bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and X‐ray study of hexahydro‐ and tetrahydrophospholo‐[2,3‐d]isoxazoles, a new class of heterocycles of potential fungicidal activity
Authors: Machetti Fabrizio , Anichini Beatrice , Cicchi Stefano , Brandi Alberto , Wieczorek Wanda , Pietrusiewicz K. Michal , Gehret Jean‐Claude 
Published: March 2009

AbstractHexahydro‐, 5b‐1 and 6a,f,1 and tetrahydrophospholo[2,3‐d]isoxazoles 8, 9 and 10 were synthesized by 1,3‐dipolar cycloaddition of nitrones 3b‐1 and benzonitrile oxide (4) to 2,3‐dihydro‐1‐phenyl‐1H‐phosphole 1‐oxide (1) and 2,3‐dihydro‐1‐ethoxy‐1H‐phosphole 1‐oxide (2). The structural assignment to the compounds was confirmed by an X‐ray study of two compounds of the series 5a and 5m. The compounds show a good activity as fungicides against Plasmopara viticola on vines and against Botrytis cinerea on apples. Compounds 5a‐d showed weak to moderate activity as herbicides.
Syntheses and transformations of substituted benzazolyl‐ and tetrazolyl(benzotriazol‐1‐yl)methanes
Authors: Katritzky Alan R. , Asian Diana , Shcherbakova Irina V. , Chen Jie , Belyakov Sergei A. 
Published: March 2009

AbstractCondensation reactions of o‐hydroxy‐ and o‐mercaptoanilines, and o‐phenylenediamine with (benzotriazol‐1‐yl)acetic acid result in (1,3‐benzazol‐2‐yl)(benzotriazol‐1‐yl)methanes. Cycloaddition of sodium azide to (benzotriazol‐1‐yl)acetonitrile leads to (1,2,3,4‐tetrazol‐5‐yl)(benzotriazol‐1‐yl)methane. The diazolo‐substituted benzotriazolylmethanes thus obtained were mono‐ and di‐alkylated at the methylene group and the displacement of the benzotriazole group by nucleophiles was investigated.
Photochemically induced reactions of selected ketones with 4‐cyanopyridine in neutral and acidic medium
Authors: Bernardi Rosanna , Caronna Tullio , Morrocchi Sergio , Ursini Maurizio 
Published: March 2009

AbstractThe presence of the 4‐cyanopyridine, in neutral or acidic medium, interferes with the normal behavior of the biradicals obtained by direct excitation of selected ketones, and results in formation of pyridinic derivatives.
3′‐Methylsulfinyl‐3,4′‐diquinolinyl sulfides
Authors: Maślankiewicz Maria J. , Maslankiewicz Andrzej 
Published: March 2009

AbstractReactions of 4‐methoxy‐ or 1,4‐dihydro‐4‐oxo‐3′‐methylthio‐3,4′‐diquinolinyl sulfides 1 and 7 with a nitrating mixture ran as the 3′‐methylthio group 5‐mono‐oxidation followed by C6‐ and C8‐nitration and led to the mixture composed of products 3, 4, 5 and 6 (in the case of substrate 1) or compounds 5 and 6 (for substrate 7). In the reaction with hydrochloric acid 4‐methoxy‐3′‐methylsulfinyl‐3,4′‐diquinolinyl sulfides 3 and 4 could be hydrolysed to 3′‐methylsulfinyl‐4(1H)‐quinolinones 5 or 6 respectively, the methylsulfinyl group remaining unaffected.
Selective acetylation of substituted (E)‐4(1H)‐hydroxyimino‐2,3‐dihydro‐1,8‐naphthyridine
Authors: Ferrarini Pier Luigi , Mori Claudio , Belfiore Stefania 
Published: March 2009

AbstractWe report a selective acetylation of compounds 2 in 1‐, 4‐ or 1,4‐position. The treatment of 2 with acetic anhydride gave the compounds 3 and with acetyl chloride the compounds 4. The 1‐acetyl derivatives were obtained starting from 5 via the oxime derivatives 6, 7 and 8. Tests on phytoiatric antimycotic activity and on reactivation of phosphylated acetylcholinesterase and inhibition of acetylcholinesterase were performed.
The synthesis and biological activity of two analogs of the anti‐HIV alkaloid michellamine B
Authors: Upender Velaparthi , Pollart Daniel J. , Liu Jyanwei , Hobbs Peter D. , Olsen Cris , Chao Wan‐Ru , Bowden Bonnie , Crase Jac L. , Thomas David W. , Pandey Anjali , Lawson John A. , Dawson Marcia I. 
Published: March 2009

