bluuebunny/crossref_metadata_2025_split huggingface dataset:
Apples and oranges? Corporate rescue and functional convergence in the US and UK
Authors: McCormack Gerard 
Published: May 2009

AbstractThis paper challenges the standard characterisation that US law in the sphere of corporate bankruptcy is ‘pro debtor’ and UK law is ‘pro creditor’. It suggests that the traditional thesis is, at best, a potentially misleading over‐simplification. It also offers the conclusion that there is functional convergence in practice, while acknowledging that corporate rescue, as distinct from business rescue, still plays a larger role in the US. The functional convergence has partly come through the UK Enterprise Act 2002 but the paper suggests that the main move has been that of US law and practice in a UK direction with more emphasis on business disposals and speedier cases than on corporate reorganisations, as traditionally understood. This mirrors practice in the UK where the emphasis has always been on business disposals. Unfortunately, the current economic recession on both sides of the Atlantic has shone a heightened spotlight on business bankruptcy and is likely to generate further changes in practice and ultimately legislation. Copyright © 2009 John Wiley & Sons, Ltd.
Ab initio and DFT studies of the thermal rearrangement of trimethylsilyl(methyl)silylene: Remarkable rearrangements of silicon intermediates
Authors: Boo Bong Hyun , Im Suk , Lee Sungyul 
Published: May 2009

AbstractA reaction scheme for the rearrangement of trimethylsilyl(methyl)silylene (Me3Si–S̈i–Me) discovered in a pioneering work of organosilicon chemistry (Wulff et al., J Am Chem Soc 1978, 100, 6236) was studied by the MP2 and DFT methods. We report a thermal reaction scheme for the rearrangement of Me3Si–
$\ddot{{\rm Si}}$–Me with the structures and energies of various silicon species along the isomerization paths, that can account for the experimentally found product ratio. The experimental product ratio is in good agreement with the theoretical one derived from the Gibbs free energy changes calculated in the present study. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010
Prediction of membrane spanning segments and topology in β‐barrel membrane proteins at better accuracy
Authors: Ou Yu‐yen , Chen Shu‐an , Gromiha M. Michael 
Published: May 2009

AbstractPrediction of membrane spanning segments in β‐barrel outer membrane proteins (OMP) and their topology is an important problem in structural and functional genomics. In this work, we propose a method based on radial basis networks for predicting the number of β‐strands in OMPs and identifying their membrane spanning segments. Our method showed a leave‐one‐out cross validation accuracy of 96% in a set of 28 OMPs, which have the range of 8–22 β‐strand segments. The β‐strand segments in OMPs and the residues in membrane spanning segments are correctly predicted with the accuracy of 96% and 87%, respectively. We have developed a web server, TMBETAPRED‐RBF for predicting the transmembrane β‐strands from amino acid sequence and it is available at http://rbf.bioinfo.tw/∼sachen/tmrbf.html. We suggest that our method could be an effective tool for predicting the membrane spanning regions and topology of β‐barrel membrane proteins. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010
Using multistate free energy techniques to improve the efficiency of replica exchange accelerated molecular dynamics
Authors: Fajer Mikolai , Swift Robert V. , McCammon J. Andrew 
Published: May 2009

AbstractReplica exchange accelerated molecular dynamics (REXAMD) is a method that enhances conformational sampling while retaining at least one replica on the original potential, thus avoiding the statistical problems of exponential reweighting. In this article, we study three methods that can combine the data from the accelerated replicas to enhance the estimate of properties on the original potential: weighted histogram analysis method (WHAM), pairwise multistate Bennett acceptance ratio (PBAR), and multistate Bennett acceptance ratio (MBAR). We show that the method that makes the most efficient use of equilibrium data from REXAMD simulations is the MBAR method. This observation holds for both alchemical free energy and structural observable prediction. The combination of REXAMD and MBAR should allow for more efficient scaling of the REXAMD method to larger biopolymer systems. © 2009 Wiley Periodicals, Inc. J Comput Chem 2009
Syntheses of benzo[b]‐ and benzo[j]phenanthridines
Authors: Klemm L. H. , Weisert Annekäte 
Published: May 2009

