bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing the Mid-Term Competitiveness of a Semiconductor Manufacturing Factory through Collaborative Yield Learning Planning
Authors: Wang Yi Chi , Chen Toly , Li Kun Tai
Published: March 2009

Product yield is undoubtedly the most critical factor to the competitiveness of a
semiconductor manufacturing factory. Therefore, evaluating the competitiveness of a semiconductor
manufacturing factory based on the yields of all its products is a reasonable idea. For this purpose, a
systematic procedure is established to evaluate the mid-term competitiveness of a semiconductor
manufacturing factory in which the yield learning processes of all its products are considered
simultaneously. After that, for products that are not competitive enough but have strong demand, a
correction mechanism is designed to enhance their competitiveness at the expense of the other
products that are competitive but have no market. The whole process is therefore called collaborative
yield learning planning. To evaluate the advantages or disadvantages of the proposed methodology, it
has been applied to the data collected from a semiconductor manufacturing factory. Experimental
results supported the practicability and usefulness of the proposed collaborative yield learning
planning approach.
Stresses in Multilayered Ceramics Subjected to Biaxial Flexure Tests
Authors: Hsueh C.H.
Published: March 2009

Although standard test methods for biaxial strength measurements of ceramics have been established and the corresponding formulas for relating the biaxial strength to the fracture load have been approved by American Society for Testing and Materials (ASTM) and International Organization for Standardization, respectively, they are limited to the case of monolayered discs. Despite the increasing applications of multilayered ceramics, characterization of their strengths using biaxial flexure tests has been difficult because the analytical description of the relation between the strength and the fracture load for multilayers subjected to biaxial flexure tests is unavailable until recently. Using ring-on-ring tests as an example, the closed-form solutions for stresses in (i) monolayered discs based on ASTM formulas, (ii) bilayered discs based on Roark’s formulas, and (iii) multilayered discs based on Hsueh et al.’s formulas are reviewed in the present study. Finite element results for ring-on-rings tests performed on (i) zirconia monolayered discs, (ii) dental crown materials of porcelain/zirconia bilayered discs, and (iii) solid oxide fuel cells trilayered discs are also presented to validate the closed-form solutions. With Hsueh et al.’s formulas, the biaxial strength of multilayered ceramics can be readily evaluated using biaxial flexure tests.
Space Resolved Optical Emission Spectroscopy During Deposition of BaxSr1-xTiO3 Thin Films by Double Hollow Cathode Plasma Jet System
Authors: Olejníček J. , Hubička Zdenek , Čada M. , Virostko P. , Kment Štepan , Adámek P. , Jastrabik Lubomir , Dejneka A.
Published: March 2009

Pulse modulated double hollow cathode RF plasma jet system with two separate independent nozzles made of BaTiO3 (BTO) and SrTiO3 (STO) was used for deposition of BSTO thin films on Si and on multi-layer Si/SiO2/TiO2/Pt substrates. Dielectric properties of BSTO layers strongly depend on ratio composition expressed by parameter x = Ba/(Ba+Sr) and on accuracy in presence of other elements. Space resolved optical emission spectroscopy (OES) was used mainly for monitoring of concentration of particles sputtered from the hollow cathode and for feedback correction of power supplied in both nozzles because applied power was responsible for sputtering speed of Ba and Sr particles. Main attention was focused on relation between ratio of spectral intensity of Ba, Ba+, Sr and Sr+ lines close to substrate and ratio of Ba and Sr concentration in the deposited film. 2D map of emission lines intensity distribution for Ba, Ba+, Sr, Sr+, Ti, Ar, and Ar+ for double hollow cathode plasma jet system with BTO and STO nozzles was created. OES was also used for observing of excess of Ti particles in final layer with negative effect on layer properties and for measurement of rotational temperature of OH radicals. Preliminary results of all these optical measurements are published in this paper. Deposited thin films were analyzed by X-ray diffraction, which confirmed presence of BSTO and STO perovskite phase in the films, by atomic force microscopy (AFM), by electron microprobe and by micro-Raman scattering measurement.
Morphological Characterization of Sacrificial Layers of Porous Silicon for Photovoltaic Application
Authors: Ould-Abbas A. , Madani M. , Chabane Sari N.E.
Published: March 2009

We investigate the application of porous silicon (PS) in the field of the photovoltaic. In first step we realise a double porous silicon layer by electrochemical anodisation using two different current densities. The low current leads to a low porosity and during annealing, the recrystallisation of this layer allows epitaxial growth. The second current leads to a high porosity which permits the transfer onto a low cost substrate. During high temperature onto hydrogenation treatments of to passivate the structure and epitaxy in liquid phase, porous silicon is recristallized partially. In this work, a characterization by scanning electron microscopy informs us about the morphology of these porous layers.
Production of Small Pin by Micro/Meso-Scale Rotary Forming
Authors: Zhang Hua Ling , Makino Takehiko , Dohda Kuniaki , Cao Jian
Published: March 2009

Micro/meso-scale (from 0.1 to 10mm) metal parts are required in electronics and medical field in recent years. Rotary forming is one of possible methods to manufacture micro axial-symmetry parts. In rotary forming, the materials are rotated and compressed in radial directions. In order to investigate the basic deformation mechanism, flat dies are used. The pins with diameters of 0.3 to 0.8mm are used to clarify the effect of size of pins on deformation behavior. Additionally, the effect of lubrication conditions on the forming process is examined. It is considered that size effects in friction behavior are recognized to be large in micro/meso-scale rotary forming.
Total Synthesis of Hopeahainol A and Hopeanol
Authors: Nicolaou K. C. , Wu T. Robert , Kang Qiang , Chen David Y.‐K.
Published: March 2009

Similar, but different: Possessing almost the same but not identical structures, the recently discovered natural products hopeahainol A (1) and hopeanol (2) exhibit important but differing biological properties (see structures). Their first total synthesis has now been achieved through a series of novel cascade reactions and skeletal rearrangements.