AbstractTwo simplified analogs of the dimeric naphthalenyltetrahydroisoquinoline alkaloid michellamine B [4′,4″‐didesmethoxy‐2′,2″‐didesmethylmichellamine B and 6,8‐dihydroxy‐5‐(1′,1″‐dihydroxy‐2′,2″‐binaphthalen‐4′‐yl)‐1R,3R‐dimethyl‐1,2,3,4‐tetrahydroisoquinoline] were synthesized using Suzuki palladiumcatalyzed biaryl cross‐coupling of 4‐(2‐benzyl‐6,8‐dibenzyloxy‐1R,3R‐dimethyl‐1,2,3,4‐tetrahydroisoquinolin‐5‐yl)‐1‐benzyloxy‐2‐bromonaphthalene to its corresponding atropisomeric 2‐naphthaleneboronic acid and 1‐benzyloxy‐2‐naphthaleneboronic acid, respectively. These analogs inhibited recombinant HIV reverse transcriptase with IC5() values of 62 μM and 1000 μM, respectively, whereas the IC5() value for michellamine B was 33 μM. Both michellamine B and the analogs inhibited the phosphorylation of histories by rat brain protein kinase C. The analogs were more active (IC50 values of 36 μM and 30 μM, respectively) than michellamine B (IC50 = 130 μM).
Reactions of 1,2,4‐triazines with nitromethide ion. A convenient method of preparation of 1,2,4‐triazin‐5‐ylcarbaldehyde oximes and their synthetic applications
Authors: Rykowski Andrzej , Branowska Danuta , Makosza Mieczyslaw , Van Ly Phan 
Published: March 2009

AbstractAn efficient procedure for the preparation of 1,2,4‐triazin‐5‐ylcarbaldehyde oximes 2a‐f from 1,2,4‐triazines 1a‐f and nitromethide ion is described. The oximes 2c‐d were converted into corresponding 5‐cyano‐1,2,4‐triazines 6c‐d. The latter compounds react easily with various nucleophiles to afford 5‐substituted 1,2,4‐triazines 7a‐i and with 1‐pyrrolidino‐1‐cyclohexene to form cyano derivative of 5,6,7,8‐tetrahydroisoquinoline 9.
Synthesis of substituted pyrrolo[2,3‐e][1,3,4]thiadiazine 4,4‐dioxides
Authors: Stephens Chad E. , Sowell J. Walter 
Published: March 2009

AbstractA series of substituted pyrrolo[2,3‐e][1,3,4]thiadiazine 4,4‐dioxides is synthesized from 1‐substituted‐2‐amino‐3‐cyanomethylsulfonyl‐4,5‐dimethylpyrroles.
1,3‐Dipolar cycloadditions of electron‐rich benzotriazol‐1‐ylpropenes
Authors: Katritzky Alan R. , Musgrave Richard R. , Breytenbach Jaco C. 
Published: March 2009

AbstractThe preparation of trans‐3‐benzotriazol‐1‐yl‐1‐(N‐rnorpholino)prop‐1‐ene (1), trans‐3‐benzotriazol‐1‐yl‐1‐ethoxyprop‐1‐ene (2) and trans‐1,3‐bis‐(benzotriazol‐1‐yl)propene (3) and their reactions with a benzonitrile oxide (4), N‐(2,4‐dibromophenyl)‐1‐phenylnitrilimine (5), and p‐nitrophenyl azide (6) are described.
Synthesis of 1H‐pyrazino[1,2‐a]pyrido[2,3‐e]pyrazine and 2H‐Pyrano[2,3‐b]pyrido[2,3‐e]pyrazine Derivatives
Authors: Savelli Francesco , Boido Alessandro , Damonte Gianluca 
Published: March 2009