AbstractThe isomeric lactams benzo[b]phenanthridine‐5(6H)‐one and benzo[j]phenanthridine‐6(5H)‐one were obtained in equal yields by Schmidt reaction on 11H‐benzo[b]fluoren‐11‐one (44% total) or by Beckmann reaction on 11H‐benzo[b]fluoren‐11‐one oxime (22% total). Reduction of the lactams with lithium aluminum hydride gave the 5, 6‐dihydro‐benzo[b]‐ and ‐[j]phenanthridines. Dehydrogenation of these dihydro derivatives produced the parent aromatic heterocycles benzo[b]‐ and benzo[j]phenanthridine in best overall yields of 20% and 12%, respectively. A few substituted benzophenanthridines were also prepared. Assignment of structures was based on ultraviolet, infrared, and n.m.r. spectra of the dihydro derivatives as well as on separate unequivocal synthesis of the isomeric benzophenanthridines.
Analogs of tetrahydrofolic acid. XXXI. Hydrophobic bonding to dihydrofolic reductase. III. Further observations on conformational aspects of hydrophobic bonding with some 5‐alkyl‐2,4‐diamino‐6‐pyrimidinols
Authors: Baker B. R. , Lourens Gerhardus J. 
Published: May 2009

AbstractThirteen 5‐alkyl ‐ 2, 4 ‐diamino ‐ 6 ‐ pyrimidinols have been compared as inhibitors of dihydrofolic reductase in an attempt to delineate some of the conformational requirements for hydrophobic bonding to the enzyme; definite conformational limitations were observed. For example, cyclohexyl and trans‐crotyl side‐chains gave inhibitors that were as effective as the n‐butyl‐6‐pyrimidinol, whereas, isoamyl was better than all three; these results indicate that the n‐butyl group complexes in a near‐staggered conformation and additional hydrophobic bonding can be obtained by branching at C3 of the butyl group. Methyl branching at C2 of the n‐butyl group also gave a better inhibitor than n‐butyl, but the 2‐methylbutyl side‐chain was only half as effective as isoamyl; in contrast, the 1‐methylbutyl side‐chain gave an inhibitor only one‐half as effective as n‐butyl. That the amount of hydrophobic bonding was simply an “extraction process” dependent upon the size of the hydrocarbon group was unequivocally eliminated.
On 1,2‐benzisoxazole‐3‐acetic acid
Authors: Casini Giovanni , Gualtieri Fulvio , Stein Maria Luisa 
Published: May 2009

AbstractThe proposed 6‐ and 7‐methyl‐1,2‐benzisoxazole‐3‐acetic acids (3) have been shown to be 6‐ and 7‐methyl‐4‐hydroxyimino‐2‐oxo‐chromans. The method of preparation of these unknown acids was demonstrated by the synthesis of 1,2‐benzisoxazole‐3‐acetic acid, starting from 3‐methyl‐1,2‐benzisoxazole. Comparative results of the auxin test are reported.
Ten‐π‐electron nitrogen heterocyclic compounds VI: NMR spectra, HMO calculations and bromination of some diazaindenes
Authors: Paudler William W. , Dunham David E. 
Published: May 2009

AbstractThe bromination of pyrrolo[1, 2‐a]pyrazine and of pyrrazolo[1, 2‐a]pyridine yields the 1,3‐dibromo and 1‐bromo derivatives, respectively. These results are in agreement with the predictions based on frontier‐electron density calculations. The nmr spectra of the compounds prepared in this study are analyzed in detail.
2,6‐Dialkylpiperazines. III. NMR spectra of the geometrical isomers of 4‐phenyl‐2,6‐dimethylpiperazine
Authors: Gallo Gian Gualberto , Vigevani Aristide 
Published: May 2009

AbstractThe cis and trans configurations of the two geometrical isomers of 4‐phenyl‐2,6‐dimethylpiperazine are assigned by NMR spectroscopy.
Pyrrolo[2,3‐d] pyrimidines. I. 5‐hydroxypyrrolo[2,3‐d] pyrimidines
Authors: Kim Dong Han , Santilli Arthur A. 
Published: May 2009