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Study of electrocatalysts for oxygen reduction based on electroconducting polymer and nickel
Authors: Millán W. Martínez , Smit Mascha A.
Published: March 2009

The properties and electrocatalytic activity were studied of composite carbon‐supported materials based on heterocyclic polymer and nickel, in particular carbon/polyaniline/nickel, carbon/polypyrrole/nickel, carbon/poly(3‐methylthiophene)/nickel, as well as their precursors, carbon/polyaniline, carbon/polypyrrole, and carbon/poly(3‐methylthiophene). The materials were characterized by means of thermogravimetric analysis (TGA), scanning electron microscopy (SEM), EDAX, and electrochemical methods, such as cyclic voltammetry and linear voltammetry using RDE. SEM show porous materials, with a particle size of around 0.3 μm. It was found that in nickel‐modified catalysts between 5 and 6 wt % of nickel is obtained. TGA and FTIR show that the modification with nickel alters the polymer bonds. Curves from cyclic voltammetry show cathodic peaks corresponding to the oxygen reduction reaction (ORR) in all materials, occurring at relatively low potentials. Based on the potential range for ORR as well as kinetic parameters obtained from linear voltammetry using RDE, it was concluded that C‐Ppy‐Ni shows the best performance for ORR in acidic medium. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
[90Yttrium‐DOTA]‐TOC response is associated with survival benefit in iodine‐refractory thyroid cancer
Authors: Iten Fabienne , Muller Beat , Schindler Christian , Rasch Helmut , Rochlitz Christoph , Oertli Daniel , Maecke Helmut R. , Muller‐Brand Jan , Walter Martin A.
Published: March 2009

BACKGROUND:

The authors aimed to explore the efficacy of 90Yttrium‐1,4,7,10‐tetra‐azacyclododecane N,N′,N″,N‴‐tetraacetic acid [90Y‐DOTA]‐Tyr3‐octreotide (TOC) in advanced iodine‐refractory thyroid cancer.

METHODS:

In a phase 2 trial, the authors investigated biochemical response (assessed by serum thyroglobulin levels), survival, and the long‐term safety profile of systemic [90Y‐DOTA]‐TOC treatment in metastasized iodine‐refractory thyroid cancer. Adverse events were assessed according to the National Cancer Institute criteria. Survival analyses were performed by using multiple regression models.

RESULTS:

A total of 24 patients were enrolled. A median cumulative activity of 13.0 GBq (range, 1.7‐30.3 GBq) was administered. Response was found in 7 (29.2%) patients. Eight (33.3%) patients developed hematologic toxicity grade 1‐3, and 4 (16.7%) patients developed renal toxicity grade 1‐4. The median survival was 33.4 months (range, 3.6‐126.8 months) from time of diagnosis and 16.8 months (range, 1.8‐99.1 months) from time of first [90Y‐DOTA]‐TOC treatment. Response to treatment was associated with longer survival from time of diagnosis (hazard ratio [HR], 0.17; 95% confidence interval [CI], 0.03‐0.92; P = .04) and from time of first [90Y‐DOTA]‐TOC therapy (HR, 0.20; 95% CI, 0.04‐0.94; P = .04). The visual grade of scintigraphic tumor uptake was not associated with treatment response (odds ratio [OR], 0.98; 95% CI, 0.26‐3.14; P = 1.00).

CONCLUSIONS:

Response to [90Y‐DOTA]‐TOC in metastasized iodine‐refractory thyroid cancer was associated with longer survival. Upcoming trials should aim to increase the number of treatment cycles. Cancer 2009. © 2009 American Cancer Society.
Developing accurate industrial standards to facilitate production in apparel manufacturing based on anthropometric data
Authors: Hsu Chih‐Hung
Published: March 2009

Clothing and apparel are high value‐added products, and body measurement standards are crucial industrial standards in apparel manufacturing. These standards enable manufacturers to predict sales of different sizes and set production quantities accordingly, resulting in accurate material control and production planning. Many standards use a range of approximate girth differences based on anthropometric data to determine figure types, but these figure types cannot be accurately classified. Moreover, little research has been done to apply the girth ratio approach to identify figure types. This study proposes an accurate girth ratio approach to identify figure types for middle‐aged women; the approach can then be used to develop industrial standards. By applying these findings, figure types can be precisely classified. New body measurement standards can then be developed. These industrial standards can help manufacturers improve the fit of mass‐produced apparel, and their application in manufacturing can reduce production costs and increase market competitiveness. © 2009 Wiley Periodicals, Inc.
Application of the smiles rearrangement to the synthesis of 5,7‐disubstituted xanthone‐2‐carboxylic acids
Authors: Pfister Jürg R.
Published: March 2009

The depside‐like esters 3a and 3b underwent a Smiles rearrangement on treatment with base. The resulting diphenyl ethers 4a and 4b were converted into the xanthonecarboxylic acids 6a and 6b which are not readily accessible by other routes.
A new synthesis of 3(2H)‐furanones from acetylenic β‐diketones
Authors: El‐Kholy Ibrahim El‐Sayed , Mishrikey Morcos Michael , Marei Mohamed Gaber
Published: March 2009

Thermal cyclization of 1,5‐diarylpent‐1‐yne‐3,5‐diones led to the formation of 2‐benzyliden‐5‐aryl‐3(2H) furanones as well as 2,6‐diaryl‐4H‐pyran‐4‐ones as minor products. The structure of the furanones was established from their ir, 1H nmr and mass spectral data. Their reaction with hydrazine hydrate gave pyrazole derivatives.
Investigation on some (E)‐ and (Z)‐3‐heterocyclic‐substituted‐2‐phenylacrylic acids
Authors: Belgodere Elena , Bossio Ricardo , Cencioni Roberto , Pepino Roberto
Published: March 2009

The synthesis of 3‐(2‐thiazolyl)‐, 3‐(2‐benzothiazolyl)‐ and 3‐(2‐benzo[b] thienyl)‐2‐phenylacrylic acids is reported. Spectroscopic analyses and pK a determinations were found to be a convenient method for distinguishing the E and Z geometrical configurations.
Chemistry of thienopyridines. XXIX. The reissert‐henze reaction as a route to simple c‐substituents alpha to the heteronitrogen atom
Authors: Klemm L. H. , Muchiri Daniel R.
Published: March 2009

Treatment of a thienopyridine N‐oxide with benzoyl chloride and cyanide ion (Reissert‐Henze reaction) was shown to produce the corresponding cyanothienopyridine (43‐84% yield in three parent systems), wherein the cyano substituent occurs alpha to the heteronitrogen atom. In further transformations (in two systems) the cyano group was converted successively to carbamoyl (66‐89%),and thiocarbamoyl (3543%) functions. For 4‐substituted thieno[2,3‐6]pyridine 7‐oxides, methyl and chloro substituents were retained on Reissert‐Henze reaction, but the nitro group was replaced by CI or H. Some new TV‐oxides and TV‐oxide complexes are reported.
Ionic and radical addition of chlorine, bromine and some halogen systems of butadiene monoxide (4)
Authors: Shellhamer Dale F. , Green Richard C. , Luttrull Jeffrey K. , Seneker Stephan D. , Potter Mark K. , Heasley Victor L. , Heasley Gene E.
Published: March 2009

