bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Progress of Diamond Device toward Power Application
Authors: Shikata Shinichi , Ikeda Kazuhiro , Kumaresan Ramanujam , Umezawa Hitoshi , Tatsumi Natsuo
Published: March 2009

Diamond is nominated as a material candidate for future high power device due to its superior material properties and resulting very high FOM. In this paper, our recent progresses and the expected possibilities of diamond for power electronics applications are introduced as short review. Firstly for the epitaxial growth, by adopting step-flow epitaxial growth by off- angle substrate with optimized growth conditions, we have succeeded in reducing these killer defects almost six orders from 106cm-2 to almost 100cm-2 levels. For the substrate, our recently developed technology to fabricate diamond plates from bulk, 12x13mm2 size are available to use, that can avoid fabrication difficulties with small size substrate. Secondly for the device, primitive studies showed possibly for the advantage of diamond such as low reverse leakage current, high temperature and high current density operation.
Molecular characterization of the entomopathogenic fungiLecanicilliumspp. (Deuteromycota: Hyphomycetes) isolated from white pine weevil,Pissodes strobi(Coleoptera: Curculionidae), in British Columbia
Authors: Leal Isabel , Alfaro René I. , Lim Young Woon , Kope Harry H.
Published: March 2009

The entomopathogenic fungal genusLecanicilliumGams and Zare includes species that are highly pathogenic to many genera of insects. Three species,Lecanicillium longisporum(Petch) Zare and W. Gams,L. muscarium(Petch) Zare and W. Gams, andL. pissodisKope and Leal, were found to be entomopathogens of adult white pine weevils,Pissodes strobi(Peck), in coastal British Columbia. Morphological characteristics were used to identify these species, but variation in conidial shape and size made it difficult to classify some of the isolates into the correct species ofLecanicillium. To confirm the identity of theseLecanicilliumspecies, we used molecular tools such as polymerase chain reaction – restriction fragment length polymorphism and DNA sequencing.
Seasonal dynamics of Urophora quadrifasciata on spotted knapweed in the Arkansas Ozarks
Authors: Duguma Dagne , Kring Timothy J. , Wiedenmann Robert N.
Published: March 2009

Periodic sweep-net sampling and capitula sampling were conducted between April and October 2007 to determine the seasonal phenology of Urophora quadrifasciata (Meigen) (Diptera: Tephritidae) on spotted knapweed, Centaurea stoebe subsp. micranthos (Gugler) Hayek (Asteraceae), in the Arkansas Ozarks of the United States of America. Urophora quadrifasciata produces up to three generations in Arkansas, rather than being bivoltine as in the northern United States of America. The first, second, and third generations of U. quadrifasciata reached peak adult numbers around 26 May, 29 June, and 27 July, respectively. Males tended to emerge earlier than females but the female:male ratio was approximately 1:1 for most of the season. The majority of the offspring of the three generations emerged between June and October, while approximately 38% entered diapause and emerged as adults in April-June of the following year; 3.4 ± 0.1 (mean ± SE) (range 1–12) flies emerged from each infested capitulum. The absence of other, competing knapweed biological control agents as well as very low rates of parasitism, mild weather conditions, and a longer knapweed growing season likely contributed to the adaptation and establishment of U. quadrifasciata on spotted knapweed in Arkansas.
Optimizing Deepwater Well Locations To Reduce the Risk of Shallow-Water-Flow Using High-Resolution 2D and 3D Seismic Data
Authors: McConnell Daniel R.
Published: March 2009

Interpreting possible overpressured sands with geophysical data, inpractice, is best accomplished by doing a combined interpretation using bothconventional exploration 3D and high-resolution 2D seismic data. The use ofhigh-resolution ‘hazards’ 2D seismic data, can, if interpreted together with 3Dseismic data on a workstation, significantly aid in optimizing well locationsto reduce the risk of overpressured sands.

Introduction

Drilling through overpressured sands in the tophole section of deepwaterwells can result in a difficult and expensive well-control problem known as"shallow-water-flow"(SWF). SWF-prone sediments are common in the deepwater Gulfof Mexico. And, it is often common for these problem intervals to cover thedrilling target so that the interval cannot be easily avoided. High-resolution2D seismic data is routinely acquired for obtaining a permit for drilling, butthe data are usually interpreted only for that purpose. High-resolution 2D datasets, however, are very useful in SWF assessment studies. Exploratory 3Dseismic data can image overall SWF-prone intervals, but in many cases lack theresolution to identify sand-prone sections in the required detail. High-resolution 2D seismic data, interpreted together with 3D seismic data, canbe used to identify well locations where SWF would not be expected or would beless severe.

The first part of this paper reviews the seismic data types that arecommonly used in SWF pre-drill assessment studies and their respectiveresolutions. The basic SWF model and the associated seismic facies that arecommonly the source of SWFs are also reviewed. Finally, two pre-drill SWFstudies, one from the middle continental slope at a water depth of 1,014 m(3,328 ft) and the other from the abyssal plain at the foot of the Sigsbee Escarpment at a water depth of 2,026 m (6,647 ft), both in the Gulf of Mexico, are discussed.
Effects of realism on extended violent and nonviolent video game play on aggressive thoughts, feelings, and physiological arousal
Authors: Barlett Christopher P. , Rodeheffer Christopher
Published: March 2009

Previous research has shown that playing violent video game exposure can increase aggressive thoughts, aggressive feelings, and physiological arousal. This study compared the effects that playing a realistic violent, unrealistic violent, or nonviolent video game for 45 min has on such variables. For the purpose of this study, realism was defined as the probability of seeing an event in real life. Participants (N=74; 39 male, 35 female) played either a realistic violent, unrealistic violent, or nonviolent video game for 45 min. Aggressive thoughts and aggressive feelings were measured four times (every 15 min), whereas arousal was measured continuously. The results showed that, though playing any violent game stimulated aggressive thoughts, playing a more realistic violent game stimulated significantly more aggressive feelings and arousal over the course of play. Aggr. Behav. 35:213–224, 2009. © 2009 Wiley‐Liss, Inc.
Iron‐Mediated Cleavage of CC Bonds in Vicinal Tricarbonyl Compounds in Water
Authors: Mecinović Jasmin , Hamed Refaat B. , Schofield Christopher J.
Published: March 2009

Drei von einer Sorte: Vicinale Tricarbonyl‐Verbindungen gehen Eisen(III)‐vermittelte C‐C‐Spaltungen ein (siehe Schema). Die Ergebnisse sind relevant für den Aminosäurenachweis durch Ninhydrin und für den Vitamin‐C‐Stoffwechsel.

