keto esters, β‐keto sulfones, β‐keto phosphine oxides, β‐keto phosphonates and β‐keto nitriles. The reaction is simple to perform and affords products in 50‐92% yields.
Benzo‐fused heterocycles and carbocycles by intramolecular SNAr and tandem SN2‐SNAr reactions
Authors: Bunce Richard A. , Nago Takahiro , Sonobe Nathan , Slaughter Legrande M.
Published: March 2009

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Benzo‐fused heterocyclic and carbocyclic systems have been synthesized by intramolecular SNAr and tandem SN2‐SNAr reactions. Treatment of 3‐(2‐fluoro‐5‐nitrophenyl)‐1‐propanol with sodium hydride in N,N‐dimethylformamide gave 6‐nitrochroman in 80% yield by an intramolecular SNAr reaction. Treatment of 2‐(3‐bromopropyl)‐1‐fluoro‐4‐nitrobenzene with benzylamine in N,N‐dimethylformamide gave 1‐benzyl‐6‐nitrotetrahydroquinoline in 98% yield by a tandem SN2‐SNAr reaction. Finally, in a similar process, reaction of this same bromide with dimethyl malonate under basic conditions gave 1,1‐bis(methoxycarbonyl)‐6‐nitro‐1,2,3,4‐tetrahydronaphthalene in 80% yield. Further studies exploring ring size effects are also presented.
Three possible products from the reactions of gewald's amide with aromatic aldehydes
Authors: Dzhavakhishvili Sergey G. , Gorobets Nikolay Yu. , Musatov Vladimir I. , Desenko Sergey M. , Paponov Boris V.
Published: March 2009

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Transformations of 2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxamide (Gewald's amide) in the reactions with aromatic aldehydes were studied. Efficient methods for synthesis of three possible types of products: 2‐aryl‐5,6,7,8‐tetrahydro[1]benzothieno[2,3‐d]pyrimidin‐4(3H)‐one, 2‐(1‐arylmethylidene‐amino)‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxamide and 2‐aryl‐2,3,5,6,7,8‐hexahydro[1]benzo‐thieno[2,3‐d]pyrimidin‐4(1H)‐one derivatives were developed. All the products were easily isolated by filtration in very good overall yields. Mutual transformations of these compounds were also studied.
Iodine catalyzed synthesis of α,α'‐bis(substituted benzylidene)‐1‐carbethoxy‐4‐piperidone
Authors: Ameen Mohame D. A. , Ahmed Essam, Kh.
Published: March 2009

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A facile and efficient method for the preparation of α,α′‐bis(substituted benzylidene)‐1‐carbethoxy‐4‐piperidone is described using iodine as a catalyst in acetonitrile. The reaction proceeds rapidly at room temperature, giving high yields of products.
A ‘one pot’ synthesis of 2‐aryl‐4H‐1‐benzopyran‐4‐ones under coupled microwave phase transfer catalysis (PTC) and ultrasonic irradiation PTC
Authors: Pathak Vijai N. , Varshney Bindu , Gupta Ragini
Published: March 2009

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A ‘one pot’ synthesis of 2‐aryl‐4H‐1‐benzopyran‐4‐ones(3a‐3f)is being reported. A mixture ofo‐hydroxyacetophenone, aroyl chloride, powderedn‐tetrabutylammonium hydrogensulphate (n‐TBAHSO4) and potassium hydroxide (KOH) were either irradiated by microwaves or sonicated in an ultrasonic cleaning bath to afford flavones directly. On the contrary, conventional liquid‐liquid Phase Transfer Catalysis (PTC) using benzene as organic phase and aqueous KOH as the second phase afforded first β‐diketones in accordance with Baker‐Venkataraman synthesis which upon cyclization byp‐toluenesulphonic acid (p‐TSA) gave desired flavones in the next step. PTC coupled with microwaves or ultrasound show enhanced yields, the clean reaction conditions require less time, and have easier workup protocol. All synthesized compounds were characterized by their Proton Magnetic Resonance (PMR), IR, FAB Mass and elemental analyses.
Synthesis of 8‐hydroxyquinolines with amino and thioalkyl functionalities at position 4
Authors: Omar Walaa A. E. , Heiskanen Juha P. , Hormi Osmo E. O.
Published: March 2009

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Six 8‐hydroxyquinolines with amino and thioalkyl functionalities at position 4 have been prepared. The synthesis starts with chlorination of the readily available 4‐hydroxy‐8‐tosyloxyquinoline to give 4‐chloro‐8‐tosyloxyquinoline in 94% yield. Treatment of the 4‐chloro‐8‐tosyloxyquinoline with sulphur and nitrogen nucleophiles produces the target 4‐amino and 4‐thioalkyl‐8‐hydroxyquinolines in more than 70% yield. In case of sulphur nucleophiles and pyrrolidine, the removal of the protecting tosyl group at position 8 occurs simultaneously with the substitution of chlorine at position 4.
A novel one‐pot oxidative deformylation of N‐formyldihydroquinolines employing ferric chloride hexahydrate. Synthesis of 4‐chloro‐2‐phenylquinolines and 4‐chloro‐2‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)quinolines
Authors: Kumar Kalvi. Hemanth , Perumal Paramasivan. T.
Published: March 2009