Abstract5‐Hydroxy‐7‐alkyl‐2‐phenyl‐7H‐pyrrolo[2,3‐d]pyrimidine‐6‐carbonitriles (VIIb‐d) and 5‐hydroxy‐2‐phenyl‐7H‐pyrrolo[2,3‐d]pyrimidine‐6‐carboxylic acid, ethyl ester (VIIa) were prepared from 5‐carbethoxy‐4‐chloro‐2‐phenylpyrimidine (IV) via 4‐[(cyanomethyl)alkylamino[‐2‐phenyl‐5‐pyrimidinecarboxylic acid, ethyl esters (Vb‐d) and 4‐[(carboxymethyl)amino]‐2‐phenyl‐5‐pyrimidinecarboxylic acid, diethyl ester (Va), respectively. The hydroxy group of the pyrrolo‐[2,3‐d]pyrimidines could be methylated, acetylated and tosylated. Hydrolysis of 5‐methoxy‐7‐methyl‐2‐phenyl‐7H‐pyrrolo[2,3‐d]pyrimidine‐6‐carbonitrile (IX) afforded the corresponding amide (X).
Preparation of halomethyl‐1,3,4‐thiadiazoles. Conversion to 2‐amino‐5‐(1‐methyl‐5‐nitro‐2‐imidazolyl)‐1,3,4‐thiadiazole, an important antimicrobial agent
Authors: Remers William A. , Gibs Gabriel J. , Weiss Martin J. 
Published: May 2009

AbstractA new route for the synthesis of 2‐amino‐5‐(l‐methyl‐5‐nitro‐2‐imidazolyl)‐1,3,4‐thiadiazole (1) is described. This route was based upon the preparation of 2‐amino‐5‐halomethyl‐1,3,4‐thiadiazoles by condensation of haloacetic acids with thiosemicarbazide. One of these intermediates, 2‐acetamido‐5‐dichloromethyl‐1,3,4‐thiadiazole (4), was hydrolyzed to the corresponding 5‐amino‐2‐carboxaldehyde 6, which was trapped as its oxime 5. 5‐Acetamido‐1,3,4‐thiadiazole‐2‐carbonitrile (7), formed upon dehydration of 5, was then converted into 2‐amino‐5‐(2‐imidazolyl)‐1,3,4‐thiadiazole (11) by a route based on the Pinner amidine synthesis. Methylation and nitration of the imidazole moiety then completed the preparation of 1.
The azomethine nitrene. II. Photolysis of 3‐phenyl‐ Δ2 ‐oxadiazol‐5‐one
Authors: Boyer J. H. , Frints P. J. A. 
Published: May 2009

AbstractIrradiation at 2537 Å eliminates carbon dioxide from 3‐phenyl‐ Δ2‐oxadiazol‐5‐one in either methanol or dioxane. A migration of phenyl from carbon to nitrogen leads to phenylcarbodiimide (8) which tautomerizes into phenylcyanamide (10). Benzamidine (11) and the 0‐methyl ether (12) of benzamidoxime apparently result from hydrogen abstraction and insertion reactions of an intermediate unrearranged azomethine nitrene (9). More extensive fragmentation produces benzonitrile (7), which is isolated, and presumably phenylcarbene (20) to account for benzyl methyl ether (15). Generation of the carbene is discussed. The formation of 3,5‐diphenyltriazole (6), triphenyltriazine (16) and N‐cyanobenzamidine (15) remains unexplained.
Benzo[b] thiophene derivatives. XIV. Derivatives of naphtho[1,8‐c] thiophene
Authors: Campaigne K. , Knapp D. R. 
Published: May 2009