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From Metacyclophanes to Cyclacenes: Synthesis and Properties of [6.8]3Cyclacene
Authors: Esser Birgit , Bandyopadhyay Arkasish , Rominger Frank , Gleiter Rolf
Published: March 2009

Conjugated belts: [6.8]3cyclacene as the first hydrocarbon cyclacene was synthesized in a de novo strategy. Various [23]metacyclophanes are described as intermediates. The synthetic approach was extended to larger cyclacenes, and [24]metacyclophanes as precursors of [6.8]4cyclacene were synthesized.

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In this article we show synthetic pathways to [6.8]ncyclacenes demonstrated by the de novo synthesis of [6.8]3cyclacene as the first purely hydrocarbon cyclacene and of precursors for [6.8]4cyclacene. The design of the de novo synthesis by exploring alternative pathways is discussed and various precursors are shown. Crucial to the synthesis of [6.8]3cyclacene were two cyclization steps. The first is a Wittig trimerization reaction which yielded the hexamethyl substituted all‐cis‐[23]metacyclophanetriene. For the second cyclization step the methyl groups were converted to aldehyde functionalities by two subsequent oxidation steps of N‐bromosuccinimide (NBS) bromination and oxidation with 2‐iodoxybenzoic acid (IBX). The final cyclization of the second set of double bonds was achieved by a McMurry‐coupling reaction. Towards the synthesis of [6.8]4cyclacene different synthetic pathways to methyl substituted all‐cis‐[24]metacyclophanetetraenes were explored. Insights into the structures of [23]metacyclophanetri‐ and [24]metacyclophanetetraenes were gained by X‐ray crystallographic investigations on various intermediates. A crystallographic analysis of [6.8]3cyclacene revealed a D3h symmetrical structure with planar benzene rings and a formation of tubular structures in the solid state.
The effect of crystal surface roughness on impurity adsorption
Authors: Ferreira A. , Faria N. , Rocha F.
Published: March 2009

The effect of crystal surface roughness on impurity adsorption was investigated in a fluidized bed crystallizer and in a batch crystallizer. The crystallisation of sucrose in pure and impure systems was the study subject. Calcium chloride was utilized as impurity in this work. The results show that the impurity adsorption is growth rate dependent and is strongly influenced by the crystal surface properties. Crystals with high surface roughness have lower impurity adsorption. Based on experimental evidences, a new theoretical model is proposed to quantify the surface roughness influence on the impurity adsorption, allowing, by operating at the more adequate supersaturation, to control the impurity transfer into crystals. The used impurity does not have a significant influence on the growth rates at the studied temperatures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solvothermal syntheses and crystal structures of two 4‐heterocyclic acylpyrazolone complexes
Authors: Li Jingqi , Li Jinzhou , Zhang Hengqiang , Li Jing
Published: March 2009

Many explorations of transition metal (M)‐L system under solvothermal condition, have led to the syntheses of two new 4‐heterocyclic acylpyrazolone complexes [Co(L)2(CH3OH)2] (HL = 1‐phenyl‐3‐methyl‐4‐(2‐furoyl)‐5‐pyrazolone) (1) and [Cr(L)3] (2). Single‐crystal X‐ray analyses reveal that crystal structures of compound1and2are respectively orthorhombic, Pbca,a= 15.0378(6) Å,b= 9.8405(4) Å,c= 20.7321(8) Å, V = 3067.9(2) Å3, Z = 8 and triclinic, P‐1,a= 10.7966(18) Å,b= 13.023(2) Å,c= 15.520(3) Å, α = 73.011(4)°, β = 84.884(4)°, γ = 70.267(4)°, V = 1964.3(6) Å3, Z = 2. Complex1has a two‐dimensional (2D) network structure that is formed by O–H···N H‐bonding interactions. Complex2makes a one‐dimensional (1D) zigzag chain structure by intermolecular π···π interactions, which is further interlinked via C–H···N H‐bonding interactions to generate a 2D sheet, and then a three‐dimensional (3D) supramolecular network structure is further linked by intermolecular C–H···π interactions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of KDP crystal grown from solution with low pH value
Authors: De‐Gao Zhong , Bing Teng , Sheng‐Ming Dong , Qing‐Guo Wang , Yan‐Shuai Zhao , Wan‐Xia Huang , Tao Yu
Published: March 2009

Solubility curves of KDP (KH2PO4) in solutions with different pH values were measured. It was found that the solubility of KDP crystal increased with the reduction pH value of solution. Transparent KDP crystal was grown from solution with 1.5 pH by point seed. Chemical etching experiments revealed that pyramid sector of the crystal displayed more growth defects. Growth defects, such as growth striation and inclusion, were analyzed by white‐beam synchrotron radiation X‐ray topography. The reasons for the formation of these growth defects were discussed. Transmittance spectra test of both prismatic sector and pyramidal sector was performed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cod liver oil, other dietary supplements and survival among cancer patients with solid tumours
Authors: Skeie Guri , Braaten Tonje , Hjartåker Anette , Brustad Magritt , Lund Eiliv
Published: March 2009

The effect of various dietary supplements on chronic diseases and mortality has been widely studied, but few convincing results have emerged from studies in well‐nourished populations. In Norway, both cod liver oil and other dietary supplements are frequently used. In the Norwegian Women and Cancer cohort study, we explored if supplement use before diagnosis affected survival of cancer patients with solid tumours. We performed Cox proportional hazards analyses, adjusting for age at diagnosis, smoking and stage. Cod liver oil was the most frequently used dietary supplement, followed by multivitamins and minerals. Whole year daily use of cod liver oil was associated with lower risk of death in patients with solid tumours [RR = 0.77 (95% CI 0.61–0.97)] and in lung cancer patients [RR=0.56 (95% CI 0.34–0.92)]. Also daily and occasional use of other dietary supplements decreased the risk of death among lung cancer patients [RR = 0.70 (95% CI 0.49–0.99) and 0.55 (95% CI 0.31–0.97)]. More research is needed to clarify the association; meanwhile adjustment for dietary supplement use should be performed in survival analyses of lung cancer patients. © 2009 UICC
Prion protein ablation increases cellular aggregation and embolization contributing to mechanisms of metastasis
Authors: Muras Angelita G. , Hajj Glaucia N.M. , Ribeiro Karina B. , Nomizo Regina , Nonogaki Sueli , Chammas Roger , Martins Vilma R.
Published: March 2009