Ionic reactions of bromine, chlorine, methyl hypochlorite or N‐bromosuccinimide with butadiene monoxide (4) give only 1,2‐addition products. The Markownikoff (1‐halo‐2‐methoxy‐3,4‐epoxybutane) and anti‐Markownikoff (2‐halo‐1‐methoxy‐3,4‐epoxybutane) product ratios for ionic reaction of methyl hypochlorite and N‐bromosuccinimide in methanol with 4 are similar to those obtained with 1‐hexene. These data indicate that a rather symmetrical halonium ion is formed in the ionic halogenation of 4. Free radical reaction of bromine, chlorine, or trichloramine to 4 does not give ring‐opened products as one might expect for formation of an epoxy carbonyl intermediate. The mechanistic implications from these observations are discussed.
Synthesis of 1,4‐dihydro‐2‐methyl‐4‐oxo‐3‐quinolineglyoxylic acid and related compounds
Authors: Kurihara Takushi , Nasu Keiko , Mihara Kyoko
Published: March 2009

The synthesis of 1,4‐dihydro‐1‐methoxy or ethyl ‐2‐methyl‐4‐oxo‐3‐quinolineglyoxylic acid derivatives are described. α‐Acetoxy‐1,4‐dihydro‐1‐hydroxy‐2‐methyl‐4‐oxo‐3‐quinolineacetic acid esters (7a, 7a), which are key intermediates, were prepared by catalytic hydrogenation of 2‐acetoxy‐3‐acetyl‐4‐hydroxy‐4‐(2‐nitrophenyl) crotonic acid lactone (6) in methanol or ethanol.
Tetraoxo derivatives of perhydropyrrolo[3,4‐c]pyridine
Authors: Ferappi M. , Carotti A. , Casini G. , De Laurentis N. , Giardinà D. , Cingolani G. M. , Gavuzzo E. , Mazza F.
Published: March 2009

Michael adducts from diethyl fumarate with malonic esters or nitriles were cyclized to succinimide intermediates which, after glutarimide ring closure, afforded several N‐methyl and N‐benzyl derivatives of cis‐1,3,4,6‐tetraoxoperhydropyrrolo[3,4‐c]pyridine whose configuration was demonstrated by X‐ray crystal structure analysis.
A novel synthesis of diaminomethanes
Authors: Melis Stefana , Monni Francesca , Piras Pier Paolo , Sotgiu Francesca
Published: March 2009

Diaminomethanes have been synthesized by reaction of 1,3‐benzodioxole and 1,3‐benzoxathiole with a double amount of sodium dialkyl and alkyl aryl amides.
Bisallyl and bismethallyl derivatives of 2,3‐dihydroxypyridine
Authors: Jarvis Bruce B. , Anderson Catherine B.
Published: March 2009

2,3‐Dihyroxypyridine has been dialkylated with allyl bromide and methallyl chloride to give 1‐allyl‐3‐allyloxy‐2‐pyridone (2) and 1‐methallyl‐3‐methallyloxy‐2‐pyridone (3), respectively. These compounds readily undergo a Claisen rearrangement at 163° to give the bis‐1,4‐allyl‐3‐hydroxy‐2‐pyridone isomers, 4 and 5, respectively. 2,3‐Bisallyloxypyridine (8) and 2,3‐bismethallyloxypyridine (9) were synthesized from 2‐chloro‐3‐hydroxypyridine.
Studies on pyrrolidinones. Derivatives of 1,2,3,5,10,10a‐hexahydrobenz[f]indolizine‐3,10‐dione
Authors: Rigo Benoît , Kolocouris Nicolas
Published: March 2009

The Friedel‐Crafts reaction of N‐(arylmethyi)‐5‐pyrrolidinone‐2‐carboxylic acids gives either a cyclization or a reaction with benzene (used as a solvent). Reactions such as reduction, keto substitution and lactam ring opening of 1, 2, 3, 5, 10, 10a‐hexahydrobenz[f]indolizine‐3, 10‐diones obtained by the method above have been studied.
Heterocyclic rearrangements. Phenylhydrazones and N‐methyl‐N‐phenylhydrazones of 3‐acylisoxazoles
Authors: Vivona Nicolò , Macaluso Gabriella , Frenna Vincenzo , Ruccia Michele
Published: March 2009

The reaction of 3‐benzoyl‐5‐phenylisoxazole (4) and 3‐acetyl‐5‐methylisoxazole (5) with phenylhydrazine and N‐methyl‐N‐phenylhydrazine has been investigated and the reactivity of (E)‐ and (Z)‐phenylhydrazones and N‐methyl‐N‐phenylhydrazones has been studied.
Isomerisation, déshydration et réduction du méthyl‐4 dioxa‐1,6 spiro[4,5]decanol‐4. Obtention de précurseurs ou d'isomères de phéromones de guêpe
Authors: Cottier Louis , Mabilon Gil , Descotes Gérard
Published: March 2009

Le mélange des stéréosiomères des dioxaspirannols 1 obtenu par photolyse de l'(oxo‐3 n‐butyloxy)‐2 tétra‐hydropyranne, peut ětre enrichi par des méthodes chimiques en isomère cis(chlorure d'aluminium/acétate d'aluminium) ou trans (anhydride acétique puis hydrolyse). La thermolyse des acétates 2 ou des xanthates 5 conduit à un composé furannique 4, précurseur éventuel d'une dioxaspirolactone. La réduction des xanthates 5 donne les méthyl‐4 dioxaspirodécanes 8, isomères de position d'une phéromone de guěpe.
Synthèses d'hétérocycles indoliques à partir de dérivés carbonylés de l'indole et du pyrrole
Authors: Dupas Georges , Duflos Jack , Quéguiner Guy
Published: March 2009

Les réactions de l'azidoacétate d'éthyle avec le méthyl‐1 diformyl‐2, 3 indole (1) et son monoacétal méthylique 2 conduisent à des β et γ carbolines. La régiosélectivité de la condensation de l'aminoacétate d'éthyle avec 1 permet d'obtenir une γ carboline. Des dérivés d'un nouvel hétérocycle, le thiepino[4, 5‐b]indole sont décrits ainsi que leur application à I'obtention de dérivés carbazoliques.
Reaction of 3‐hetero‐substituted 2‐phenyl‐4‐thioxo‐3,4‐dihydro‐quinazolines with acyl chlorides and phenacyl bromides
Authors: Molina P. , Arques A. , Cartagena I. , Noguera J. A. , Valcarcel M. V.
Published: March 2009

Some 2, 5‐disubstituted 1, 3, 4‐thiadiazoles 5 were obtained by reaction of 3‐amino‐2‐phenyl‐4‐thioxo‐3, 4‐dihydroquinazoline (1) with acyl chlorides. Reaction of 3‐hydroxy‐2‐phenyl‐3, 4‐dihydroquinazoline (3) with phenacyl bromides was carried out either in dry acetonitrile or dimethylformamide to give 2‐phenyl‐4‐phenacylthio‐3‐quinazolinium N‐oxides 7 or 2‐phenyl‐4‐phenacylidene‐1H‐3‐quinazolinium N‐oxides' 8, respectively.
Differing reactivities and products in the reaction of some N‐methylimidazol‐2‐yl, oxazol‐2‐yl‐ and thiazol‐2‐ylsilanes and ‐stannanes with acid chlorides
Authors: Jutzi Peter , Gilge Ullrich
Published: March 2009