AbstractIn the course of our efforts to synthesize the sulfur isostere of lysergic acid, we have prepared a number of derivatives of the little known naphtho[1,8‐bc]thiophene ring system. Two previously reported compounds, 2‐bromo‐3,4‐dihydro‐5‐oxo‐5H‐naphtho[1,8‐bc]thiophene and 2‐bromo‐5‐hydroxy‐3,4‐dihydro‐5H‐naphtho[1,8‐bc] thiophene have been obtained pure for the first time, and the syntheses and spectral data of eighteen new compounds are presented. The new compounds include alcohols, ketones, and halogen derivatives of partially reduced naphtho‐[1,8‐bc] thiophene, as well as the sulfones of several of these compounds.
Reaction of 2‐aminobenzamide analogs and 2‐aminothiophenol with ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate. Synthesis of pyrrolo[1,2‐α]quinazoline and pyrrolo[1,2‐a]benzothiazoline derivatives
Authors: Kurihara Takushi , Tani Tsutomu , Maeyama Sigeru , Sakamoto Yasuhiko 
Published: May 2009

AbstractThe reaction of ethyl 3‐ethoymethylene‐2,4‐dioxovalerate (EMDV) (1) with 2‐aminobenzamide (2), 2‐aminobenzthioamide (3), 2‐aminobenzmethylamide (4) and 3‐amino‐2‐methyl‐ or phenylpyrazole‐4‐carbox‐amides (6 and 7) produced ethyl 3‐aminomethylene‐2,4‐dioxovalerates (10, 15, 16, 18 and 19), which led to pyrrolo[1,2‐a]quinazoline‐1,5‐diones (11, 22 and 23) and pyrrolo[1,2‐a]pyrazolo[4,3‐e]pyrimidine‐1,5‐diones (24 and 25) under the acidic condition, respectively. Analogously, 2‐aminothiophenol reacted with 1 to give 21, which was subsequently derived to pyrrolo[1,2‐a]benzothiazolin‐l‐one (26) under the neutral condition. Furthermore, we prepared the heterocyclic steroidal molecules (41, 43, 45, 47, 49 and 51) by condensation of 11 and 26 with hydrazine, methylhydrazine and phenylhydrazine.
Induction asymétrique et réaction des α‐hydroxy‐oximes avec le bromure de phenylmagnésium. Synthéses stéreoselectives d'alcools aziridiniques et d'aza‐bicyclo[3.1.0]oxo‐2 oxaisothiazolidines‐1,2,3
Authors: Laurent AndrÉ , Marsura Alain , Pierre Et Jean‐Louis 
Published: May 2009

AbstractUne méthode simple de synthése d'aziridines alcools (NH) est decrite: action du réactif de Grignard sur les α‐hydroxy‐oximes (solvant toluéne). Ces composés ont été cyclisés en oxo‐2 oxaisothiazolidines. L'utilisa‐tion de l'effet Overhauser permet d'attribuer une configuration à ces composés et d'en déduire celle des aziridines alcools correspondantes. Une preuve de la complexation du réactif de Grignard avec la fonction alcool est apportée par action du bromure de méthyl magnésium sur la phényl‐2 méthanol‐3 azirine. L'induc‐tion asymetrique observée est discutée à partir d'un état de transition tenant compte de la complexation du réactif de Grignard avec la fonction alcoolate.
Reissert compound studies. XXXV. Acid‐catalyzed condensations of the phthalazine reissert compound and condensations of phthalazine reissert compound salt
Authors: Bhattacharjee D. , Popp F. D. 
Published: May 2009

AbstractThe phthalazine Reissert compound hydrofluoroborate undergoes condensation with alkynes to give pyrrolo[2,1‐α]phthalazines and with alkenes to give 2‐(1‐phthalazyl)pyrroles. The phthalazine Reissert compound undergoes acid catalyzed condensations with some alkenes but the intermediate is of sufficient stability to be isolated. This same type of intermediate can also be isolated in the acid‐catalyzed hydrolysis of the phthalazine Reissert compound.
2‐Imidazolines. IV . 1‐Aryl‐2‐alkylthio‐4,5‐ diamino‐4,5‐dihydroimidazoles. Synthesis and properties
Authors: Meola Stefania , Rivera Elisabetta , Stradi Riccardo , Gioia Bruno 
Published: May 2009