AbstractWith a continuing interest on heteropolycyclic structures which may show biological activities, we synthesized new tricyclic derivatives in which the pyridopyrazine skeleton is fused with pyrazine 7 and 8, B, n = 1. However, the initial design of obtaining also the cyclohomologous structure B (n = 2) produced instead a pyranopyridopyrazine derivative 11. Thus during the attempt to prepare a pyridodiazepine intermediate, beside a very small amount of the desired product 10, the pyridopyrazine 9 was obtained. The latter compound reacted with chloroacetyl chloride/chloroketene to give 4‐carbethoxy‐10‐(chloroacetyl)‐5,10‐dihydro‐5‐methyl‐2H‐pyrano[2,3‐b]pyrido[2,3‐e]pyrazin‐2‐one (11). In studying the behavior of this derivative, compounds 12–14 were obtained. Compounds 4b,c, 5a,b, 7, 8, 9 and 14 have been submitted to preliminary pharmacological screening as CNS depressant agents.
A new method for the synthesis of 4H‐1,3,4‐thiadiazino[5,6‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Sekine Masae , Kim Ho Sik , Okamoto Yoshihisa 
Published: March 2009

AbstractThe reaction of 6‐chloro‐2‐[1‐methyl‐2‐(Mmemylthiocarbamoyl)hydrazino]quinoxaline 4‐oxide 5 with acetic anhydride or trifluoroacetic anhydride resulted in dehydrative cyclization to give 2‐(N‐acetyl)‐memylamino‐8‐chloro‐4‐methyl‐4H‐1,3,4‐thiadiazino[5,6‐b]quinoxaline 6 or 8‐chloro‐2‐(N‐trifluoroacetyl)methylamino‐4‐methyl‐4H‐1,3,4‐thiadiazino[5,6‐b]quinoxaline 9, respectively. The oxidation of compound 6 or 9 with 2‐fold molar amount of m‐chloroperbenzoic acid afforded the 4H‐1,3,4‐thiadiazino‐[5,6‐b]quinoxaline 1,1‐dioxide 8 or 13, respectively. The acetyl group of compound 6 was hardly hydrolyzed, but the trifluoroacetyl group of compound 9 was easily hydrolyzed to change into 8‐chloro‐4‐methyl‐2‐memylamino‐4H‐1,3,4‐thiadiazino[5,6‐b]quinoxaline 10. The acylation of compound 10 with acetic anhydride, trifluoroacetic anhydride, phenyl isocyanate, and chloroacetyl chloride furnished the 2‐(N‐acetyl)methylamino 6, 2‐(N‐trifluoroacetyl)methylamino 9, 2‐(1‐methyl‐3‐phenylureido) 11, and 2‐(N‐chloroacetyl)methylamino 12 derivatives, respectively.
A new synthetic route to 7H‐imidazo[1,2‐b][1,2,4]triazoles
Authors: Lee Kee‐Jung , Song Dong‐Hyuk , Kim Dong‐Jin , Park Sang‐Woo 
Published: March 2009

AbstractThe reaction of benzil 1‐ureidoethylidenehydrazones 8 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine provides a general route to 7H‐imidazo[1,2‐b][1,2,4]triazoles 18 via the thermal reaction of the expected ketoazine carbodiimide intermediates 13, and the structure of 18 was confirmed by X‐ray crystallographic analysis.
Syntheses of 5‐hydroxy‐2‐(phenyl or styryl)chromones and of some halo derivatives
Authors: Pinto Diana C. G. A. , Silva Artur M. S. , Cavaleiro José A. S. 
Published: March 2009

AbstractOne‐pot syntheses of 5‐hydroxy‐2‐(phenyl or styryl)chromones and the corresponding 6‐ and 8‐monoiodo‐ and 6,8‐diiodochromones have been developed. The procedures involve oxidative cyclization of 2′‐benzyloxy‐6′‐hydroxychalcones and 2′‐benzyloxy‐6′‐hydroxy‐2‐cinnamylideneacetophenones and electrophilic substitution processes on the chromone moieties; such procedures were also applied to the syntheses of 6,8‐dibromochromone derivatives.
Brominated trimetrexate analogues as inhibitors of pneumocystis carinii and toxoplasma gondii dihydrofolate reductase
Authors: Rosowsky Andre , Mota Clara E. , Queener Sherry E. 
Published: March 2009