Cellular Prion Protein (PrPC) is a cell surface protein highly expressed in the nervous system, and to a lesser extent in other tissues. PrPC binds to the extracellular matrix laminin and vitronectin, to mediate cell adhesion and differentiation. Herein, we investigate how PrPC expression modulates the aggressiveness of transformed cells. Mesenchymal embryonic cells (MEC) from wild‐type (Prnp+/+) and PrPC‐null (Prnp0/0) mice were immortalized and transformed by co‐expression of ras and myc. These cells presented similar growth rates and tumor formation in vivo. When injected in the tail vein, Prnp0/0ras/myc cells exhibited increased lung colonization compared with Prnp+/+ras/myc cells. Additionally, Prnp0/0ras/myc cells form more aggregates with blood components than Prnp+/+ras/myc cells, facilitating the arrest of Prnp0/0ras/myc cells in the lung vasculature. Integrin αvβ3 is more expressed and activated in MEC and in transformed Prnp0/0 cells than in the respective Prnp+/+ cells. The blocking of integrin αvβ3 by RGD peptide reduces lung colonization in transformed Prnp0/0 cells to similar levels of those presented by transformed Prnp+/+ cells. Our data indicate that PrPC negatively modulates the expression and activation of integrin αvβ3 resulting in a more aggressive phenotype. These results indicate that PrPC may have main implications in modulating metastasis formation. © 2009 UICC
Rheological blends for drug delivery. II. Prolongation of nerve blockade, biocompatibility, and in vitro–in vivo correlations
Authors: Hoare Todd , Bellas Evangelia , Zurakowski David , Kohane Daniel S.
Published: March 2009

Rheological polymer blends of hyaluronic acid (HA) and hydroxypropylmethyl cellulose (HPMC) were evaluated as prolonged duration delivery vehicles for local anesthetics using a rat sciatic nerve blockade model. HA‐HPMC blends extended the duration of sensory block approximately threefold compared to that achieved using a bupivacaine solution. Blending HA and HPMC facilitated the injection of higher polymer concentration delivery vehicles and reduced the rate of polymer hydration compared to HA solutions, enabling prolonged drug release. The duration of effective nerve block was correlated with each of the zero shear viscosity, polymer concentration, yield stress, and gel point frequency of the blends, while a two‐parameter model correlating duration of nerve block with zero shear viscosity and humectancy provided improved fits to the in vivo data compared to any single variable alone. The blends exhibited no cytotoxicity and induced only a mild short‐term inflammatory reaction in vivo at the site of injection, with all blends largely resorbed 4 days postinjection. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Reaction of sulfene with heterocyclic N,N‐disubstituted α‐aminomethyleneketones. IX. Synthesis of 1,2‐oxathiino[6,5‐e]indole derivatives
Authors: Mosti Luisa , Schenone Pietro , Menozzi Giulia , Cafaggi Sergio
Published: March 2009

The polar 1,4‐cycloaddition of sulfene to N,N‐disubstituted 5‐aminomethylene‐1,5,6,7‐tetrahydro‐1‐methylindol‐4‐ones occurred only in the case of aliphatic N‐substitution to give, generally in good yield, 4‐dialkylamino‐3,4,5,6‐tetrahydro‐7‐methyl‐7H‐1,2‐oxathiino[6,5‐e]indole 2,2‐dioxides IV. Full aromatization of IVa (4‐NR2 = dimethylamino) with DDQ in refluxing benzene gave in low yield 7‐methyl‐7H‐1,2‐oxathiino‐[6,5‐e]indole 2,2‐dioxide, whereas the same reaction of IVe (4‐NR2 = morpholinyl) with excess DDQ afforded in low yield 7‐methyl‐4‐morpholinyl‐7H‐1,2‐oxathiino[6,5‐e]indole 2,2‐dioxide.
Reaction of sulfene with heterocyclicN,N‐disubstituted α‐aminomethyleneketones. X. Synthesis of thieno[2,3‐h]‐1,2‐benzoxathiin derivatives
Authors: Mosti Luisa , Schenone Pietro , Menozzi Giulia , Romussi Giovanni
Published: March 2009

The polar 1,4‐cycloaddition of sulfene toN,N‐disubstituted (E)5‐aminomethylene‐6,7‐dihydrobenzo[b]‐thiophen‐4(5H)ones II gave in excellent yield and only in the case of aliphaticN‐substitution,N,N‐disubstituted 4‐amino‐3,4,5,6‐tetrahydrothieno[2,3‐h]‐1,2‐benzoxathiin 2,2‐dioxides III, which are derivatives of the new heterocyclic system thieno[2,3‐h]‐1,2‐benzoxathiin. Dehydrogenation with DDQ of cycloadducts IIIa‐d was successful only in the case of IIIa (NR2= dimethylamino) to give in low yield 4‐dimethylamino‐3,4‐dihydrothieno[2,3‐h]‐1,2‐benzoxathiin 2,2‐dioxide.
Synthesis of 4(3H)‐quinazolinones from derivatives of methyl 2‐isothiocyanatobenzoate
Authors: Dean William D. , Papadopoulos Eleftherios P.
Published: March 2009

EthylN‐(2‐methoxycarbonylphenyl)thiocarbamate (2),N‐(2‐ethoxycarbonylphenyl)‐4‐methoxythiobenz‐amide (3b), and 2‐(4‐methoxyphenyl)‐4H‐3,1‐benzothiazin‐4‐one (4a), react with nucleophilic reagents containing at least one primary amino group to yield a variety of 2‐substituted and 2,4‐disubstituted 4(3H)quinazolinones, as well as some tricyclic and tetracyclic products.
Synthesis and biological activity of (3,5‐disubstituted‐1H‐1,2,4‐triazol‐1‐yl)benzophenone derivatives
Authors: Hirai Kentaro , Sugimoto Hirohiko , Ishiba Teruyuki , Fujishita Toshio , Tsukinoki Yuji , Hirose Katsumi
Published: March 2009

The synthesis of (5‐acylaminomethyl‐3‐carbamoyl‐1H‐1,2,4‐triazol‐1‐yl)benzophenone derivatives 4a‐i, 14a‐d, 15a‐d, 16a‐c, is described. Acylation of the key intermediate, 1‐benzoylphenylazo‐1‐aminoacetamide 7, followed by cyclization in the presence of acid afforded 1H‐1,2,4‐triazole derivatives. These compounds were evaluated for their central nervous system (CNS) activity. Some of these compounds exhibited high activities in anti‐pentylene tetrazole and rotarod test in mice when orally administered.
Reduction of 4,7‐diphenyl‐1,2,5‐thia(oxa)diazolo[3,4‐c]pyridines affording 2,5‐diphenyl‐3,4‐diaminopyridines and ring closure of the diamines to fluorescent azaheterocycles
Authors: Mataka Shuntaro , Takahashi Kazufumi , Imura Tetsuro , Tashiro Masashi
Published: March 2009