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A novel versatile one‐pot oxidative deformylation approach has been developed to synthesize 4‐chloro‐2‐phenylquinolines and 4‐chloro‐2‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)quinolines from the corresponding N‐formyldihydroquinolines.
Regioselective synthesis of N(3)‐ and O‐acylmethyl derivatives of 2‐methylthio‐4(3H)‐quinazolinone
Authors: Burbuliene Milda M. , Mazeikaite Rita , Vainilavicius Povilas
Published: March 2009

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Reaction of 2‐methylthio‐4(3H)‐quinazolinone with chloroacetone, ω‐bromoacetophenone or ethyl bromoacetate in different solvents (methanol, acetonitrile, dimethylformamide and toluene) using sodium methoxide or potassium carbonate as a base were studied. Regioselective N(3)‐alkylation took place in toluene using potassium carbonate, whereas in dimethylformamide O‐acylmethyl derivatives were obtained. However chloroacetone reacted with 2‐methylthio‐4(3H)‐quinazolinone under various conditions to give a mixture of N(3)/O‐isomers.
Synthesis of two potential heterocyclic amine food mutagens
Authors: Tanga Mary J. , Kozocas Joseph A. , Tochimoto Todd K.
Published: March 2009

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The syntheses of two potential food mutagens formed during cooking, 2‐amino‐3,6,7‐trimethyl‐3H‐imidazo[4,5‐b]pyridine (1) and 2‐amino‐3,6,7‐trimethyl‐3H‐imidazo[4,5‐c]pyridine (2), are described.
Synthesis of some 3‐aryl‐1H‐isochromene‐1‐thiones
Authors: Saeed Aamer , Ashraf Zaman
Published: March 2009

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A rapid microwave‐accelerated thionation of some 3‐substitued isocoumarins to corresponding 1‐thio‐isocoumarins was achieved employing Lawesson's reagent under solventless conditions.
A new, efficient and chemoselective one‐pot protocol for synthesis of 4‐arylidene‐2‐phenyl‐5(4H)‐oxazolones from aryl aldehyde bisulfite adducts promoted by POCL3
Authors: Khosropour Ahmad R. , Khodaei Mohammad M. , Jomor Seyed J. Hoseini
Published: March 2009

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A one‐pot procedure for the synthesis of 4‐arylidene‐2‐phenyl‐5(4H)oxazolones directly from aryl aldehyde bisulfite adducts in the absence of Ac2O in good to excellent yields using phosphoryl chloride is reported. In addition, the observed chemoselectivity can be considered as a noteworthy advantage of this method.
Cyclization of dialkylpropyn‐1‐yl(allyl)(3‐isopropenylpropyn‐2‐yl)ammonium bromides and water‐base cleavage of 2,2‐dialkyl‐5‐methyl‐2,6,7,7a‐tetrahydro‐1h‐isoindolium and 2,2‐dialkyl‐5‐methylisoindolinium bromides
Authors: Chukhajian Emma H. , Nalbandyan Martiros K. , Gevorkyan Hasmik R. , Chukhajian Eliza H. , Panosyan Henrik A. , Ayvazyan Armen G. , Tamazyan Rafael A.
Published: March 2009

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Dialkylpropyn‐1‐yl(or allyl)(3‐isopropenylpropyn‐2‐yl)ammonium bromides under base‐catalyzed condition instantly undergo intramolecular cyclization. The cyclization of dialkylpropyn‐1‐yl(3‐isopropenylpropyn‐2‐yl)ammonium bromides leads to the formation of 2,2‐dialkyl‐5‐methylisoindolinium salts. In case of allyl analogs, instead of the expected 2,2‐dialkyl‐6‐methyl‐3a,4‐dihydroisoindolinium salts their isomeric forms ‐ 2,2‐dialkyl‐5‐methyl‐2,6,7,7a‐tetrahydro‐1H‐isoindolium bromides are obtained. In alkaline medium they are transform into the dihydroisoindolinium salts, the cleavage of which in two directions ‐ 1,2 and 1,6 leads to the mixture of isomeric dialkyl‐1,4‐dimethyl‐ and 2,4‐dimethylbenzyl‐amines.