AbstractFive previously undescribed trimetrexate analogues with bulky 2′‐bromo substitution on the phenyl ring were synthesized in order to assess the effect of this structure modification on dihydrofolate reductase inhibition. Condensation of 2‐[2‐(2‐bromo‐3,4,5‐trimethoxyphenyl)ethyl]‐1,l‐dicyanopropene with sulfur in the presence of N,N‐diethylamine afforded 2‐amino‐5‐(2′‐bromo‐3′,4′,5′‐trimethoxybenzyl)‐4‐methyl‐thiophene‐3‐carbonitrile (15) and 2‐amino‐4‐[2‐(2′‐bromo‐3′,4′,5′‐trimethoxyphenyl)ethyl]thiophene‐3‐car‐bonitrile (16). Further reaction with chloroformamidine hydrochloride converted 15 and 16 into 2,4‐diamino‐5‐(2′‐bromo‐3′,4′,5′‐trimethoxybenzyl)‐4‐methylthieno[2,3‐d]pyrimidine (8a) and 2,4‐diamino‐4‐[2‐(2′‐bromo‐3′,4′,5′‐trimethoxyphenyl)ethylthieno[2,3‐d]pyrimidine (12) respectively. Other analogues, obtained by reductive coupling of the appropriate 2,4‐diaminoquinazoline‐6(or 5)‐carbonitriles with 2‐bromo‐3,4,5‐trimethoxyaniline, were 2,4‐diamino‐6‐(2′‐bromo‐3′,4′,5′‐trimethoxyanilinomethyl)‐5‐chloro‐quinazoline (9a), 2,4‐diamino‐5‐(2′‐bromo‐3′,4′,5′‐trimethoxyanilinomethyl)quinazoline (10), and 2,4‐diamino‐6‐(2′‐bromo‐3′,4′,5′‐trimethoxyanilinomethyl)quinazoline (11). Enzyme inhibition assays revealed that space‐filling 2′‐bromo substitution in this limited series of dicyclic 2,4‐diaminopyrimidines with a 3′,4′,5′‐trimethoxyphenyl side chain and a CH2, CH2CH2, or CH2NH bridge failed to improve species selectivity against either P. carinii or T. gondii dihydrofolate reductase relative to rat liver dihydrofolate reductase.
Complete assignment of the 1H and 13C NMR spectra of 4‐methoxy‐3′‐methylsulfinyl‐3,4′‐diquinolinyl sulfides
Authors: Maślankiewicz Maria J. , Maślankiewicz Andrzej 
Published: March 2009

AbstractThe 1H and 13C nmr spectra of 4‐methoxy‐3′‐methylsulfinyl‐3,4′‐diquinolinyl sulfides 2, 3 and 4 were totally assigned using a combination of nmr techniques. As compared to the spectral data of sulfoxide 2 typical values of nitro group substituents effects in nitroquinolines 3 and 4 were observed. The H‐2′ protons in sulfoxides 2, 3 and 4 are strongly influenced by ortho methylsulfinyl group and deshielded by about 0.7 ppm. PM3 method calculations support the structural conclusion that sulfinyl group oxygen points in direction of the positions 2′.
Research on photochemical and thermochemical reactions between indole and quinones in the absence of solvent
Authors: Wang Yong‐Mei , Wen Zhong , Chen Xiao‐Min , Du Da‐Ming , Matsuura Teruo , Meng Ji‐Ben 
Published: March 2009

AbstractThe solid state photochemical reaction of indole with 1,4‐naphthoquinone yielded 5H‐dinaphtho[2,3‐a:‐2′,3′‐c]carbazole‐6,11,12,17‐tetrone (1) in addition to 2‐(3‐indolyl)‐1,4‐naphthoquinone (2) which was also the only product in the solution photoreaction. Solventless thermochemical reactions of indole with phenanthrenequinone in the presence or absence of zinc chloride gave 10‐(1H‐indol‐3‐yl)‐9‐phenanfhrenol (3) and 9,10‐dihydro‐9‐(1H‐indol‐3‐yl)‐10‐(3H‐indol‐3‐ylidene)‐9‐phenanthrenol (4) or 10,10‐di‐1H‐indol‐3‐yl‐9(10H)‐phenanthrenone (5), respectively. All of these products were only obtained in trace amount in corresponding solution reactions, and are different from the adduct 10‐hydroxy‐10‐(1H‐indol‐3‐yl)‐9(10H)‐phenanthrenone (6) obtained in the solution photoreaction. A possible mechanism for formation of 4 and 5 is described in terms of electron pair donor/acceptor complexation.
Synthesis of symmetrical 2,2′,4,4′‐tetrasubstituted[4,4′‐bioxazole]‐5,5′(4H,4′H)‐diones and their reactions with some nucleophiles
Authors: Andersen Kenneth K. , Gloster Daniel F. , Bray Diana D. , Shoja Massud , Kjær Anders 
Published: March 2009