Abstract1,2‐Diimmonium salts (1) react with S‐substituted isothioureas (3) yielding 2‐alkylthio‐4,5‐diamino‐4,5‐dihydroimidazoles (4), which under mild pyrolytic conditions afforded 2‐alkylthio‐5‐aminoimidazoles (7). Imidazolines (4) and imidazoles (7) were easily desulfurated with Raney nickel affording 4,5‐diamino‐4,5‐dihydroimidazole (9) and 5‐aminoimidazole (10), respectively.
Synthesis of 1,4‐disubstituted quinolizidines
Authors: Lal Bansi , Bhedi D. N. , Dornauer H. , De Souza N. J. 
Published: May 2009

AbstractTwo 9,11‐seco‐aphylline derivatives and four 4‐substitutedimino‐1‐carbethoxyquinolizidines were synthesized. Conformational assignments of the predominant isomers were derived from spectral data.
Synthesis of 5H‐benzoxazolo[3,2‐a]quinazolin‐5‐ones
Authors: Kim Dong Han 
Published: May 2009

Abstract5H‐Benzoxazolo[3,2‐a]quinazolin‐5‐ones (Xa‐d) were synthesized in excellent yields from N‐(2‐hydroxyphenyl)anthranilic acids (Ia‐d) and cyanogen bromide. The synthesis was based on the mechanistic consideration of the reactions of salicylic acid with cyanogen bromide previously reported in the literature. A versatile alternative route to these novel heterocyclic compounds was through thermal cyclization of N‐(2‐benzoxazolyl)‐2‐fluorobenzamides (XIII) obtained by reacting 2‐fluorobenzoyl chloride with 2‐aminobenzoxazoles. The reaction of Xb with ethanol in the presence of potassium hydroxide gave an ethoxyquinazolinone (XVII). Similarly, the alkaline hydrolysis of Xb afforded an quinazolindione (XVIII).
Synthesis of nectriapyrone
Authors: Abramson Hanley N. , Wormser Henry C. 
Published: May 2009

AbstractA totally synthetic route to the antibacterial fungal metabolite nectriapyrone (1) has been achieved by condensation of methylmalonyl dichloride with ethyl trans‐4‐methyl‐3‐oxo‐4‐hexenoate followed by hydrolysis, decarboxylation, and methylation of the resulting 3‐methyl‐4‐hydroxy‐5‐carbethoxy‐6‐(trans‐1‐methyl‐1‐propenyl)‐2‐pyrone. Exploration of an alternate scheme involving the dehydrogenation of 6‐substituted‐4‐methoxy‐5,6‐dihydro‐2‐pyrones, prepared by Reformatsky reaction of ethyl γ‐bromo‐β‐methoxycrotonate with various aldehydes, was abandoned since it did not appear to have general applicability to the preparation of nectriapyrone and its analogs.
Functionalization of substituted 2‐(1H)pyridones. I. A novel synthesis of a‐arylgyloxylates and related systems
Authors: Showalter H. D. Hollis , Haskell Theodore H. 
Published: May 2009

AbstractA novel synthetic strategy is presented in which the heteroaryl[(trimethylsilyl)oxy]acetonitrile intermediate 3 is utilized either as a homologation or reverse‐polarity synthon for convenient entry into its corresponding α‐hydroxy‐ and α‐ketoarylalkanoate 4 and 6, respectively. Further functionalization, including a stereo‐selective oximation procedure, is described.
Synthesis ofN,N'‐Diacyl‐1,2‐di‐(4‐pyridyl)ethylenedianiines
Authors: Braña M. F. , Rodriguez Maria L. López , Garrido J. , Roldán C. M. 
Published: May 2009

AbstractReaction ofN‐(4‐pyridylmethyl)benzamideN‐oxides with acetic anhydride yielded dimerization compounds. This dimerization occurs at the atom attached to the pyridine ring. These compounds so obtained were evaluated for analgesic and antiinflammatory activity.
Pyrazolo[1,5‐d]triazines‐1,2,4. I. Dérivés pyrazoliques
Authors: Lancelot Jean‐Charles , Maume Daniel , Robba Max 
Published: May 2009