Reduction of 4,7‐diphenyl‐1,2,5‐thia‐ (1a‐i) and 1,2,5‐oxadiazolo[3,4‐c]pyridines (3a and c‐e) gave 3,4‐diamino‐2,5‐diphenylpyridines (2a‐g), which were converted into the fluorescent triazolo[4,5‐c]‐(5), 1,2,5‐selenadiazolo[3,4‐c]‐ (6), imidazolo[4,5‐c]pyridines (8), and pyrido[5,6‐c]pyridines (11). In the reduction of 3a, c and e, 4,5‐dihydro[1,2,5]oxadiazolo[3,4‐c]pyridines (4a‐c) were obtained.
Benzo[b]thiophene derivatives. XXVI. 5‐methoxy‐6‐chloro‐3‐β‐acetamidoethylbenzo[b]thiophene, a blocked analog of melatonin
Authors: Campaigne E. , Smith Homer A. , Sandhu J. S. , Kim Chung S.
Published: March 2009

A potential anti‐ovulatory agent, 5‐methoxy‐6‐chloro‐3‐β‐acetamidoethylbenzo[b]thiophene, a sulfur analog of melatonin having the 6‐position blocked to inhibit oxidative metabolism, has been synthesized from 3‐hydroxy‐4‐chloroacetophenone.
Reaction of β‐aminocrotonamide with dibasic acid derivatives
Authors: Sato Masayuki , Ogasawara Hiromichi , Kato Tetsuzo
Published: March 2009

Reaction of β‐aminocrotonamide (1) with succinic anhydride gave β‐succinaminocrotonamide (3a), which was treated with base to cyclize to 3,4‐dihydro‐6‐methyl‐4‐oxo‐2‐pyrimidinepropanoic acid (4a). Similarly, pyrimidinepentanoic acid derivative 4b was prepared from compound 1 and glutaric anhydride. Reaction of compound 1 with glutarate, adipate, and phthalate gave the corresponding pyrimidines 4b, 4c and 4d, while reaction of compound 1 with malonate gave 2‐hydroxypyridine derivative 11 and dimethylpyrimidinone 4e. Reaction of dimethyl fumarate with compound 1 in the presence of methoxide gave a poor yield of pyrrolo[3,4‐c]pyridine derivative 13.
Hydrosulfite reduction ofN‐nitroso‐1,2,3,4‐etrahydroisoquinolines and oxidation ofN‐amino‐l,2,3,4 tetrahydroisoquinolines
Authors: Powell Burwell F. , Overberger C. G. , Anselme J.‐P.
Published: March 2009

The sodium hydrosulfite reduction ofN‐nitroso‐1,2,3,4‐tetrahydroisoquinoline (5) does not result in the loss of nitrogen and leads to the corresponding hydrazine6which upon oxidation with mercuric oxide in ethanol at 62° gives the hexahydrotetrazine7in 39% yield. Treatment of theN‐tosyl derivative of6with base affords7in nearly quanitative yield. Oxidation of6in 1‐butanol at 95° results in the formation of a complex product mixture from which only one component, 1,1′‐azobis‐3,4‐dihydroisoquinoline (8) could be isolated. Surprisingly the sodium hydrosulfite reduction of 2‐nitroso‐3‐phenyl‐1,2,3,4‐tetrahydroisoquinoline (15) also failed to proceed with loss of nitrogen and yields the corresponding hydrazine16. However,16was cleanly oxidized by mercuric oxide in ethanol at 62° with concurrent elimination of nitrogen to afford 2‐phenylindane in 75% yield. Possible rationalizations for these results are presented.
A novel synthesis of fused imidazo[5,1‐c]‐1,2,4‐triazoles
Authors: Abd Allah Sanaa O. , Ead Hamed A. , Kassab Nazmi A. , Zayed Mohey M.
Published: March 2009

The new fused imidazo[5,1‐c]‐1,2,4‐triazoles 4 were obtained by cyclization of the corresponding 2‐imidazolidinone 4‐phenylhydrazones 2 which were obtained by the action of phenylhydrazine on the arylmethylene derivatives of 4‐thioxo‐2‐imidazolidinone 1. The benzylimino derivatives 6 were obtained by the reaction of benzylamine with 1. Alkylation of 1 with phenacyl bromide and/or ethyl bromoacetate afforded the S‐alkyl derivatives 7.
Photocycloaddition of benzophenone to α‐angelicalactone and thermal rearrangement of the product
Authors: Bolíiavar R. A. , Tasayco M. L. , Rivas C. , Leon V.
Published: March 2009

α‐Angelicalactone dissolved in thiophene in the presence of benzophenone was irradiated with uv light in order to find out if the unsaturated lactone behaves either as an olefin capable of yielding a [2 + 2] adduct with the heterocycle or if it rather reacts as a substrate for the excited benzophenone. The isolation of two isomeric oxetanes indicates that the latter is the preferred reaction pathway. One of the oxetanes undergoes an interesting thermal rearrangement.
Ring opening of aryl cyclopropyl ketones to l‐Acyl‐l,l,3‐tribromo‐ propanes and their cyclization to 2‐Aryl‐3,3‐dibromo‐2‐methoxy and ‐2‐cyanotetrahydrofurans
Authors: Takahashi Masahiko , Takeshi Noriaki , Myojoh Kohji , Sano Hideyuki , Morisawa Toshio
Published: March 2009

The reaction of aryl cyclopropyl ketones 1 with excess bromine gave l‐acyl‐l,l,3‐tribromopropanes 2, which were cyclized to 2‐aryl‐3,3‐dibromo‐2‐methoxytetrahydrofurans 3 on treatment with alkaline in aqueous methanol. 2‐Aryl‐3,3‐dibromo‐2‐cyanotetrahydrofurans 5 were obtained by the reactions of 2 with sodium cyanide.
Dérivés de l'hydroxyméthyl‐5 furfural. I. Synthése de dérivés du di‐ et terfuranne
Authors: El‐Hajj Toni , Martin Jean‐Claude , Descotes Gérard
Published: March 2009

La condensation d'hydroxymethyl‐5 furfural ou d'aldéhydes furanniques dérivés avec des composes car‐bonylés ou sulfonés éthyléniques permet l'obtention de dérivés de la butanedione‐1,4 dont la cyclisation conduit á des di‐ et terfurannes substitues ou non.
Reaction of sodium cyanide with 2H‐pyran‐2‐thiones and their 3‐bromo derivatives
Authors: Mishrikey Morcos Michael
Published: March 2009

The reaction of sodium cyanide with 4,5,6‐triaryl‐2H‐pyran‐2‐thiones and their 3‐bromo derivatives led to the formation of 2,5‐dihydrothiophenes.
Novel heterocycles. 10. Reactions of 1,3,2‐benzodiazaphosphorin‐4(1H)‐one 2‐oxides
Authors: Coppola Gary M.
Published: March 2009