Study of the behavior of 2,2‐dialkyl‐5‐methylisoindolinium salts under conditions of water‐base cleavage showed, that only spiro[5‐methylisoindolyn]morpholinium bromide undergoes 1,2‐elimination, forming 5‐methylisoindoline 2‐vinyl ethyl ester.
Synthesis and bioactivity of 6‐bromo‐2‐(substituted)‐3‐(1‐phenyl‐ethyl)‐ 3,4‐dihydro‐1H‐ isophosphinoline 2‐chalcogenides
Authors: Srinivasulu K. , Babu B. Hari , Kumar K. Suresh , Reddy C. Bhupendra , Raju C. Naga , Rooba D.
Published: March 2009

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Synthesis of 6‐bromo‐2‐(substituted)‐3‐(1‐phenyl‐ethyl)‐3,4‐dihydro‐1H‐isophosphinoline 2‐chalco‐genides derivatives (6) were synthesized from 2‐[(1‐phenylethylamino)methyl]‐4‐bromophenol (1) by reaction with aryl/alkyl phosphoro dichloridates (2) in the presence of triethylamine at 55°C to 60°C to obtained the title compounds (6a‐g). The title compounds (6h‐j), were prepared via intermediate route. Few other title compounds (8a‐c) were accomplished through a two step synthetic route involving 1 with dichlorophenyl phosphine (2a) and dichloroethyl phosphine (2a,b) in the presence of triethylamine in dry toluene under N2 atmosphere to form the corresponding trivalent phosphorus intermediate (7). In the second step they were further converted to the corresponding chalcogenides 8a‐c by reaction with hydrogen peroxide, sulfur and selenium respectively. They exhibited significant antibacterial, fungal and insecticidal activity.
Studies towards the synthesis of bicyclomycin precursors: Synthesis of N,N′‐disubstituted 2,5‐diketopiperazines in solution and on solid phase
Authors: Fryszkowska Anna , Ostaszewski Ryszard
Published: March 2009

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The synthesis of 3‐(hydroxyalkyl)‐N,N′‐disubstituted 2,5‐diketopiperazine derivatives ‐ compounds required for the bicyclomycin analogues preparation ‐ has been studied. The use of various oxo components in the Ugi multicomponent reaction (U‐MCR) has been evaluated. The first example of an semicyclic O,O‐acetal employed as an aldehyde equivalent in the U‐MCR has been reported. The preparation and the synthetic application of Wang resin‐bound aliphatic aldehydes in the synthesis of 2,5‐diketopiperazine skeleton has also been described.
Efficient synthesis of 5,10,15‐triarylcorroles using amberlyst 15 under solvent‐free conditions
Authors: Kumari Pratibha , Chauhan Shive M. S.
Published: March 2009

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An efficient and convenient synthesis of 5,10,15‐triarylcorroles by the condensation of aryl aldehydes with pyrrole catalyzed by Amberlyst 15 followed by oxidative cyclization with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) at room temperature has been reported. Amberlyst 15 is more efficient catalyst under solvent free conditions and DDQ is more suitable oxidant in dichloromethane than those of other catalysts and oxidants, respectively, for the synthesis of corroles at room temperature.
An interesting cyclization of N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide
Authors: Ma Nianchun , Wu Kemei , Huang Liang
Published: March 2009

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Under Lewis acid condition, N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide undergoes elegant double cyclizations to give interesting products.
Synthesis of multi‐substituted dibenzo[b,d]furan
Authors: Gajera Jitendra M. , Gopalan Balasubramanian , Yadav Pravin S. , Patil Sandip D. , Gharat Laxmikant A.
Published: March 2009

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The synthesis of multi‐substituted dibenzo[b,d]furan derivatives 7a‐b and 11a‐b from readily available starting materials is described. These compounds are important intermediates for synthesis of molecules having wide therapeutic applications.
Preparation of halogenated derivatives of thiazolo[5,4‐d]thiazoleviadirect electrophilic aromatic substitution
Authors: Benin Vladimir , Yeates Alan T. , Dudis Douglas
Published: March 2009

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Chlorination and bromination reactions of thiazolo[5,4‐d]thiazole led to the generation of its mono‐ and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4‐d]thiazole ring system. X‐ray analysis demonstrates that both 2‐bromothiazolo[5,4‐d]‐thiazole and 2,5‐dibromothiazolo[5,4‐d]thiazole are planar structures, with strongly manifested π‐stacking in the solid state. Theoretical analysis of the pyridine‐catalyzed halogenation (MP2/6‐31+G(d)andB3LYP/6‐31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C‐halogenation with N‐halopyridine as electrophile; 2) C‐halogenationviaintermediate N‐halogenation, and 3) C‐halogenation following an addition ‐ elimination pathway, with intermediate formation of a cyclic halonium ion. The theoretical studies suggest that the direct C‐halogenation is the favored mechanism.
Synthesis and characterization of substituted (benzo[b]thiophen‐2‐yl)‐4‐methyl‐4,5‐dihydro‐1H‐imidazol‐5‐ones
Authors: Sedlák Miloš , Drabina Pavel , Lánský Václav , Svoboda Jiří
Published: March 2009