Some new N‐methylimidazoles, oxazoles and thiazoles (compounds 7‐15) with a keto‐function in the 2‐position have been synthesized by the reaction of heterocyclic substituted silanes and stannanes with the corresponding acid chlorides. In cases where the silylated heterocycles needed more drastic reaction conditions the use of the stannylated heterocycles was indicated. In the reaction of benzothiazol‐2‐yltrimethyl‐stannane (6) with acetyl chloride the ester 17 and the bibenzothiazolinylidene 18 were formed. The reaction of 6 with chloromethyl methyl ether afforded the olefin 19 as the only product. Mechanisms for the above reactions are discussed.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXVII. Two‐dimensional J‐resolved spectra of 1,4,9‐triazaphenoxathiin: The influence of frequency of the position and intensity of resonances due to strong coupling
Authors: Martin Gary E. , Gampe Robert T. , Ford Joseph J. , Robert Willcott M. , Morgan Michael , Ternay Andrew L. , Okafor Charles O. , Smith Keith
Published: March 2009

The synthesis of 1, 4, 9‐triazaphenoxathiin and the analysis of the two‐dimensional J‐resolved (2DJ) 1H‐nmr spectra of the molecule at 100 and 200 MHz are reported. Due to the strong coupling of the ABX and AB spin systems, additional resonances are observed in the 100 MHz 2DJ spectrum which are diminished in intensity and shifted further from F1 = O Hz in the case of the ABX system at 200 MHz, or which have disappeared in the 200 MHz spectrum in the case of the AB spin system. Calculated frequencies and intensities of the resonances due to strong coupling were found to be in excellent agreement with the observed data.
Reaktionen von elektronenreichen heterocyclen mit orthocarbonsäure‐derivaten. I. Zum reaktionsverhalten von acyclischen orthoestern mit indolen unter säurekatalyse
Authors: Akgün E. , Pindur U. , Müller J.
Published: March 2009

By kinetic controlled reaction of alkoxycarbenium‐ions 1a‐1d, generated in the medium, with the indoles 2a‐2c the methanes 3, 4 or the ketones 5 and 6 are the single products. In the reaction with 1d the minimum of reactivity is achieved. The experimental condition of the reactions allow an estimation of the reactivity of 1a‐1d and 2a‐2c.
Synthesis of substituted 3‐nitroso‐2,4‐pyridinediols for use as analytical reagents
Authors: Leard Robert E. , Bedenbaugh John H. , Bedenbaugh Angela O.
Published: March 2009

The 5‐bromo, 5‐iodo, and 5‐nitro derivatives of 6‐methyl‐3‐nitroso‐2,4‐pyridinediol were synthesized and shown to produce colored complexes with a number of Group VIII metal ions. Also synthesized were the 1‐pentyl and 1‐octyl esters of 4,6‐dihydroxy‐5‐nitrosopyridine‐3‐carboxylic acid. These compounds showed potential as solvent extraction reagents for certain Group VIII metals.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (isatoic anhydride). 11. Reaction of N‐methylisatoic anhydride with 1‐cyanoacetylpiperidine
Authors: Coppola Gary M. , Fu Emil W. , Shapiro Michael J. , Hartdmann Goetz E.
Published: March 2009

The reaction of N‐methylisatoic anhydride with 1‐cyanoacetylpiperidine in the presence of sodium hydride produces a tautomeric mixture of 4a and 4b, with 4b predominating. When heated in xylene, 4 is converted to the piperidine adduct 5 whereas heating in dimethylsulfoxide furnishes 3. Spectral data for 4 and 5 are also discussed.
1a,11b‐dihydrobenz[5,6]anthr[1,2‐B]azirine. A non k‐region polycyclic arene imine
Authors: Blum Jochanan , Ben‐Shoshan Shoshanna
Published: March 2009

The synthesis of the title compound 9 is described. Benz[a]anthracene 8,9‐oxide (6) was reacted with sodium azide in aqueous acetone and the trans‐9‐azido‐8,9‐dihydrobenz[a]anthr‐8‐ol (7), so formed, was cyclized by tri‐n‐butylphosphine. Attempts to dehydrogenate 10,11‐dihydrobenz[a]anthracene 8,9‐imine (4) with DDQ or by allylic bromination followed by base assisted dehydrobromination was unsuccessful. The N‐tosyl derivative of 4, prepared from the free imine, N,O‐bis(trimethylsilyl)acetamide and tosyl chloride underwent rapid aziridine‐ring cleavage by the silylating agent to give trans‐8,9,10,11‐tetrahydro‐8‐(4‐methyl)benzensulfon‐amido‐9‐ [(trimethyl)oxy]benz[a]anthracene (10).
Nitrile oxides cycloadditions to cinnamaldehyde. Facile dehydrogenation of 4‐formyl‐4,5‐dihydroisoxazoles
Authors: De Sarlo Francesco , Guarna Antonio , Brandi Alberto
Published: March 2009

Nitrile oxides (1) react with cinnamaldehyde (2) at the ethylenic double bond to give 4‐formyl‐4,5‐dihydro‐isoxazoles (3) as the predominant regioisomers (1H nmr). These primary cycloadducts easily dehydrogenate to the corresponding isoxazoles (4). In the presence of an excess of nitrile oxide (1), either the aldehydes (3) and (4) undergo further cycloaddition at the CO bond yielding the bis‐cycloadducts (5) and (6), respectively.
Synthesis of 2‐phenyl‐3,4‐dihydro‐2H‐ and ‐3,4,5,6‐tetrahydro‐2H‐1,6‐benzothiazocine derivatives
Authors: Press Jeffery B. , Eudy Nancy H.
Published: March 2009

The resynthesis of 2‐phenyl‐3,4‐dihydro‐2H‐benzothiazocin‐5(6H)‐one (1) was investigated in order to prepare derivatives with potential CNS activity. Lactam 1 could be converted to amidine derivatives 6a‐e via the intermediacy of the thioether 5a. Reduction of 1 with lithium aluminum hydride gave amine 8a. Reductive alkylation of 8a gave 9a and 9b while acylation of 8a gave derivatives 10a‐d. No interesting biological properties were found for these compounds.
Reaktionen von fulvenen mit 1,3‐dipolaren verbindungen. IV . Umsetzung des 6,6‐diphenylfulvens mit 2,4,6‐triphenylpyrylium‐3‐olat
Authors: Friedrichsen Willy , Seidel Winfried , Debaerdemaeker Tony
Published: March 2009