Reactions of 1,3‐disubstituted‐2,3‐dihydro‐1,3,2‐benzodiazaphosphorin‐4 (1 H)‐one 2‐oxides (1) with various electrophiles were investigated. The treatment of 1 with aldehydes in the absence of a basic catalyst directlyafforded alcohols 7a‐h in good yield. The product from the reaction of 1 with chloral, on treatment with sodium hydride, resulted in the formation of a dichloroepoxide (8). When 1 was allowed to react with isocyanates or isothiocyanates in the presence of triethylamine, amides 10a‐e and thioamide 11 were produced in good yield. Compounds 1a and 1b were readily halogenated on their phosphorus atom by treatment with either carbon tetrachloride or carbon tetrabromide and triethylamine. The P‐chloro compound 12a reacted with ethanol to furnish the P‐ethoxy derivative 13 and, in an attempt to react 12a with bis (2‐chloroethyl) amine, anhydride 14 was formed in high yield. Spectral data for the majority of the products are also discussed.
Reaction of N‐amino‐4,6‐dimethylpyrimidinium mesitylene sulfonate with nucleophiles . A 15n‐study
Authors: van der Plas Henk C. , Baloniak Sylwester , Jongejan Hugo
Published: March 2009

Reaction of N‐amino‐4, 6‐dimethylpyrimidinium mesitylene sulfonate with liquid ammonia, with an aqueous solution of sodium hydroxide or with hydrazine leads to 3, 5‐dimethylpyrazole. Reaction of this salt with 15N‐labelled hydrazine gave incorporation of nitrogen‐15 in 3,5‐dimethylpyrazole and in recovered starting material. Evidence has been presented that the initial step in the ring contraction with hydrazine is the addition of the nucleophile to C‐2 and C‐6. It is suggested that in the presence of a base the reactive species is probably 4,6‐dimethylpyrimidinio amide.
Oxidation and photochemical reactions of 3‐phenyl‐2H‐1,4‐benzoxazines
Authors: Battistoni P. , Bruni P. , Fava G. , Tosi G.
Published: March 2009

3‐Phenyl‐2H‐1, 4‐benzoxazines 4‐oxides are light sensitive compounds, irradiation leads to 3‐phenyl‐2H‐1,4‐benoxazines and to their 3‐oxidized derivatives, whenever possible. Intermediate oxaziridines are formed during the photolysis and transformed into stable nitroxide radicals. The structure of these radicals was confirmed through peracid oxidation of 3‐phenyl‐2H‐1,4‐benzoxazines and 3‐phenyl‐3, 4‐dihydro‐2H‐1,4‐benzoxazines. A reaction mechanism is proposed on the basis of experimental observations.
Synthesis of all of the monomethyl isomers of naphtho[2,1‐b]thiophene
Authors: Tominaga Yoshinori , Tedjamulia Marvin L. , Castle Raymond N. , Lee Milton L.
Published: March 2009

All isomers of the monomethylnaphtho[2,1‐b]thiophenes were synthesized by photocyclization of 2‐styryl‐thiophenes which were either prepared by the Wadsworth‐Emmons reaction or by the condensation of 2‐lithiothiophene with the corresponding carbonyl compounds.
Ring opening reactions of indeno[1,2‐c]isoxazolones
Authors: Lemke Thomas L. , Sawhney Kailash N.
Published: March 2009

Nucleophilic attack of 8‐substituted indeno[1, 2‐c]isoxazol‐7‐ones (1) and 3‐phenylindeno[1, 2‐c]isoxazol‐4‐one (4) by dimethylsulfoxide or triphenylphosphine results in cleavage of the nitrogenoxygen bond of the isoxazole ring leading to the formation of sulfoximides (2 and 5) and phosphazenes (3 and 8).
Reactions of some 5‐substituted imidazo[2,1‐b]‐1,3,4‐thiadiazoles
Authors: Hough T. L.
Published: March 2009

The conversion of the 5‐bromoimidazo[2, 1‐b]‐1, 3, 4‐thiadiazole Ib to the 5‐cyano derivative Ic is firstly described. The 5‐nitroimidazo[2, 1‐b]‐1, 3, 4‐thiadiazole Id is smoothly reduced by aluminium amalgam to the 5‐imino‐5, 6‐dihydroimidazo[2, 1‐b]‐1, 3, 4‐thiadiazole II. However, reaction of Id with sodium dithionite unexpectedly gives 1, 3, 4‐thiadiazoles III and V depending upon conditions.
4‐Azapteridines. I. Covalent addition products of the pyrazino[2,3‐e]‐as‐triazine ring system
Authors: Tzeng Cherng Chyi , Panzica Raymond P.
Published: March 2009

Ring closure of 5, 6‐diamino‐3‐methylthio‐as‐triazine with 40% aqueous glyoxal provided the 6, 7‐dihydrate of the pyrazino[2, 3‐e]‐as‐triazine (4‐azapteridine) ring system. The C7 hydroxy group of this dihydrate underwent exchange in methanol or ethanol affording the 7‐alkoxy, 6‐hydroxy derivatives.
The synthesis of dinaphthothiophenes
Authors: Tedjamulia Marvin L. , Tominaga Yoshinori , Castle Raymond N. , Lee Milton L.
Published: March 2009

The synthesis of dinaphtho[1,2‐b:2′,3′‐d]thiophene (6), dinaphtho[2,1‐b:2′,3′‐d]thiophene (15), dinaphtho‐[1,2‐b:1′,2′‐d]thiophene (20), dinaphtho[2,1‐b:1′,2′‐d]thiophene (26), dinaphtho[2,3‐b:2′,3′‐d]thiophene (37) and dinaphtho[1,2‐b:2′,1′‐d]thiophene (45) has been accomplished.
Stereochemical studies. 58. Saturated heterocycles. 39. Preparation and steric structures of dihydro‐1,3‐oxazines, 1,3‐oxazin‐2‐ones and 1,3‐oxazine‐2‐thiones fused with norbornane and norbornene
Authors: Stájer1 Géza , Szabó Enikö A. , Fülöp Ferenc , Bernáth Gábor , Sohár Pál
Published: March 2009

3‐endo‐Aminobicyclo[2.2.1]hept‐5‐ene‐2‐endo‐carboxylic acid (1), prepared from endo‐norborn‐5‐ene‐2,3‐dicarboxylic acid anhydride, and the analogous saturated cis‐exo‐amino acid (3) were reduced with lithium aluminum hydride to the aminoalcohols 2 and 4; the latter were cyclized by means of arylimino ethers to methylene‐bridged tetrahydro‐ (6a‐c) and hexahydro‐3,1‐benzoxazines (7b‐d), respectively. The endo (2) and exo (4) aminoalcohols were converted to methylene‐bridged tetrahydro‐3,1‐benzoxazin‐2‐one (9) and hexahydro‐3,1‐benzoxazin‐2‐one (12) with ethyl chloroformate and sodium methoxide; treatment of the alcohols with carbon disulfide gave, via the dithiocarbamates, the corresponding 2‐thiones (11, 13). The structures were confirmed by ir and nmr spectroscopy.
Reactions of 1‐glucosyl‐5‐nitro‐1,2,4‐triazole with nucleophiles
Authors: Camarasa María José , De Las Heras Federico G.
Published: March 2009