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Reactions of 3‐chlorobenzo[b]thiophene‐2‐carbonyl chloride with 2‐alkyl‐2‐aminopropanamides have been used to prepare a series of carboxamides 1a‐d (yields 61‐85%). The products were submitted to base‐catalysed ring closure reactions to give the corresponding 4,5‐dihydro‐1H‐imidazol‐5‐ones 2a‐d (yields 69‐97%). By N‐methylation and N‐benzylation were prepared the corresponding 1‐alkyl derivatives 3a(91%) and 3b (85%). These two alkyl derivatives were studied from the standpoint of potential replacement of 3‐chlorine substituent by piperidine via the Buchwald‐Hartwig reaction. It was found that the reaction gives besides except required products of C‐N coupling 5a (14%) and 5b (12%) also products of reductive dechlorination 4a (max. 57%) and 4b (max. 56%). The reductive dechlorination product 4a is formed exclusively (42%) if butyl‐di‐(1‐adamantyl)phosphine (BDAP) is used.
Synthesis of 1,3‐thiazole and 1,2,4‐oxadiazole substituted spiro[3H‐indole‐3,2′‐thiazolidine]‐2,4′(1H)‐diones
Authors: Mashelkar Uday C. , Rane Deepak M. , Kenny Rajesh S.
Published: March 2009

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Some new derivatives of spiro[3H‐indole‐3,2′‐thiazolidine]‐2,4′(1H)‐dione with the heterocyclic ring such as substituted thiazole and 1,2,4‐oxadiazole attached to the indolinone ring via CH2 linkage has been synthesized in moderate yields. The synthesis have been carried out by making use of the reactivity of the NH group of the indolinone moiety present in spiro[3H‐indole‐3,2′‐thiazolidine]‐2,4′(1H)‐dione.
Reaction of β‐dimethylaminovinyl ketones with hydroxylamine: A simple and useful method for synthesis of 3‐ and 5‐substituted isoxazoles
Authors: Rosa Fernanda A. , Machado Pablo , Bonacorso Helio G. , Zanatta Nilo , Martins Marcos A. P.
Published: March 2009

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The regioselective synthesis of 3‐ and 5‐substituted‐isoxazoles from the reaction of β‐dimethyl‐aminovinyl ketones [R‐C(O)CHCH‐NMe2, where R  Ph, MeO‐4‐C6H4, F‐4‐C6H4, Cl‐4‐C6H4, Br‐4‐C6H4, O2N‐4‐C6H4, fur‐2‐yl, thien‐2‐yl, pyrrol‐2‐yl, Et and CCl3] and hydroxylamine hydrochloride varying only the reaction conditions (with and without the addition of pyridine) is reported.
Synthesis, characterization and studies of new 3‐benzyl‐4H‐1,2,4‐triazole‐5‐thiol and thiazolo[3,2‐b][1,2,4]triazole‐5(6H)‐one heterocycles
Authors: Sarhan Abdelwareth A. O. , Elsherif Hassa N. A. H. , Mahmoud Abdalla M. , Habib Osama M. A.
Published: March 2009

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3‐Benzyl‐4‐phenyl‐1,2,4‐triazole‐5‐thiol (1) was synthesized and used as starting material for preparation of 1,2,4‐triazole bearing substituted thiosemicarbazides moiety (4a‐d) in high yields. The thiosemicarbazides4a‐dwere cyclized in basic medium to give two triazole rings linked by thiomethylene group (5a‐d), while cyclization of thiosemicarbazides4a‐dwith chloroacetyl chloride in the presence of CHCl3and K2CO3afforded the thiazolidinone derivatives6a‐d. The reaction of thiosemicarbazides4a‐cwith phenacyl bromide in the presence of EtOH and fused CH3COONa gave the corresponding thiazoline ring systems7a‐c. Condensation of the 3‐benzyl‐1,2,4‐triazole‐5(1H)‐thiol (1) with chloroacetic acid and aromatic aldehydes (8a‐g) in boiling acetic acid/acetic anhydride mixture in the presence of fused sodium acetate gave one single isomer only, which might be9a‐gor10a‐g. Upon application of Micheal addition reaction on compounds9a‐ewith cyclic secondary amines such as piperidine or morpholine the 2‐benzyl‐6‐(α‐amino‐aryl/methyl)‐1,3‐thiazolo[3,2‐b][1,2,4]‐triazol‐5‐ols (11a‐j) were obtained in good yields The structure of all new compounds were determined using both spectral and elemental analyses.
Synthesis and liquid crystalline properties of novel pyridine derivatives
Authors: Itahara Toshio
Published: March 2009

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The treatment of 4‐hydroxypyridine with cholestery p‐(ω‐bromoalkyloxy)benzoates in N,N‐dimethylformamide containing K2CO3 gave cholestery p‐[ω‐(4‐pyridyloxy)alkyloxy]benzoates, which exhibited liquid crystalline properties
Convenient syntheses of 5‐[(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)methyl]‐1,3,4‐oxadiazole‐2(3H)thione and N‐substituted 2‐amino‐5‐[(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)methyl]‐1,3,4‐thiadiazoles
Authors: Mirzaei Javad , Pirelahi Hooshang , Amini Mohsen , Shafiee Abbas
Published: March 2009