6,6‐Diphenylfulvene (6) reacts with 2,4,6‐triphenylpyrylium‐3‐olate (7) to give three [π2 + π‐4] cyclo‐adducts 8, 9, 10. Reduction of 8 with sodium borohydride yields a cage‐like compound 12 whereas the action of the same reagent on 9 results in the formation of three carbinols 13, 14, 15. Treatment of 9 with acetic acid/hydrogen chloride yields an isomer 18. The structures of both 12 and 18 have been established by X‐ray crystallography.
1,2,4‐triazines. 7. Regioselective n2‐amination of 3‐methylthio‐1,2,4‐triazin‐5(2H)‐ones.A novel synthesis of [1,2,4]triazolo[2,3‐b][1,2,4]triazinones and ‐triazine
Authors: Sanemitsu Yuzuru , Nakayama Yoshinori , Shiroshita Masao
Published: March 2009

A regioselective synthesis of 2‐aminotriazinones 6a‐d is reported, by reaction of 3‐methylthio‐1,2,4‐triazinones 5a‐d with O‐(2,4‐dinitrophenyl)hydroxylamine (2) as an amino‐transfer agent. A spectroscopic study and an unequivocal synthesis of 2‐amino‐4‐methyl‐6‐phenyl‐1,2,4‐triazinedione (11a) has shown the site of amination to be N2 of the 1,2,4‐triazinone ring. Subsequent reaction of 2‐amino‐1,2,4‐triazinones 6a‐b with amines, followed by ring closure with aliphatic acids provided [1,2,4]triazolo[2,3‐b][1,2,4]triazine‐7(1H)ones 13a‐e. Conversion of [1,2,4]triazolo[2,3‐b][1,2,4]triazinone 13c to unsubstituted [1,2,4]triazolo[2,3‐6][1,2,4]triazine (15) was attained.
A new aldehyde of the naphthyridine series
Authors: Sargin A. Necla
Published: March 2009

7‐Hydroxy‐1,8‐naphthyridine‐2,4‐dicarboxaldehyde (I) has been prepared.
Heterocyclic steroids. II. Synthesis of some spiro derivatives of 7,8‐diaza‐11‐oxasteroids
Authors: Altomare C. , Carotti A. , Campagna F.
Published: March 2009

A simple, one step conversion of aldol adducts 1 derived from cyclic 1,2,3‐tricarbonyl compound with 1,3‐cycloalkanediones into title compounds 2 is described.
Synthesis of 5,10‐dideazaminopterin
Authors: Degraw Joseph I. , Tagawa Hiroaki , Christie Pamela H. , Lawson John A. , Brown Edward G. , Kisliuk Roy L. , Gaumont Yvette
Published: March 2009

The synthesis of 5,10‐dideazaaminopterin by two independent routes is described. Condensation of the piperidine enamine of 4‐p‐carbomethoxyphenylbutyraldehyde (4) with ethoxymethylenemalononitrile followed by treatment of the resultant arylethylenaminomalononitrile (5) with methanolic ammonia produced 2‐amino‐3‐cyano‐5‐p‐carbomethoxyphenethylpyridine (6). Cyclization of the aminocyanopyridine with guanidine afforded 4‐amino‐4‐deoxy‐5,10‐dideazapteroic acid (8). Coupling of the pteroate intermediate with glutamate yielded the target 5,10‐dideazaaminopterin (10).

Alternatively, reduction of 2,4‐diamino‐6‐formyl‐5‐deazapteridine (11) with sodium borohydride gave the 6‐hydroxymethyl compound 12. Conversion to the bromide was followed by alkylation of dimethyl homoterephthalate to afford methyl 4‐amino‐4‐deoxy‐10‐carbomethoxy‐5,10‐dideazapteroate (14). Decarboxylation with ester cleavage (sodium cyanide in dimethyl sulfoxide at 180°) also gave the diaminopteroic acid (8).

5,10‐dideazaaminopterin (10) was an effective growth inhibitorof folate dependent bacteria, S. faecium and L. casei.
Synthesis of β‐D‐ribo‐ and 2′‐deoxy‐β‐D‐ribofuranosyl derivatives of 6‐aminopyrazolo[4,3‐c]pyridin‐4(5H)‐one by a ring closure of pyrazole nucleoside precursors
Authors: Gupta Pranab K. , Kent Dalley N. , Robins Roland K. , Revankar Ganapathi R.
Published: March 2009

6‐Amino‐1‐(2‐deoxy‐β‐D‐erthro‐pentofuranosyl)pyrazolo[4,3‐c]pyridin‐4(5H)‐one (5), as well as 2‐(β‐D‐ribofuranosyl)‐ and 2‐(2‐deoxy‐β‐D‐ribofuranosyl)‐ derivatives of 6‐aminopyrazolo[4,3‐c]pyridin‐4(5H)‐one (18 and 22, respectively) have been synthesized by a base‐catalyzed ring closure of pyrazole nucleoside precursors. Glycosylation of the sodium salt of methyl 3(5)‐cyanomethylpyrazole‐4‐carboxylate (6) with 1‐chloro‐2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranose (8) provided the corresponding N‐1 and N‐2 glycosyl derivatives (9 and 10, respectively). Debenzoylation of 9 and 10 with sodium methoxide gave deprotected nucleosides 14 and 16, respectively. Further ammonolysis of 14 and 16 afforded 5(or 3)‐cyanomethyl‐1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)pyrazole‐4‐carboxamide (15 and 17, respectively). Ring closure of 15 and 17 in the presence of sodium carbonate gave 5 and 22, respectively. By contrast, glycosylation of the sodium salt of 6 with 2,3,5‐tri‐O‐benzoyl‐D‐ribofuranosyl bromide (11) or the persilylated 6 with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose gave mainly the N‐2 glycosylated derivative 13, which on ammonolysis and ring closure furnished 18. Phosphorylation of 18 gave 6‐amino‐2‐β‐D‐ribofuranosylpyrazolo[4,3‐c]pyridin‐4(5H)‐one 5′‐phosphate (19). The site of glycosylation and the anomeric configuration of these nucleosides have been assigned on the basis of 1H nmr and uv spectral characteristics and by single‐crystal X‐ray analysis of 16.
Synthesis of some new 5‐chloro‐7‐mercapto‐1‐methyl/phenyl‐1,2,4‐triazolo[4,5‐b]pyrazin‐2(1H)‐ones and 5‐chloro‐3‐thiopyrazin‐2(1H)‐one derivatives as possible antibacterial and antifungal agents
Authors: Bhattacharya B. K.
Published: March 2009