AbstractSeveral symmetrical 2,2′,4,4′‐tetrasubstituted[4,4′‐bioxazole]‐5,5′(4H,4′H)‐diones 1a‐f were obtained by dehydrodimerization of 5(4H)‐oxazolones 2a‐f. The configurations of four were established; one by X‐ray crystallography rac‐1c, and three rac‐1a, meso‐1a and rac‐1b by 1H nmr spectroscopy of their derivatives. Upon being heated, the bioxazolones isomerized, presumably by breakage of the 4,4′‐carboncarbon bond to form free radicals followed by their recombination. The results of a crossover experiment were consistent with a radical nature for this isomerization reaction. Treatment of three of the bioxazolones rac‐1a, meso‐1a and rac‐1c with methanol and amine nucleophiles led to ester and amide derivatives 7–11 of α,α'‐dehydrodimeric amino acids.
Metalation of t‐butyl sulfoxides, sulfones and sulfonamides of pyridazine and pyrazine. Metalation of diazines. XX
Authors: Turck Alain , Plé Nelly , Pollet Paméla , Quéguiner Guy 
Published: March 2009

AbstractIn the pyridazine series, the use of tert‐butylsulfinyl and tert‐butylsulfonyl as ortho directing groups for metalation has been tested. Various functionalized products were obtained in good yields. In the case of 3‐tert‐butylsulfinyl‐6‐methoxypyridazine, the metalation was regioselective in ortho to the sulfinyl group. The metalation of 2‐tert‐butylsulfinyl and 2‐tert‐butylsulfonylpyrazine gave low to moderate yields. Synthesis of diazinesulfonamides were improved and the metalation of N‐tert‐butylsulfonamidopyrazine was achieved.
Synthesis of (±)‐methylenolactocin and (±)‐trans cognac lactone
Authors: Ohta Yasuo , Okamoto Takashi , Tamura Masumi , Doe Matsumi , Morimoto Yoshiki , Kinoshita Takamasa , Yoshihara Kazuo 
Published: March 2009

AbstractThe title compounds were efficeintly synthesized from 3‐fuancarboxylic acid via the Birch recuction‐elimination.
Studies on pyrrolidinones. Synthesis of 1‐[(N‐acetylarylamino)methyl]pyroglutamic acid derivatives
Authors: Ghammarti Samira El , Rigo Benoit , Mejdi Hechmi , Hénichart Jean‐Pierre , Couturier Daniel 
Published: March 2009

AbstractPyroglutamic acid was transformed into 1‐[(N‐Acetylarylamino)methyl]pyroglutamic acid derivatives by using trimethylsilyl variations of the Mannich reaction.
Some aspects of reduced quinoline chemistry
Authors: Kouznetsov Vladimir , Palma Alirio , Ewert Claude , Varlamov Alexei 
Published: March 2009

AbstractDifferent synthetic paths that produce the reduced quinoline cycle are discussed: among them intramolecular cyclization, intra‐ and inter [4+2] cycloaddition reactions and other methods. Some chemical properties of tetrahydroquinolines are also analyzed.
Regioselective epoxide ring opening. Steroselective synthesis of a tetrahydropyran ring
Authors: Gruttadauria Michelangelo , Noto Renato , Riela Serena 
Published: March 2009

AbstractThe stereoselective synthesis of a 2‐substituted tetrahydropyran with adjacent alkoxy‐bearing stereogenic centre is described. The key steps of this synthesis were the stereoselective epoxidation of an allylic alcohol and the regioselective epoxide ring opening by lithium aluminum hydride. The regio and stereoselective synthesis of a trihydroxyselenide and a trihydroxysulfide is also described. The latter compounds are not suitable for cyclization to tetrahydrofuran ring.
An efficient approach to N‐protected 1,2,3,3a‐tetrahydrocyclopenta[b]quinolin‐1‐ones
Authors: Kratzel Martin , Mabhoti Reza 
Published: March 2009