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Oxidation of metronidazole (4) with sodium dichromate yielded the corresponding 2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)acetic acid (5) which was esterified with 1‐butanol to give butyl 2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)acetate (8). Reaction of the latter with hydrazine hydrate gave 2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)acetohydrazide (9). Compound 5‐[(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)methyl]‐1,3,4‐oxa‐diazole‐2(3H)‐thione (10) could be obtained through the reaction of compound 9 with carbon disulfide in basic medium. Subsequent alkylation of compound 10 afforded alkyl 2‐(5‐[(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)methyl]‐1,3,4‐oxadiazol‐2‐ylthio)acetate (11) in good yield. Reaction of hydrazide 9 with substituted isothiocynate yielded 1‐[2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)acetyl]‐4‐aryl(or ethyl)thiosemicarbazide (12) which was cyclized in acidic media to N‐substituted 2‐amino‐5‐[(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)methyl]‐1,3,4‐thiadiazole (13).
Synthesis of new 3‐(trifluoromethyl)‐1H‐indoles by reduction of trifluoromethyloxoindoles
Authors: Bastos Moônica M. , Mayer Lúcia M. U. , Figueira Elza C. S. , Soares Marcio , Boechat Núbia , Kover Warner B.
Published: March 2009

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This work describes the synthesis of new 3‐trifluoromethylindoles. Different isatins were trifluoromethylated using (trifluoromethyl) trimethylsilane (Me3SiCF3) as a nucleophilic agent giving new 3‐hydroxy‐3‐(trifluoromethyl)indolin‐2‐one. Different “one‐step” procedures to transform the latter compounds into the reduced indoles were attempted, but failed. For the synthesis of the new trifluoromethylindoles the corresponding 2‐oxo‐3‐(trifluoromethyl)indoles were reduced using borane/THF complex to furnish 3‐(trifluoromethyl)indolin‐3‐ol that additionally were dehydrated using thionyl chloride in pyridine to give excellent yields of the desired products.
Studies with 2‐arylhydrazononitriles: Further investigations on reactivity of 2‐arylhydrazononitriles towards hydroxylamine
Authors: Riyadh Sayed M. , Al‐Matar Hamad M. , Elnagdi Mohamed H.
Published: March 2009

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The utilization of arylhydrazononitriles (6‐9) for synthesis of azoles is demonstrated. Thus, arylazomalononitriles (6) reacted with hydroxylamine hydrochloride to afford isoxazol‐5‐imine (10), amidoxime (12) and bis‐amidoxime (13) derivatives depending upon both the reaction conditions and molar ratio employed. 2‐Thiazolyl‐2‐arylhydrazononitriles (7) and cyanoformazans (8) gave 1,2,3‐triazole derivatives (15) and (17) respectively upon treatment with hydroxylamine hydrochloride and concomitant loss of water molecule. Formation of novel 1,2,4‐triazin‐5(4H)‐one derivatives (21) has efficiently been carried out by treatment of amidoximes (18) with acetic anhydride in acetic acid.
A convenient synthesis and biological activities of novel 6‐aryl‐3‐(1,2,3,4‐tetrahydroxybutan‐1‐yl)‐7H‐1,2,4‐triazolo‐[3,4‐b][1,3,4]thiadiazines
Authors: Ye Xiao‐Xia , Zhang Jin , Zhang An‐Jiang , Zhang Li‐Xue
Published: March 2009

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A series of novel 6‐aryl‐3‐(1,2,3,4‐tetrahydroxybutanol‐1‐yl)‐7H‐1,2,4‐triazolo[3,4‐b][1,3,4]thiadiazines were easily synthesized in high yields by means of the reactions of 4‐amino‐5‐(1,2,3,4‐tetrahydroxybutyl)‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thione (1) with substituted ω‐bromoacetophenones or ω‐chloroacetophenone. Nearly all of the title compounds possess plant growth‐promoting activities.
Synthesis and biological evaluation of novel methylene‐bisthiazolidinone derivatives as potential nematicidal agents
Authors: Srinivas A. , Nagaraj A. , Reddy Ch. Sanjeeva
Published: March 2009

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In a one pot procedure, a series of novel methylene‐bis‐thiazolidinone derivatives 5 and 6 was prepared by condensation of 5‐(3‐formyl‐4‐methoxybenzyl)‐2‐methoxybenzaldehyde 3 with mercapto acids and primary aromatic amines 4 in presence of ZnCl2 under both microwave irradiation and conventional heating conditions. High yields are achieved even on a gram scale, while reaction times are considerably shortened under microwave irradiation compared to conventional heating conditions. Characterization of new compounds has been done by means of IR, NMR, MS and elemental analysis. The nematicidal and antibacterial activity of the compounds has also been evaluated.
Synthesis of novel 5,7‐disubstituted 8‐hydroxyquinolines
Authors: Himmi Banacer , Kitane Saïd , Eddaif Abdelhamid , Joly Jean‐Pierre , Hlimi Fouzia , Soufiaoui Mohamed , Bahloul Abdelmejid , Sebban Abdelfatah
Published: March 2009