Several new 5‐chloro‐7‐mercapto‐1‐methyl/phenyl‐1,2,4‐triazolo[4,5‐6]pyrazin‐2(1/H)‐ones V and their disul‐phides VI, 5‐chloro‐3‐mercapto‐2(1H)‐pyrazinonones III, 5‐chloro‐3‐(N‐aryl‐N‐acetylthioureido)‐1‐methyl/‐phenyl‐2(1H)‐pyrazinones VII, 5‐chloro‐1‐methyl/phenyl‐3‐sulphonamido‐2(1H)‐pyrazinones X and chloro‐2‐methyl/phenyl‐(3‐methyl)‐3‐thio‐2(1H)‐pyrazinones XI were synthesized starting from 3,5‐dichloro‐1‐methyl/phenylpyrazin‐2(1H)‐ones I. Fifteen of these compounds were screened for their antibacterial and antifungal activity against two bacteria B. subtilis and S. aureus, and two fungi A. niger and H. oryzae. A possible structure activity relationship is given.
Synthesis of pyridazino[1,6‐a]benzimidazoles
Authors: Benjamin Louis E. , Earley James V. , Gilman Norman W.
Published: March 2009

The synthesis of eight pyridazino[1,6‐a]benzimidazoles by a novel synthetic route is described. This relatively unexplored heterocyclic ring system is readily accessible starting from benzoylpropionic acids and phenylhydrazines in five steps. The interactions of these compounds with the benzodiazepine receptor are briefly mentioned.
Synthesis of pyridazino[4,5‐b]indole derivatives from 2‐(3‐carboxy‐1‐methylindole)acetic acid anhydride
Authors: Monge A. , Palop J. A. , Goñi T. , Fernández‐Alvarez E.
Published: March 2009

2‐(3‐Carboxy‐1‐methylindole)acetic acid anhydride (1) reacts with aryldiazonium salts to give 85–95% of the corresponding α‐hydrazono anhydrides 2. Treating 2 with boiling hydrazine hydrate in xylene, the respective 2‐aryl‐4‐carbohydrazido‐5‐methyl‐1‐oxo‐1,2‐dihydro‐5H/‐pyridazino[4,5‐b]indoles 3 were obtained (47–67%), and these compounds characterized as the respective benzylidene derivatives 4. Compounds 2 react with amines (aniline, morpholine, piperidine) to give the respective 2‐(3‐carboxy‐1‐methylindole)aceta‐mide 5 or the respective 2‐aryl‐4‐carboxamido‐5‐methyl‐5H‐pyridazino[4,5‐b]indole 6, the product obtained depending on the structure of the aryl substituent. Boiling 2b (aryl = 4‐chlorophenyl) with 5% sodium hydroxide gave (80%) 2‐(3‐carboxy‐1‐methylindole)acetic acid (7). Hydrolysis of 2b gave a mixture of 7 and 2‐(3‐carboxy‐1‐methylindolyl)‐2‐(4‐chlorophenylhydrazono)acetic acid (8).
The fragmentation of 7‐(o‐ and p‐R‐benzylidene)‐3‐(o‐ and p‐R‐phenyl)‐2‐methyl‐3,3a,4,5,6,7‐hexahydro‐2H‐indazoles under electron impact. II
Authors: Cortés E. , Martínez R. , Arzacoya E.
Published: March 2009

The electron impact mass spectrometric fragmentation pathways for several 2‐methylindazoles, II, were investigated. Our investigation of the mass spectra of these compounds revealed interesting relationships between the 2‐N‐methyl‐substituent in the framework of II and the fragmentation patterns.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (Isatoic Anhydride). 19. Direct formation of 2‐aminobenzyl alcohols from the reduction of N‐substituted isatoic anhydrides
Authors: Coppola Gary M.
Published: March 2009

Isatoic anhydrides 1 are easily reduced with sodium borohydride to o‐(substituted‐amino)benzyl alcohols 3 in good yield. Sequential reduction of N‐(2‐nitrobenzyl)isatoic anhydride (5) with sodium borohydride followed by catalytic hydrogenation of the nitro group affords the naturally occurring 2‐(2′‐aminobenzylamino)‐benzyl alcohol (4) in 72% yield.
A conveneint synthesis of 1‐substituted‐2,5(4H)‐piperazinediones
Authors: Lovelette C. A. , Geagan K.
Published: March 2009

1‐Substituted‐2,5(4H)‐piperazinediones are prepared by the Michael addition of acrylonitrile and methyl‐acrylate and glycylglycine, DL‐alanyl‐DL‐alanine and DL‐alanyl‐DL‐phenylalanine followed by cyclohydration in refluxing xylenes.
Synthesis of sulfur and nitrogen analogues of monooxo crown ethers
Authors: Matsushima Kenji , Nakatsuji Yohji , Kawamura Norio , Okahara Mitsuo
Published: March 2009

Sulfur or nitrogen analogues of monooxo crown ethers were prepared via intramolecular cyclization of the corresponding thia or aza oligoethylene glycol carboxylmethyl ethers by using benzenesulfonyl chloride in the presence of alkali metal carbonates.
Synthesis of ribonucleosides of 4(5)‐cyano‐5(4)‐methylimidazole and related 4‐substituted‐5‐methylimidazole ribosides
Authors: Andrés J. Ignacio , García‐Lopez M. Teresa
Published: March 2009

4‐Cyano‐1‐(2,3,5‐tri‐O‐acetyl‐β‐D‐ribofuranosyl)‐5‐methylimidazole (4) and its corresponding 5‐cyano‐4‐methyl substituted isomer (5) have been obtained by ribosylation of 4(5)‐cyano‐5(4)‐methylimidazole (3) via the mercuric cyanide method or by ribosylation of the trimethylsilyl derivative of 3. Treatment of 4 with methanolic ammonia, ammonium chloride in liquid ammonia and potassium hydrosulfide provided 4‐cyano‐1‐β‐D‐ribofuranosyl‐5‐methylimidazole (6), 1‐β‐D‐ribofuranosyl‐5‐methylimidazole‐4‐carboxamide (2) and 1‐β‐D‐ribofuranosyl‐5‐methylimidazole‐4‐thiocarboxamide (11) respectively. Reaction of 6 with hydroxylamine afforded the corresponding 4‐carboxamidoxime substituted nucleoside (13) which on catalytic reduction in the presence of ammonium chloride, was transformed into 1‐β‐D‐ribofuranosyl‐5‐methylimidazole‐4‐carboxamidine (14) as hydrochloride salt.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXXII . The synthesis of 2‐azathianthrene and selected analogs
Authors: Lam Wing W. , Martin Gary E. , Lynch Vincent M. , Simonsen Stanley H. , Lindsay Charles M. , Smith Keith
Published: March 2009