AbstractLa synthese d'intermédiaires pyrazoliques destinés à ětre mis en oeuvre dans des réactions de cyclisation ou de réarrangement menant à des pyrazolo[1,5‐d]triazines‐1,2,4 est décrite. Il s'agit de dérivés où le pyrazole est substitué en 5 par des groupements hydrazide ou hydrazone et éventuellement bromés en 4. Les (pyrazolyl‐5)‐2 oxadiazoles‐1,3,4 et thiadiazoles‐1,3,4 sont accessibles par cyclisation d'hydrazides pyrazoliques avec l'oxychlorure ou de décasulfure de phosphore. La formation de dihydro‐1,2 oxo‐1 (ou thioxo‐1) pyrazolo[1,5‐d]triazines‐1,2,4 est observée dans quelques cas. Les structures sont établies par rmn.
Unusual friedel‐crafts reactions. 3. Synthesis of 2,4‐Diethoxychromans and their conversion into benzopyrylium perchlorates
Authors: Bigi Franca , Casiraghi Giovanni , Casnati Giuseppe , Sartori Giovanni 
Published: May 2009

AbstractBy a coordinated reaction of phenols (I) and malonaldehyde‐bis‐(diethylacetal) (II) at ambient temperature, under unusual Friedel‐Crafts conditions, a class of new compounds, 2,4‐diethoxychromans (IV) has been synthesized. Subsequent treatment of IV in acetic acid with 70% perchloric acid produces 1‐benzopyrylium perchlorates (V).
Photochemical substitution reactions of 4‐Pyridinecarbonitrile with aliphatic alcohols in neutral and acidified medium
Authors: Carolina Tullio , Clerici Angelo , Coggiola Dianella , Morrocchi Sergio 
Published: May 2009

AbstractChemical evidence is given that the title photo‐reactions proceed via hydrogen abstraction by the photo‐excited base from the alcohol in neutral medium and via electron‐transfer process between the photo‐excited base and the alcohol in hydrochloric acid acidified medium.
Synthesis of 1‐aryl‐3‐trifluoromethyl‐5‐methylthio‐1,2,4‐triazoles from 2‐arylmethylisothiosemicarbazides and 1,1,1‐trichloro‐3,3,3‐trifluoroacetone
Authors: Pilgram Kurt H. , Skiles Richard D. 
Published: May 2009

AbstractThe reaction of 1,1,1‐trichloro‐3,3,3‐trifluoroacetone with S‐methyl‐2‐arylisothiosemicarbazides affords an unusual synthesis of 1‐aryl‐3‐trifluoromethyl‐5‐methylthio‐1,2,4‐triazoles from which 1‐aryl‐3‐trifluoromethyl‐1,2,4(4H)‐triazole‐5‐ones are obtained on treatment with base.
Synthesis and anticonvulsant activity of 3‐amino‐4(3H)‐quinazolinones
Authors: Kornet M. J. , Varia T. , Beaven W. 
Published: May 2009

AbstractSeveral 3‐amino‐4(3H)‐quinazolinones were prepared from o‐aminobenzoylhydrazines and triethyl orthoformate or from isatoic anhydrides, hydrazines and triethyl orthoformate. o‐Aminobenzoylhydrazine intermediates were obtained by reaction of isatoic anhydrides with hydrazines. Some of the aminoquinazolinones displayed anticonvulsant activity in mice.
On triazoles. V. Synthesis of 1‐ and 2‐R1‐3‐R2,R3‐amino‐5‐amino‐1,2,4‐triazoles
Authors: Reiter JÓZsef , Pongó László , Somorai Tamás , Dvortsák PÉTer 
Published: May 2009