AbstractIn the course of our investigations into the synthesis of benzoanalogues of streptazolin we also studied the construction of 1,2,3,3a‐tetrahydrocyclopenta[b]quinolin‐1‐ones which could be successfully solved by an intramolecular acylation using a bromo‐lithium exchange, starting from 3‐bromoquinoline.
Boron‐containing nucleosides. 1. Synthesis of the novel heterocycle 2‐benzyl‐1,4‐dihydro‐1‐hydroxythieno[3,2‐c][1,5,2]diazaborin‐3(2H)‐one: A thieno‐fused 4‐borauracil
Authors: Graham Steven M. , Ohrtman Loralee M. 
Published: March 2009

AbstractThe synthesis of the novel boron‐containing nucleobase 2‐benzyl‐1,4‐dihydro‐1‐hydroxythieno[3,2‐c]‐[1,5,2]diazaborin‐3(2H)‐one (8), a thieno‐fused 4‐borauracil, is described. Compound 8 was prepared in three steps starting from 2‐thiophenecarbonyl chloride (4). A multinuclear and multisolvent nmr study of 8 indicates that the boron atom maintains a trigonal geometry in the solvents used.
Synthesis of 5‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,7]naphthyridines and 2,3,4,4a,5,6‐hexahydrobenzo[c][2,6]naphthyridines
Authors: Giudice Maria Rosaria Del , Mustazza Carlo , Ferretti Rosella , Borioni Anna , Gatta Franco 
Published: March 2009

AbstractThis paper describes the synthesis of some 5‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,7]naphthyridines and 2,3,4,4a,5,6‐hexahydrobenzo[c][2,6] naphthyridines starting from anilines and 1‐benzyl‐4‐ethoxycarbonylpiperidin‐3‐one. The compounds were prepared in order to study their potential acetylcholinesterase inhibitory activity.
Electrochemical properties of pyrido[1′,2′:1,2]imidazo[4,5‐b]pyrazine and pyrido[1′,2′:1,2]imidazo[4,5‐b]quinoxaline derivatives
Authors: Iwata Satoru , Tanaka Kiyoshi 
Published: March 2009

AbstractThe peak potentials (Ep) of 3‐substituted pyrido[1′,2′:1,2]imidazo[4,5‐b]pyrazine and pyrido[1′,2′:1,2]‐imidazo[4,5‐b]quinoxaline derivatives are sufficiently correlated with Hammett substituent constant ∼m and with the PM3 calculated LUMO energy levels, and the linear relationship between electron potentials of 9‐substituted pyridoimidazoquinoxalines and the LUMO energy levels is also found out.
Purines XIV.. Reactivity of 8‐bromo‐3,9‐dimethylxanthine towards some nucleophilic reagents
Authors: Youssef Shaker , Pfleiderer Wolfgang 
Published: March 2009

AbstractThe reactivity of 8‐bromo‐3,9‐dimethylxanthine (6) towards a variety of nucleophilic reagents has been investigated. Nucleophilic displacements take place easily with aliphatic mercaptans and aliphatic alcohols, whereas aliphatic amines required more severe conditions. Prolonged heating of 6 with amines causes a new type of rearrangement from 3,9‐ to 3,7‐dimethylxanthines due to a 1,3‐sigmatropic shift of the N(9)‐methyl group.
Synthesis of 2‐(p‐R‐benzoylmethylene)‐3‐(p‐R‐phenyl)‐1H‐quinoxalines
Authors: Insuasty Braulio , Fernéandez Fernando , Quiroga Jairo , Moreno Rodolfo , Martinez Roberto , Angeles Enrique , Gaviñto Rubéan , De Almeida Regina H. S. 
Published: March 2009

AbstractThe reaction of 1,2‐diaminobenzenes with substituted 1,2‐dibenzoyl‐1,2‐dibromoethanes constitutes a convenient synthetic route to the hitherto 2‐(p‐R‐benzoylmethylene)‐3‐(p‐R‐phenyl)‐1H‐quinoxalines. Structures of all products were elucidated by ir, 1H and 13C‐nmr, mass spectra data. X‐Ray crystallography data confirm assigned structures.
Imidazo[1,2‐b]pyridazines: Syntheses and interaction with central and peripheral‐type (mitochondrial) benzodiazepine receptors
Authors: Barlin Gordon B. 
Published: March 2009