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Seven new 5,7‐disubstituted oxine derivatives have been synthesized via a Mannich reaction between a sec. amine (e.g. piperidine, pyrrolidine, morpholine, or dibenzylamine,) and 5‐cyano or 5‐azidomethyl‐8‐hydroxyquinoline, which were respectively obtained by nucleophilic displacement of 5‐chloromethyl‐8‐hydroxyquinoline by cyanide or azide anions. In all cases, a single product was isolated in medium to fair yield and characterized on the basis of 1H and 13C‐NMR, MS and IR spectrometric data. The X‐ray structure of the product obtained from 5‐cyanomethyl‐8‐hydroxyquinoline and piperidine is also reported.
I2‐catalyzed reactions of schiff base and alkyl aldehyde towards benzo[f]quinoline derivatives
Authors: Li Qing , Yao Chang‐Sheng , Zhang Mei‐Mei , Tu Shu‐Jiang , Wang Xiang‐Shan
Published: March 2009

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A mild, efficient, and general method for the synthesis of benzo[f]quinoline derivatives via a molecular iodine‐catalyzed reaction of Schiff base with alkyl aldehydes has been described. The structure of 3o was confirmed by X‐ray diffraction study.
Synthesis and biological activities of novel 1,3‐bis[substituted‐pyridyl (thiazolyl)methyl]‐2‐substitutedmethylideneimidazolidines
Authors: Yan Man , Luo Zai‐Gang , Zhu Xiao‐Fei , Shi De‐Qing
Published: March 2009

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A series of novel 1,3‐dissubstitutedpyridyl(thiazolyl)methyl‐2‐substituted‐methylideneimidazolidine derivatives 2 and 4 were designed and synthesized via the N‐alkylation of the disubstituted heterocyclic ketene aminal derivative 1. When 1 (R = CN, R' = COOC2H5) was used as the starting materials, mono N‐alkylated reaction can take place in good yields owing to the presence of the intramolecular hydrogen bond. However, as for 1 (R = R' = CN), it is difficult to obtain pure mono N‐alkylated product. The structures of the target compounds were confirmed by IR, 1H NMR, EI‐MS and elemental analyses, and, in the case of 2c, by single crystal X‐ray diffraction. The preliminary bioassay indicated that some of the title compounds possess moderate fungicidal and insecticidal activity.
An efficient microwave‐assisted synthesis furo[3,4‐b]‐[4,7] phenanthroline and indeno[2,1‐b][4,7]phenanthroline derivatives in water
Authors: Shi Feng , Zhou Dianxiang , Tu Shujiang , Shao Qingqing , Li Chunmei , Cao Longji
Published: March 2009

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A series of furo[3,4‐b][4,7]phenanthroline and indeno[2,1‐b][4,7]phenanthroline derivatives were synthesizedviaa three‐component reaction of aromatic aldehydes, 6‐aminoquinoline and either tetronic acid or 1,3‐indanedione in water, under microwave irradiation without use of any catalyst. This green procedure offers several advantages including operational simplicity, clean reaction, and increased safety for small‐scale high‐speed synthesis.
Heterocondensed thiophenes and thiazoles by THORPE‐ZIEGLER cyclization
Authors: Gruner Margit , Böttcher Gesine , Gewald Karl
Published: March 2009

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The syntheses of novel thieno‐pyridones, thiazolo‐pyridones, thiazolo‐pyridines and amino‐ and diamino‐dieno‐pyridines were described. Simultaneously, it was demonstrated that in these compounds and in the related 3‐aminothiophenes the replacement of the methylthio by the morpholino group is possible. The structures were characterized using 1H‐, 13C‐NMR, IR and elemental analysis.
A green and efficient synthesis of furo[3,4‐e]pyrazolo[3,4‐b]‐pyridine derivatives in water under microwave irradiation without catalyst
Authors: Shi Feng , Tu Shujiang , Jiang Bo , Li Chunmei , Zhou Dianxiang , Shao Qingqing , Cao Longji , Wang Qian , Zhou Jianfeng
Published: March 2009

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A series of furo[3,4‐e]pyrazolo[3,4‐b]pyridine analogues of podophylloxin were synthesized via three‐component reactions of aldehydes, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine and tetronic acid in water under microwave irradiation without catalyst. This efficient synthesis not only offers an economical and green synthetic strategy to this class of significant compounds but also enriches the investigations on microwave‐assisted synthesis in water.
Synthesis and biological evaluation of novel methylene‐bis‐[1,5]‐benzodiazepines
Authors: Raghu M. , Nagaraj A. , Reddy Ch. Sanjeeva
Published: March 2009