1‐Glucosyl‐5‐nitro‐1,2,4‐triazole reacted with nucleophiles, such as water, aziridine, chloride ion and 4‐dimethylaminopyridine to give the corresponding 5‐substituted 1‐glucosyl‐1,2,4‐triazole derivatives.
New synthesis of 11‐acyl‐5,11‐dihydro‐6H‐pyrido[2,3‐b][1,4]‐benzodiazepin‐6‐ones and related studies
Authors: Kovač T. , Oklobdžija M. , Comisso G. , Decorte E. , Fajdiga T. , Moimas F. , Angeli C. , Zonno F. , Toso R. , Šunjić V.
Published: March 2009

New synthesis of 11‐acyl‐5,11‐dihydro‐6H‐pyrido[2,3‐b][1,4]benzodiazepin‐6‐ones (42‐44) is reported. The crucial steps (Scheme VI) represented N‐oxydation of 1 (1A) to 35 (35A), facilitated ring‐closure of 36 into 37, its subsequent N‐α‐chloroacetylation to 38, aminolysis to 39‐41 (involving N‐O anchimeric assistance as depicted in 38A) and deoxygenation to 42‐44 (Scheme VII). The central intermediate 37 is also obtained on oxygenation of 2, a new synthesis of which was reported in the previous paper of this series [3]. Other attempts of cyclisation “from the top” or “from the bottom” (Scheme I) are described. Thus, interaction of 1 with acetamide afforded 3 and 4 instead of the expected 2A. Compound 5 cyclised into 3‐pyridoquinazolone 6 while its 2‐(4′‐methylpiperazin‐1′‐yl analogue 9 was observed to be unstable for the attempted ring‐opening and reclosure to 42. “From the bottom” cyclisations of 10A‐10C, via intermediary amines 11A‐11C failed and pyridoquinazolinone 13 was isolated (Scheme V). The attempted oxidative cyclisation of the compounds 15 and 18 into 2 and 42, respectively, 13 afforded imidazolo[5,4‐b]pyridine derivative (18–19), while 15 remained unchanged. 3‐Acylamino‐2‐arylaminopyridines (21‐24), cyclised into imidazolopyridines 29‐30. Model compounds 45‐50 were prepared to study selective aminolysis of the chlorine atoms in 2‐chloro‐3‐(2′‐chlorobenzoyl)aminopyridine 1, and its N‐oxide 35.
New efficient total syntheses of derivatives of protoporphyrin‐IX bearing deuteriated methyl groups
Authors: Smith Kevin M. , Pandey Ravindra K.
Published: March 2009

New total syntheses of hemins which are regioselectively deuteriated in the 1,5 (2), 5 (3) or 8 (4) methyl groups are described. Syntheses of hemins 2 and 3 follow the progression from pyrromethane 12 to t‐butyl tripyrrene‐carboxylate hydrobromide (17 and 30) and then to a,c‐biladiene dihydrobromide (19 and 31), but for reasons of economy in use of labeled monopyrroles, the o,c‐biladiene dihydrobromide 40 for hemin 4 is approached in an initially “clockwise” manner by synthesis of a benzyl tripyrrene‐carboxylate hydrobromide 37 from the pyrromethane 5. Cyclization of the a,c‐biladienes (19, 31, and 40) was accomplished by brief heating in dimethylformamide in the presence of copper(II) chloride.
o‐Hydroxyphenylureas. Intermediates in the urea fusion synthesis of 2‐benzoxazolinones
Authors: Nachman Ronald J.
Published: March 2009

o‐Hydroxyphenylureas have been identified as intermediates in the urea fusion synthesis of 2‐benzoxazolinones. The pyrolysis of these intermediates represents a new alternate synthesis of the benzoxazolinone ring system.
On the assignment of the 13C‐NMR spectrum of phenothiazine
Authors: Hallberg A. , Al‐Showaier I. , Martin A. R.
Published: March 2009

The assignment of the 13C‐nmr spectrum of phenothiazine was made by comparison with the 13C‐nmr spectrum of 1,9‐dideuteriophenothiazine, synthesized via repeated lithiations and subsequent deuterations of phenothiazine.
Autocorrelated 13c‐13c double quantum coherence two‐dimensional nmr spectroscopy: Utilization of a modified version of the technique as an adjunct in the total assignment of the 1h‐ and 13c‐nmr spectra of the mutagen phenanthro[3,4‐b]thiophene
Authors: Musmar M. J. , Willcott M. Robert , Martin Gary E. , Gampe Robert T. , Iwao Masatomo , Lee Milton L. , Hurd Ralph E. , Johnson Leroy F. , Castle Raymond N.
Published: March 2009

Development of successively higher field nmr spectrometers has facilitated the study of increasingly more complex molecules, although smaller molecules such as phenanthro[3,4‐b]thiophene still offer very substantial assignment problems because of the highly congested nature of their 1H‐ and 13C‐nmr spectra. Assignments of such spectra, if they are to be unequivocal, frequently require the utilization of two‐dimensional nmr spectroscopic techniques. Total assignments of the 1H‐ and 13C‐nmr spectra of phenanthro[3,4‐b]thiophene are reported. Assignments were based on a conventional high resolution 500 MHz 1H‐nmr spectrum, autocorrelated two‐dimensional 1H‐nmr spectra (COSY), two‐dimensional 1H‐13C chemical shift correlation spectra and a modified version of autocorrelated 13C‐13C double quantum coherence two‐dimensional nmr spectroscopy. From NOE measurements, a separation of 1.99 Å between H1 and H11 was computed, suggesting that phenanthro[3,4‐b]thiophene has a pronounced helical conformation in solution.
2,1‐Benzisothiazoles. XII. . The use of n‐substituted‐2,1‐ benzisothiazolium salts as synthetic equivalents of o‐aminobenz‐ aldehydes. A simple synthesis of some 2‐Quinolones
Authors: Davis Michael , Hudson Michael J.
Published: March 2009

N‐Substituted‐2,1‐benzisothiazolium salts 2 react with ethyl cyanoacetate in pyridine solution to give substituted 3‐cyano‐2‐quinolones 5.
A comparison of some friedel‐crafts and grignard reactions of optically active phenyloxirane
Authors: Taylor Stephen K. , Haberkamp William C. , Brooks Dee W. , Whittern David N.
Published: March 2009