AbstractThe fundamental chemistry of pyridazines, the syntheses of substituted irnidazo[1,2‐b]pyridazines (1) (and some related compounds) and the interaction of the products with central benzodiazepine receptors (CBR) and peripheral‐type (mitochondrial) benzodiazepine receptors (PBR) are described.Some of these imidazo[1,2‐b]pyridazines had high selective affinity for the central benzodiazepine receptors and others had high selectivity for the peripheral‐type (mitochondrial) benzodiazepine receptors. The results of structure‐activity studies and molecular modeling will be reported.In vivotests of some compounds which interacted strongly with the central benzodiazepine receptors revealed reasonably potent anticonvulsant/anticonflict activity, and some of those which bind selectively to the peripheral‐type (mitochondrial) benzodiazepine receptors are being examined as possible radiopharmaceuticals for imaging of tumors (and other disease states).
Furopyridines. XXVI. Reactions of cyanopyridine derivatives of furo[2,3‐b]‐, ‐[3,2‐b]‐, ‐[2,3‐c]‐ and ‐[3,2‐c]pyridine
Authors: Yamaguchi Sciji , Saitoh Hideo , Kurosaki Masahide , Yokoyama Hajime , Hirai Yoshiro , Shiotani Shunsaku 
Published: March 2009

AbstractBromination of α‐cyanopyridine derivatives of furopyridines 1a‐d gave the 2,3‐dibromo‐2,3‐dihydro compounds 2a‐d in excellent yields. Treatment of 2a‐d with sodium hydroxide in methanol yielded compounds formed through the dehydrobromination and solvolysis of the nitrile. N‐Oxidation of 1a and 1b gave N‐oxide in much poor yield, while 1c and 1d gave the N‐oxide 13c and 13d in good yields. The nucleophilic reactions (cyanation, chlorination and acetoxylatoin) of 13c through a Reissert‐Henze type reaction gave poor results, which would be caused by the strong electron withdrawing effect of the cyano group.
Furopyridines. XXIX. Reactions of furo[2,3‐b:4,5‐c‘]‐, ‐[3,2‐b:‐4,5‐c’]‐, ‐[2,3‐c:4,5‐c‘]‐ and ‐[3,2‐c:3,2‐c’]dipyridine
Authors: Yamaguchi Seiji , Orito Keiko , Shimizu Noriko , Taniguchi Katsunori , Saitoh Hideo , Kurosaki Masahide , Yokoyama Hajime , Hirai Yoshiro , Shiotani Shunsaku 
Published: March 2009

AbstractFuro[2,3‐b:4,5‐c‘]‐ 1a, ‐[3,2‐b:4,5‐c’]‐ 1b, ‐[2,3‐c:4,5‐c‘]‐ 1c and ‐[3,2‐c:4,5‐c’]dipyridine 1d were derived to the N‐oxides 2a‐d, N‘‐oxides 2′b, 2′c or N,N’‐dioxide 3b‐d by N‐oxidation with m‐chloroperbenzoic acid. Chlorination of these N‐oxides, N′‐oxide and N,N′‐dioxides with phosphorus oxychloride afforded compounds chlorinated at the α‐position(s) to the ring nitrogen 4a‐d, 4′c, 14b‐d and 14′b. Acetoxylation of N‐oxides 2a‐d and 2′c with acetic anhydride gave the corresponding pyridone compounds 6a‐d and 6′c in good yields, while the acetoxylation of N,N′‐dioxides gave a complex mixture from which no compound could be isolated. Cyanation of 2a‐d, 2′c and 3b‐d with trimethylsilyl cyanide yielded the cyano compounds 7a‐d, 7′c, cyano‐N‐oxides 15b‐d and dicyano compounds 15′c and 15′d. Monocyano compounds 7a‐d and 7′c were converted to the imino esters 8a‐d and 8′c by treatment with sodium ethoxide. Imino esters were derived to the carboxylic esters 9a‐d and 9′c, from which the corresponding alde hydes 10a‐d and 10′c were obtained by reduction with diisobutylaluminum hydride. Dicyanide 15′c was converted to dialdehyde 19 by the treatment with sodium ethoxide, and the subsequent hydrolysis of the imino ester and reduction of the carboxylic ester with diisobutylaluminum hydride.
2‐aminothiophenes by the gewald reaction
Authors: Sabnis R. W. , Rangnekar D. W. , Sonawane N. D. 
Published: March 2009

AbstractThe review presents the most elegant and promising set of synthetic routes for the synthesis of 2‐aminothiophenes by the Gewald reaction. Applications of this facile methodology to pharmaceuticals and dyestuffs have been demonstrated.