AbstractThe correct isomeric and tautomeric structure of different 1‐ and 2‐R1‐3‐R2,R3‐amino‐5‐amino‐1,2,4‐triazole derivatives prepared from the correspondingN‐cyano‐N'‐R2,R3‐S‐methyl‐isothioureas and the corresponding hydrazines was proved with the help of their ir, uv,1H‐nmr and13C‐nmr spectra as well as the uv spectra of the Schiff bases of an isomeric pair.
Chemical reactions of cycloalkanespirohydantoins. Part 2. Synthesis of new 4‐hydroxyimidazolidinone N3‐substituted from cycloalkanespirohydantoins
Authors: Salazar Loreto , Rubido Julia , Espada Modesta , Pedregal Carmen , Trigo Gregorio , Elguero José 
Published: May 2009

AbstractN3‐Substituted hydantoins have been to undergo lithium aluminum hydride reduction (THF, room temperature, 5 hours) to give 4‐hydroxy‐2‐imidazolidinones in good yields.
Réductions chimique et électrochimique de benzopyranno‐1 as‐triazines
Authors: Bellec Christian , Vinot Nicole , Maitte Pierre 
Published: May 2009

AbstractLa réduction électrochimique des benzopyranno‐1‐(4,3‐e]‐as‐triazinones‐3 fournit un dérivé dihydrogéné‐1,4 qui se réarrange en dihydro‐4,4a, celui‐ci est réductible ultérieurement avec contraction de cycle et conduit aux benzopyrannoimidazolones. L'action des organomagnésiens sur les benzopyranno‐1 as‐triazines provoque la réduction en α du noyau aromatique (dihydro‐4,4a) tandis que la réduction électrochimique conduit, via les dihydro‐1,4, à des dérivés dihydrogénés en position‐1,10a. Les dihydro‐1,4 benzopyrannotriazines subissent également par réduction une contraction du cycle triazine, fournissant des benzopyrranoimidazoles. Les dihydro‐1,10a, selon qu'elles possèdent ou non le motif hydrazone, sont réduites en imidazoles ou conduisent aux dérivés tétrahydrogénés.
Preparation of reissert compounds derived from the thieno[3,2‐c]pyridine, thieno[2,3‐d]pyridazine and the thieno[2,3‐d]pyrimidine ring systems
Authors: New J. S. , Jass P. A. , Barrett K. A. 
Published: May 2009

AbstractThe use of tributyltin cyanide, trimethylsilyl cyanide and potassium cyanide in the Reissert reaction is contrasted in the furo[3,2‐c]pyridine, thieno[3,2‐c]pyridine, thieno[2,3‐dpyridazine, and thieno[2,3‐d]pyrimidine ring systems.
The reaction of ethyl chromone‐2‐carboxylates with 1,2‐diaminobenzene
Authors: Markees Diether G. 
Published: May 2009

AbstractEthyl chromone‐2‐carboxylate and all its benzoanalogs were prepared and caused to react with 1,2‐diami‐nobenzene to give 2‐(2‐hydroxybenzoyl)methinyl‐3‐oxo‐1,2,3,4‐tetrahydroquinoxaline and its benzo analogs. The condensation products of diethyl oxalate and methyl hydroxyaryl ketones which were required for the preparation of the starting esters, were found to be subject to ring chain tautomerism.
Synthesis and reactions of “biginelli‐compounds”. Part I
Authors: Kappe Christian Oliver , Roschger Peter 
Published: May 2009

AbstractVarious reactions of 2‐oxo(or thioxo)‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylic acid derivatives (Biginelli‐compounds) were investigated. The site of methylation and acylation on 6‐methyl‐4‐phenyl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylic acid ethyl ester 1a and its 2‐oxo derivative 9a was studied. The synthesis of pyrimido[2,3‐b]thiazines and thiazolo[3,2‐a]pyrimidines was accomplished by condensation of 1a with 1,3‐and 1,2‐dielectrophiles. A Dimroth‐like rearrangement yielding 6H‐1,3‐thiazines can be observed when 1a was treated with dimethylformamide and phosphorus oxychloride. The formation of indeno[1,2‐d]pyrimidines can be achieved by intramolecular Friedl‐Crafts acylation of 9a and 13, respectively. Finally a route for the preparation of 4,6‐disubstituted‐pyrimidine‐5‐carbonitriles is presented, starting with Biginelli‐compound 25.