The Friedel‐Crafts reactions of optically active phenyloxirane with toluene and anisole were examined for stereospecificity. The enantiomeric ratios of the diarylethanol products were determined and compared to those of the same products obtained from the reaction of p‐tolyl and p‐methoxyphenyl Grignard reagents with optically active phenyloxirane. The p‐tolyl Grignard and Friedel‐Crafts products gave similar enantiomeric ratios (approximately 64:36 and 60:40, respectively). However, in the p‐methoxyphenyl products from the Grignard and Friedel‐Crafts reactions, different enantiomers predominated (ratios of 33:67 and 62:38, respectively).
Convenient preparative methods for N‐aryl‐γ‐pyridones from γ‐pyrones
Authors: Looker James H. , Cliffton Michael D.
Published: March 2009

2‐Hydroxymethyl‐5‐methoxy‐4‐H‐pyran‐4‐one (1) reacts with aniline and six aniline derivatives in very dilute aqueous hydrochloric acid at reflux temperature to give the N‐aryl‐γ‐pyridone. A second procedure utilizes the aromatic amine hydrochloride by reacting it with 1 in aqueous medium at reflux temperature. p‐Nitroaniline hydrochloride and 1 give the N‐aryl‐γ‐pyridone in 65% yield, as opposed to 12% from the dilute acid procedure.
Thermal fragmentations of nitrated 8‐quinolinols
Authors: Sutter Peter , Weis Claus D.
Published: March 2009

8‐Quinolinols which are substituted in the aromatic nucleus by nitro‐, chloro‐, or by sulfonic acid groups underwent a neat thermal fragmentation upon heating in 75% nitric acid as reaction medium yielding 2,3‐dicarboxypyridinium nitrate. The scope and the mechanism of these reactions are discussed.
Preparation of 5‐sulfonylpyrimidines from β‐keto, β‐cyano‐, and β‐ethoxycarbonyl‐β‐sulfonylenamines
Authors: Takahashi Masahiko , Mamiya Tsutomu , Wakao Makoto
Published: March 2009

β‐Keto‐β‐sulfonylenamines 2a,b reacted with benzamidine or guanidines to give 2,4‐disubstituted 5‐methanesulfonylpyrimidines 3a‐d, whose methanesulfonyl groups were substituted by n‐butyllithium or alkylmagnesium bromides to yield 2,4‐disubstitued 5‐alkylpyrimidines 6a‐d. 2‐Substituted 4‐amino‐5‐sulfonylpyrimidines 7a,b, 8 and 2‐substituted 5‐benzenesulfonylpyrimidin‐4‐ones 9a,b were similarly obtained from β‐cyano‐β‐sulfonylenamines 2c,d and β‐ethoxycarbonyl‐β‐sulfonylenamine (2e), respectively.
Synthesis and study of substituted coumarins. A facile preparation of D,L‐o‐tyrosine
Authors: Kokotos George , Tzougraki Chrysa
Published: March 2009

A general procedure for the preparation of aminocoumarins and aminohydroxycoumarins under mild conditions is described. Amino‐ and acetamidoaminocoumarins were prepared by reduction of the corresponding nitro derivatives with sodium borohydride in the presence of 10% palladium on charcoal. Acid hydrolysis of the acetamidoaminocoumarins with (a) concentrated hydrochloric acid in ethanol, or (b) with 1Nhydrochloric acid under reflux, gave diaminocoumarins and aminohydroxycoumarins, respectively. Condensation of the ethyl ester of glycine with salicylaldehyde gave 3‐salicylideneaminocoumarin (XIII), the Schiff base of 3‐aminocoumarin (XII). Acid hydrolysis of XIII under the above mentioned conditions, (a) and (b), gave XII and 3‐hydroxycoumarin (XVI), respectively. Hydrogenation of compound XIII in dioxane or in dimethylformamide with 10% palladium on charcoal gave 3‐salicylaminocoumarin (XVII), while hydrogenation of XII, XIII or XVII in acetic acid with traces of water and palladium black gave the amino acido‐tyrosine.
Synthesis of 4‐heterocyclyl‐hexahydro‐8‐methoxyfuro[3,2‐c]quinolines by Lewis acid catalyzed [4 + 2]cycloaddition reaction
Authors: Kametani Tetsuji , Furuyama Hiroko , Fukuoka Yukari , Takeda Hajime , Suzuki Yukio , Honda Toshio
Published: March 2009

Synthesis of 2‐substituted quinoline derivatives by Lewis acid catalyzed [4 + 2]cycloaddition was investigated.
Oxamates derived from 5‐aminopyrazoles
Authors: Peet Norton P.
Published: March 2009

Several oxamates were prepared from ethyl oxalyl chloride and 5‐amino‐4‐cyanopyrazoles substituted in the 1‐position with aryl, aroyl and arylsulfonyl groups. Both aroyl and arylsulfonyl groups suffered chloride‐induced cleavage during this process. The synthesis of 7‐(6‐chloro‐3‐pyridazinyl)‐7H‐pyrazolo[3,4‐d]‐1,2,3‐tri‐azin‐4(3H)‐one (11) and its reaction with methanol to give 1‐(6‐chloro‐3‐pyridazinyl)‐5‐methoxy‐1H‐pyrazole‐4‐carboxamide (12) are also reported. A mechanism for this interesting transformation is presented.
Long chain heterocyclic dyes. Part one. Hydrophobic structures
Authors: Barni Ermanno , Savarino Piero , Larovere Raffaella , Viscardi Guido , Pelizzetti Ezio
Published: March 2009

A series of polymethine dyes and of their precursors, containing long and short alkyl chains, was prepared and their chemical and spectroscopic (uv, 1H‐nmr) properties were briefly discussed. The electronic absorption spectra of the dyes in aqueous medium and in presence of anionic or cationic surfactants evidenced aggregation phenomena. The best deaggregating effect was shown by the anionic surfactant when added above its critical micellar concentration.
Benzocycloheptapyridines. Analogs of azatadine
Authors: Halczenko Wasyl , Shepard Kenneth L.
Published: March 2009

Certain 3‐substituted derivatives of cyproheptadine (1a) have been shown to possess potent pharmacological properties. The structural analogy between cyproheptadine and azatadine (2) prompted the preparation of 9‐substituted derivatives of2and its 5,6‐dehydro analog for pharmacological comparison. The 9‐cyano and 9‐trifluoromethylthio derivatives were prepared by direct displacement of the corresponding 9‐bromo compounds. Acid hydrolysis of the nitriles generated the carboxylic acids. Oxidation of the trifluoromethylthio compounds15aand18agave the epoxy sulfones19aand19b, which could not be deoxygenated. Therefore, the trifluoromethylsulfonyl moiety was introduced prior to the formation of the exocyclic olefin.
Intramolecular capture of pummerer rearrangement intermediates. I. Synthesis of pyrrolo[2,1‐c][1,4]benzothiazines
Authors: Bates Dallas K. , Winters R. Thomas , Sell Burnell A.
Published: March 2009