The synthesis of 2‐azathianthrene ([1,4]benzodithiino[2,3‐c]pyridine), the only remaining monoazathianthrene yet to be reported, is described. Attempts at the direct condensation of disubstituted pyridines with the dianion of 1,2‐dimercaptobenzene were generally unsuccessful requiring that the alternative condensation of the dianion with disubstituted pyridine 1‐oxides be employed. The title compound was characterized by physical means including 13C‐nmr spectroscopy. One analog, 4‐nitro‐2‐azathianthrene was also studied by X‐ray crystallographic means; the molecule crystallized with two molecules in the asymmetric unit P21/n, a = 20.712(3), b = 7.8109(13), c = 13.720(2)Å, β = 107.880(11)°, Z = 8, the data refined to a final R = 0.051 for 3061 reflections. Dihedral angles between the planes of the phenyl rings were 135.00(13) and 132.52(13)° for the two independent molecules contained in the crystal. Close nonbonded S ⃛O intramolecular contacts were observed in both molecules between the sulfur and nitro‐group oxygens. Both nitro groups are twisted out of the plane of the pyridine ring and are oriented at angles of 28.75 and 38.82° respectively.
Synthesis, 13C NMR spectrum and crystal structure of 10‐Phenylpyrido[3,2‐b][1,4]benzothiazine 5‐Oxide
Authors: Jovanovic Misa V. , Biehl Edward R. , De Meester Patrice , Chu Shirley S. C.
Published: March 2009

The compound 10‐phenylpyrido[3,2‐b][1,4]benzothiazine 5‐oxide, 1, has been obtained in nearly quantitative yield oxidation of 10‐phenylpyrido[3,2‐b][1,4]benzothiazine with oxygen in dioxane solution. The 13C nmr chemical shift assignments of 1 are reported. Its structure has been determined by X‐ray single crystal methods. The crystals of 1 are monoclinic, space group P21/n. There are four molecules in a unit‐cell of dimensions a = 12.347(3), b = 12.947(3), c = 8.987(1)Å, β = 106.73(1)° and V = 1375.8(5) Å3. The central ring is in a boat conformation and the sulfoxide oxygen atom occupies the axial position. The folding angle between the planes of the pyrido and the benzo planes is 161.55(9)°.
Addition de la proline à quelques alcènes et alcynes électrophiles
Authors: Yebdri Okacha , Texier Fernand
Published: March 2009

L'addition de la proline aux esters propiolique et phényl propiolique dans l'anhydride acétique conduit aux pyrroles isomères 5 et 6.

L'addition de la proline dans les mêmes conditions opératoires aux alcènes électrophiles pY‐PhCH = C(X) (CN) conduit à une pyrroline‐2 8 qui élimine HCN pour conduire au pyrrole 9. L'addition de la proline au fumarodinitrile est particulière, la réaction conduit à un mélange d'acide α‐aminé 10 et de composé 11. La structure de ce compose 11 est confirmée par diffraction RX.
Preparation of [23]cyclophane‐1,2‐diones by the reaction of 3,6;12,15‐Di‐1,4‐benzo[6.6](3,4)‐1,2,5‐thiadiazolocyclophanes with grignard reagents
Authors: Hatta Taizo , Mataka Shuntaro , Tashiro Masashi
Published: March 2009

3,6;12,15‐Di‐1,4‐benzo[6.6](3,4)‐1,2,5‐thiadiazolocyclophanes 1a‐c were prepared starting from 3,4‐di‐p‐tolyl‐1,2,5‐thiadiazole 3 and converted into [23]cyclophane‐1,2‐diones 2a‐c by the reaction with Grignard reagents.
Nucleophilic displacements of N‐aryl and heteroaryl groups. Part 8 . Intermolecular reactions of N‐aryl‐pyridinium, ‐quinolinium, and ‐acridinium salts with nucleophiles
Authors: Katritzky Alan R. , Wittmann Dieter K. , Chen Jen‐Luan , Marson Charles M. , Ossana Andrea
Published: March 2009

N‐Aryl‐mono‐, ‐tri‐ and ‐pentacyclic pyridinium cations react with S‐ and C‐nucleophiles to give: (i) simple addition of hydride at the α‐ring position, (ii) nucleophilic addition of thiophenoxide at the γ‐ring position, (iii) deprotonation at the 6‐position of a 5,6‐dihydroquinolinium ring followed by prototropic shift to give a 1,2‐dihydroquinoline derivative, (iv) ring contraction of a pyridine to a pyrrole ring, and (v) nucleophilic displacement of the N‐aryl group.
Synthesis of 6H,8H‐isoquino[2,3‐c][1,3]benzothiazin‐8‐ones
Authors: Fodor Lajos , Szabó János , Bernáth Gábor , Sohár Pál , Maclean David B. , Smith Richard W. , Ninomiya Ichiya , Naito Takeaki
Published: March 2009

6H,8H‐Isoquino‐1,3‐benzothiazin‐8‐ones have been prepared by reaction of 6,7‐dimethoxy‐2H‐1,3‐benzo‐thiazines with homophthalic anhydride and by photocyclization of 3‐benzoyl‐4‐methylene‐6,7‐dimethoxy 2H‐1,3‐benzothiazine. The compounds are thia analogues of protoberberine alkaloids containing a sulfur atom at C‐5 and a lactam function at C‐8. The mass spectra of the title compounds are discussed.
The syntheses of 4b,5a‐dihydro‐5H‐benzo[3,4]‐phenanthro[1,2‐b]azirine and 1a,11b‐dihydro‐6,11‐dimethyl‐1H‐benz[3,4]anthra[1,2‐b]azirine
Authors: Abu‐Shqara Elias , Blum Jochanan
Published: March 2009

The syntheses of the K‐imine derivatives of carcinogenic benzo[c]phenanthrene and 7,12‐dimethylbenz‐[a]anthracene are described. Treatment of trans‐5‐azido‐5,6‐dihydrobenzo[c]phenanthren‐6‐ol (3) and trans‐6‐azido‐5,6‐dihydrobenzo[c]phenanthren‐5‐ol (5) with thionyl chloride yielded the corresponding β‐chloro azides, which in turn, were reacted with lithium aluminium hydride to give 4b,5a‐dihydro‐5H‐benzo[3,4]‐phenanthro[1,2‐b]azirine (2). In a similar manner trans‐5‐azido‐5,6‐dihydro‐7,12‐dimethylbenz[a]anthracen‐6‐ol (11) and trans‐6‐azido‐5,6‐dihydro‐7,12‐dimethylbenz[a]anthracen‐5‐ol (13) were transformed to the respective chloro azides and, converted into 1a,11b‐dihydro‐6,11‐dimethyl‐1H‐benz[3,4]anthra[1,2‐b]azirine (10).
Synthesis of 1‐trifluoroacetyl‐3‐dialkylamino‐methyl‐5‐monosubstituted benzimidazoline‐2‐thiones using trifluoroacetic acid as an acylating agent
Authors: Joshi Krishna C. , Misra Ram A. , Jain Renuka , Sharma Kanti
Published: March 2009