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A series of novel methylene‐bis‐chalcones 3 was prepared by the reaction of 5‐(3‐formyl‐4‐hydroxybenzyl)‐2‐hydroxy benzaldehyde 2 with different acetophenones, subsequent treatment of compound 3 with an appropriate o‐phenylenediamine gave the corresponding methylene‐bis‐[1,5]‐benzodiazepines 4/5 in good yields. Characterization of the new compounds has been done by means of IR, 1H NMR, MS and elemental analyses. The antibacterial and antifungal activity of the compounds has also been evaluated.
Synthesis of some novel methylene‐bis‐pyrimidinyl‐spiro‐4‐thiazolidinones as biologically potent agents
Authors: Srinivas A. , Nagaraj A. , Reddy Ch. Sanjeeva
Published: March 2009

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A series of novel methylene‐bis‐pyrimidinyl‐spiro‐4‐thiazolidinones 6a‐h have been synthesized by cyclocondensation of thioglycolic acid with methylene‐bis‐(N‐cyclohexylidene‐N‐pyrimidine) 5a‐h, which in turn have been prepared by the reaction of cyclohexanone with methylene‐bis‐2‐aminopyrimidines 4a‐h, which are prepared by the reaction of guanidine hydrochloride with methylene‐bis‐chalcones 3a‐h. The compounds 3a‐h have been synthesized by the reaction of 5‐(3‐formyl‐4‐hydroxybenzyl)‐2‐hydroxybenzaldehyde 2 with various acetophenones in presence of KOH. The compound 2 is prepared by the reported method. The structures of the compounds synthesized have been confirmed by their elemental analysis and spectral data. Their antibacterial and antifungal activities have also been evaluated.
Green multicomponent synthesis of 1,2‐dihydro‐pyrimido[1,2‐a]‐benzimidazole‐3‐carbonitrile
Authors: Liu Guangmin , Shao Qingqing , Tu Shujiang , Cao Longji , Li Chunmei , Zhou Dianxiang , Han Baoping
Published: March 2009

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1,2‐dihydro‐pyrimido[1,2‐a]benzimidazole‐3‐carbonitrile derivatives were synthesized via the three‐component reaction of aldehyde, malonodinitrile and 2‐aminobenzimidazole in water under microwave irradiation. The new protocol has the advantages of excellent yield, low cost, reduced environment impact, wide scope and convenient procedure.
Synthesis of a new class of bisheterocycles from phenacylsulfonylacetic acid methyl ester
Authors: Padmavathi Venkatapuram , Mohan Annaji Venkata Nagendra , Mahesh Konda
Published: March 2009

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Novel bisheterocycles, 1,2,3‐selenadiazoles, thiadiazoles and 2H‐diazaphospholes in combination with oxadiazoles, thiadiazoles and triazoles were prepared from phenacylsulfonylacetic acid methyl ester.
Darzens reaction of 2‐bromo‐4,6‐dimethoxy‐3(2H)‐benzofuranone with aromatic aldehydes to form flavonoids
Authors: Ottersbach Philipp A. , Bolek David , Lepičová Eva , Gütschow Michael , Nieger Martin
Published: March 2009

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The applicability of 2‐bromo‐4,6‐dimethoxy‐3(2H)‐benzofuranone (1) to produce flavonoid‐derived epoxides in the course of the Darzens reaction with aldehydes was investigated. However, instead of the epoxides, flavonols 3 and, in certain cases, benzofuranyl‐substituted flavonols 4 were isolated. The generation of 3 is assumed due to a ring expansion of the initially formed epoxides. These flavonols can react with 1 to produce the unexpected 1:2 adducts 4 as minor products. The structure of the hexamethoxy derivative 4b (R1 = H, R2 = R3 = OMe) was confirmed by X‐ray crystallographic analysis.
Synthesis and anti‐HIV‐1 evaluation of 1,5‐disubstituted pyrimidine‐2,4‐diones
Authors: Loksha Yasser M. , Globisch Daniel , Pedersen Erik B. , La Colla Paolo , Collu Gabriella , Loddo Roberta
Published: March 2009

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1,5‐Disubstituted pyrimidine‐2,4‐diones were synthesized by fusion of 5‐bromouracil with an aniline derivative followed by coupling with benzyl halide whereas the opposite synthesis sequence failed. Also 4,6‐dichloro‐N,N,5‐trimethylpyrimidin‐2‐amine was treated with phenols. The products were tested for their activity against HIV‐1.
Facile acidic hydrolysis and displacement reactions of 2‐chloro‐and 2,9‐dichloro‐1,10‐phenanthroline
Authors: Krapcho A. Paul , Sparapani Silvia
Published: March 2009