Treatment of 1‐(2‐alkylsulfinylphenyl)pyrroles with trifluoroacetic acid in refluxing toluene gives 4‐substituted pyrrolo[2,1‐c][1,4]benzothiazines in good yield when the alkyl group bears an electron withdrawing substituent on the α‐carbon. In the absence of such a group, starting material is recovered. The sulfoxides are prepared by oxidation (mCBPA) of the corresponding sulfide. The sulfides are prepared from 2‐aminobenzenethiol either by S‐alkylation followed by conversion to the pyrrole using 1,4‐dimethoxytetrahydrofuran in glacial acetic acid or by S‐alkylation of 1‐(2‐phenylmercapto)pyrrole followed by oxidation to the sulfoxide.
Synthesis of 1‐azapyrene
Authors: Tanga Mary J. , Reist Elmer J.
Published: March 2009

The environmental contaminants 1‐azapyrene 15, 2‐azapyrene 13 and several other azapyrene derivatives were synthesized from a common intermediate, 2,2a,3,4‐tetrahydrocyclopenta[cd]phenalen‐1‐one oxime 6. The synthesis of 1‐azapyrene 15 completes the series of azapyrenes.
The identification of 10 and 11 substituted 7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐ones through 1N NOE studies on their methyl p‐toluenesulfonate salts
Authors: Campbell Jack B. , Lavagnino Edward R. , Paschal Jonathan W.
Published: March 2009

The spectral similarities of 10 and 11 substituted 7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐ones hinder the identification of the individual isomers. Preparation of the 13‐methyl p‐toluenesulfonate salts of these compounds has allowed the assignment by the use of NOE techniques. Saturation of the N‐methyl caused an NOE at H‐12. The coupling pattern of H‐12 then provides identification of the compound.
Synthesis of [1,2,4]triazoloquinazolinones and imidazoquinazolinones
Authors: Murdoch Robert , Tully W. Roger , Westwood Robert
Published: March 2009

4‐Quinazolinones have been cyclised to [1,2,4]triazoloquinazolinones and to imidazoquinazolinones. The direction of cyclisation has been proved by the unambiguous synthesis of their ethylation products.
Synthesis of 5H‐benzimidazo[1,2‐a][1,3,4]thiadiazolo[2,3‐d][1,3,5]triazin‐5‐one and 12H‐benzimidazo[1,2‐a]pyrimido[6,1‐d][1,3,5]triazin‐12‐one, two new heterocyclic ring systems
Authors: Bossio Ricardo , Marcaccini Stefano , Parrini Valerio , Pepino Roberto
Published: March 2009

2‐(2,6‐Dimethylpyrimidin‐4‐ylaminobenzimidazole) (VIIa) and 2‐(1,3,4‐thiadiazol‐2‐ylamino)benzimidazole (VIIb) underwent a ring‐closure reaction with phosgene giving 1,3‐dimethyl‐12H‐benzirnidazo[1,2‐a]pyrirnido[6,1][‐d][1,3,5]triazin‐12‐one (IIa) and 5H‐benzimidazo[1,2‐a][1,3,4]thiadiazolo[2,3‐d][1,3,5]triazin‐5‐one (IIb) two hitherto unknown heterocyclic systems. A convenient synthesis of 2,6‐dimethyl‐4‐aminopyrimidine is described.
Synthesis of nitrogen‐containing heterocycles. 3. Formation and structure of new 1,2,4‐triazole derivatives
Authors: Miyamoto Yoshiko , Yamazaki Chiji
Published: March 2009

Treatment of N(3)‐[(2‐cyano‐2‐ethoxycarbonyl)vinyl]amino‐N(4),N(4)‐dimethylaminomethylenehydrazones of aromatic carbonyl compounds with hot acetic acid resulted in the formation of symmetrical gem‐bis‐(3‐dimethylamino‐1,2,4‐triazol‐1‐yl)methanes, (3‐dimethylamino‐1,2,4‐triazol‐1‐yl)arylmethyl acetates, and (3‐dimethylamino‐1,2,4‐triazol‐1‐yl)alkenes of a gem‐diaryl type depending upon whether the carbonyl compound was aldehyde or ketone.
Synthesis of antimicrobial agents. IV. synthesis of 1‐hydroxypiperazine dihydrochloride and its applications to pyridone carboxylic acid antibacterial agents
Authors: Uno Toshio , Okuno Toshimi , Taguchi Masahiro , Iuchi Koji , Kawahata Yoshihiro , Sotomura Mikio , Tsukamoto Goro
Published: March 2009

1‐Hydroxypiperazine dihydrochloride 7 was prepared and it was applied to the syntheses of new pyridone carboxylic acid antibacterial agents (PCA‐antibacterial agents). 1‐Cyclopropyl‐6,8‐difluoro‐1,4‐dihydro‐7‐(4‐hydroxypiperazin‐1‐yl)‐4‐oxoquinoline‐3‐carboxylic acid 13 showed the most potent antibacterial activity.
A short and stereoselective synthesis of (±)‐aristeromycin
Authors: Hutchison Alan , Grim Michael , Chen Jen
Published: March 2009

A new Stereoselective three‐step total synthesis of (±)‐aristeromycin starting from readily available 1‐hydroxymethyl‐3‐cyclopentene is described.
Electrochemical oxidation of 2,4,5‐triaryl‐substituted pyrroles. II. Oxidative dimerization of 4,5‐diphenyl‐2‐mesitylylpyrrole
Authors: Silvestri G. , Gambino S. , Filardo G. , Petruso S. , Caronna S. , Sprio V.
Published: March 2009

2,4,5‐Triaryl‐substituted pyrroles lead, upon chemical or electrochemical oxidation, to an intermediate β‐β'‐dimer, which, in the course of the reaction, undergoes further oxidation to a tetracyclic derivative. To improve the selectivity towards the uncyclized dimer the oxidation of a triarylpyrrole in which the ortho positions of the phenyl group in position 2 are hindered by the presence of methyl groups was attempted. The cyclization was hindered, but an α‐β'‐dimer was obtained as the major product. An unexspected isomeric α‐β'‐dimer, in which the mesitylyl group is shifted into the β position of the pyrrole ring which undergoes the oxidation, was obtained in minor amounts. Electroanalytical data indicate that the process goes through the formation of a monomeric radical cation, followed by a slow chemical reaction.
Pyrazolo[3, 4‐d]pyrimidines related to lonidamine
Authors: Gatta Franco , Luciani Maria , Palazzo Giuseppe
Published: March 2009

This paper describes the synthesis of several pyrazolo[3, 4‐d]pyrimidines and tricyclic compounds with an imidazole, triazole or tetrazole ring fused to the pyrazolo[3, 4‐d]pyrimidine ring system, in an angular position (C‐4 and N‐5). All compounds reported herein contain the same substituent as “Lonidamine”, namely the 2, 4‐dichlorobenzyl group, attached to the pyrazole nucleus.