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Treatment of 2‐chloro‐ or 2,9‐dichloro‐1,10‐phenanthroline with aqueous HBr or aqueous H2SO4 at 120°C yielded 1,10‐phenanthroline‐2(1H)‐one or 1,10‐dihydro‐1,10‐phenanthroline‐2,9‐dione, respectively. The hydrolysis of 2,9‐dichloro‐1,10‐phenanthroline with 37% aqueous HC1 led to the half hydrolyzed amide and the bis‐amide. Under comparable reactions conditions, using aqueous HBr, H2SO4 or HC1, 2‐chloropyridine was found to be hydrolytically stable. On the other hand, 2‐chloro‐ or 2,9‐dichloro‐1,10‐phenanthroline on heating with 57% aqueous HI afforded the HI salts of 2‐iodo‐ or 2,9‐diiodo‐1,10‐phenanthroline, which could be isolated. These salts on treatment with aqueous ammonium hydroxide led to good yields of 2‐iodo‐ and 2, 9‐diiodo‐1,10‐phenanthroline, respectively. Treatment of 2‐chloropyridine with 57% aqueous HI under similar reaction conditions led to 2‐iodopyridine in a 10% conversion.
An efficient and clean one‐pot synthesis of 3,4‐dihydropyrimidine‐2(1H)‐ones catalyzed by tungstate sulfuric acid in solvent‐free conditions
Authors: Nasr‐Esfahani Masoud , Karami Bahador , Montazerozohori Morteza , Abdi Karim
Published: March 2009

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Tungstate sulfuric acid catalyzes the three component condensation reaction of an aromatic aldehyde, urea and a β‐ketoester under solvent‐free conditions to afford the corresponding dihydropyrimidinones in high to excellent yields at room temperature.
Synthesis of some novel 2‐substituted‐N‐aryl‐benzoxazole‐5‐carboxamides using cobalt dipyridine dichloride as a catalyst
Authors: Sarangapani M. , Sridhar D. , Arjun M. , Chari M. Adharvana
Published: March 2009

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An efficient synthesis of some novel 2‐substituted‐N‐aryl‐benzoxazole‐5‐carboxamides from 2‐substituted — 5‐carbomethoxy benzoxazole on treatment with different substituted anilines promoted by cobalt dipyridine dichloride as a catalyst is described. This new approach has the advantage of excellent yields (90%) and short reaction times 1‐2 h.
Highly efficient intramolecular cyclizations of 2′‐hydroxychalcones to 4‐chloro‐2H‐chromenes under vilsmeier conditions
Authors: Li Zhen‐Hua , Zheng Cun , Su Wei‐Ke
Published: March 2009

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Highly efficient intramolecular cyclization and of 2′‐hydroxychalcones to 4‐chloro‐2H‐chromenes under Vilsmeier conditions have been developed. In comparison with the reported methods, studies carried out indicate that Vilsmeier reagent generated in situ from DMF and bis(trichloromethyl) carbonate (BTC) provides excellent chemselectivity, higher yields and avoids the formation of inorganic phosphorus salts.
An efficient and expeditious microwave‐assisted synthesis of quinoxaline derivatives via nucleophilic heteroaromatic substitution
Authors: Cuenca Angela , Pérez Suhey , Yepez Arlene , Paredes Luisar , Montecinos Luisana , Llovera Ligia , Rodríguez César
Published: March 2009

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A series of 2‐substituted quinoxaline derivatives including five novel compounds have been successfully synthesized from 2‐chloroquinoxaline using microwave methodology. The yields of the quinoxalines synthesized through this method, were an improvement over the thermal methods usually employed.
Dichloro dicyano quinone (DDQ) as coupling reagent for high yield synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones
Authors: Shobha D. , Chari M. Adharvana , Sadanandam P. , Mukkanti K.
Published: March 2009

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DDQ catalyzes efficiently the three‐component condensation reaction of aldehyde, β‐ketoester and urea in refluxing acetonitrile to afford the corresponding dihydropyrimidinones. Compared to the classical Biginelli reaction conditions, this new approach consistently has the advantage of excellent yields (80‐92%) and short reaction times 1.5‐2.5 h.
New one‐ pot synthesis of pyrazolo[3,4‐c]pyridazine and isoxazolo‐[5,4‐b]pyridine derivatives from potassium cyanoacetahydroxamate
Authors: El‐Rady Eman A. , Barsy Magda A.
Published: March 2009

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The reaction of potassium cyanoacetohydroxamate 1 with ethyl 2‐aryl‐hydrazono‐3‐oxobutyrates 2 gave the unexpected pyrazolo[3,4‐c]pyridazines 7 and isoxazolo[5,4‐b]pyridines 10 via a one‐pot reaction. A mechanistic proof is suggested to account for the products.
An efficient and green synthesis of 3,3′‐benzylidenebis (4‐hydroxy‐6‐methylpyridin‐2(1H)‐one) derivatives through multi‐component reaction in ionic liquid
Authors: Shi Daqing , Ji Shunjun , Shi Daqing , Ni Sainan , Yang Fang
Published: March 2009

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A series of new 3,3′‐benzylidenebis(4‐hydroxy‐6‐methylpyridin‐2(1H)‐one) derivatives were synthesizedviaa three‐component reaction of an aldehyde, an aniline or ammonium acetate and 6‐methyl‐4‐hydroxypyran‐2‐one in ionic liquid. These heterocyclic compounds produced could be conveniently separated from the reaction mixture without any volatile organic solvents, and the ionic liquid could be readily reused without efficiency loss after simple treatment.