1‐Trifluoroacetyl‐3‐dialkylaminomethyl‐5‐monosubstituted benzimidazoline‐2‐thiones have been synthesized from p‐substituted anilines which were acetylated with trifluoroacetic acid. The trifluoroacetanilides were nitrated, reduced and cyclised with carbon disulphide in the presence of alcoholic potassium hydroxide and finally treated with formaldehyde and suitable secondary amines to afford the Mannich bases. The compounds were characterised by their analytical and spectral (ir, pmr, 19F and mass) data. The synthesized compounds have been screened for anti‐inflammatory and analgesic activity and found to be active.
Investigation of the reactions of fluorine containing 3‐hydrazino‐5H‐1, 2, 4‐triazino[5, 6‐b]indoles with ethyl acetoacetate. Synthesis of some novel tetracyclic ring systems
Authors: Joshi Krishna C. , Dandia Anshu , Baweja Sunita
Published: March 2009

Novel tetracyclic ring systems viz. 3‐methyl‐1‐oxo‐12H‐1, 2, 4‐triazepino[3′,4′:3, 4][1, 2, 4]triazino[5, 6‐b]indole (4a) and 3‐methyl‐5‐oxo‐12H‐1, 2, 4‐triazepino[4′,3′:2, 3][1, 2, 4]triazino[5, 6‐b]indole (5a), having angular and linear structures respectively, were synthesized by the cyclization of 3‐oxobutanoic acid [5H‐1, 2, 4‐triazino‐[5, 6‐b]indole‐3‐yl]hydrazone (3a). However, cyclization of 3b (R = CHa, R1 = R2 = H) afforded the angular product 4b exclusively. Moreover, cyclization of 3c (R = R3 = H, R1 = F) yielded 7‐fluoro‐1‐0xo‐10H‐1, 3‐imidazo[2′,3′:3, 4][1, 2, 4]triazino[5, 6‐b]indole (6c) and 7‐fluoro‐3‐oxo‐10H‐1, 3‐imidazo[3′,2′:2, 3][1, 2, 4]triazino‐[5, 6‐b]indole (7c) instead of the expected triazepinone derivatives. Compound 3d (R = R1 = H, R2 = CF3) also gave an imidazole derivative but only one angular product was obtained. In all these reactions, formation of the angular product involving cyclization at N‐4 is favoured. Characterization of these products have been done by elemental analyses, ir, pmr, 19F nmr and mass spectral studies.
Site‐and regioselective π4S + π2S cycloaddition of nitrileoxides to pyridazin‐3‐ones: Formation of novel 3a, 7a‐dihydroisoxazolo[4, 5‐d]pyridazin‐4‐ones
Authors: Srinivasan T. N. , Sattur P. B. , Rao K. Rama , Prasad A. S. Bhanu , Jemmis E. D.
Published: March 2009

A study of the cycloaddition behaviour of substituted pyridazin‐3‐ones with arylnitrile oxides has been carried out, Nitrile oxides udergo site and regioselective 1, 3‐dipolar cycloaddition to 4, 5‐double bond of pyridazinone to afford 3a, 7a‐dihydroisoxazolo[4, 5‐d]pyridazin‐4‐ones. The reactions follow frontier orbital predictions. Nitrile oxide HOMO‐pyridazinone LUMO combination is dominant.
Synthèse de 5H‐isoquino[6, 7‐b][1, 6]naphtyridones‐12 substituées sur leur sommet 10
Authors: Rivalle Christian , Huel Christiane , Bisagni Emile
Published: March 2009

Deux chloro‐10‐5H‐isoquino[6, 7‐b][1, 6]naphtyridones‐12 ont été synthétisées au départ d'acides chloro‐4 nicotiniques et de l'amino‐6 méthyl‐5 2H‐isoquinolone‐1, cyclisation des acides intermédiaires par l'acide sul‐furique ou l'acide trifluorométhanesulfonique puis chloration par l'oxychlorure de phosphore.

La comparaison de la cytotoxicité des diéthylamino‐propylamino‐10 méthyl‐6‐H‐isoquino[6, 7‐b][1, 6]naphtyridones‐12‐obtenues par substitution des dérives chlorés‐ avec celle des aza‐9 ellipticines qui leur sont appar‐entées, montre que le remplacement du noyau pyrrole par un cycle pyridone‐4 entralne une perte d'activité biologique.
Hantzsch reaction of 3‐(2‐bromoacetyl)tropolone. Synthesis of 3‐(4‐thiazolyl)tropolones
Authors: Qian Chang‐Yi , Jin Zhong‐Tian , Yin Bing‐Zhu , Imafuku Kimiaki
Published: March 2009

3‐Acetyltropolone was brominated with phenyltrimethylammonium tribromide to afford 3‐(2‐bromoacetyl)‐tropolone (2), whose reactions with thiourea, thioformamide, and ammonium dithiocarbamate gave respectively 3‐(2‐amino‐4‐thiazolyl)‐, 3‐(4‐thiazolyl)‐, and 3‐(2‐mercapto‐4‐thiazolyl)tropolone. In a similar manner, compound 2 was treated with six 1‐substituted 2‐thioureas and three thioamides to give the corresponding 3‐(4‐thiazolyl)tropolone derivatives.
Carbamates, thiolcarbamates, dithiocarbamates and thioncarbamates derived from 2‐benzothiazolinone and benzoxazolinone
Authors: D'Amico John J. , Bellinger Frederic G.
Published: March 2009

The reaction of 3‐(2‐hydroxyethyl)‐2‐benzothiazoline with methyl, phenyl isocyanate, or dimethylcarbamoyl chloride afforded the carbamates 1–4. The carbanilate 5 was prepared by the reaction of 2‐benzothiazolinone with 3‐chloropropyl‐N‐methylcarbanilate under basic conditions. The reaction of the appropriate 2‐benzothiazolinone with the appropriate 2‐chloro or 3‐chloropropyl disubstituted thiolcarbamate under basic conditions furnished the thiolcarbamates 6–14. The thiolcarbamate 15 was prepared by the reaction of sodium di‐isopropylthiolcarbamate with 3‐(chloromethyl)‐2‐benzothiazolinone. The reaction of 3‐(chloromethyl)‐2‐ben‐zothiazolinone and related compound with the appropriate sodium or triethylamine salt of disubstituted dithiocarbamate afforded the dithiocarbamate 16–22. The reaction of the appropriate xanthate with the potassium salt of bromoacetic acid and the appropriate secondary amine afforded the thionocarbamates 23–29. The thionocarbamate 30 was synthesized by the reaction of 5‐chloro‐2‐benzothiazolinone with 3‐chloropropyl diethylthionocarbamate.
A selective synthesis of novel isoxazolo[2, 3‐a]‐quinoxalines and pyrrolo[1, 2‐a]quinoxalines
Authors: Kim Ho Sik , Kurasawa Yoshihisa , Takada Atsushi
Published: March 2009

The isoxazolo[2, 3‐a]quinoxalines 11a, b and pyrrolo[1, 2‐a]quinoxalines 12a, b were selectively synthesized from the 2‐substituted 6‐chloroquinoxaline 4‐oxides 10a, b. The pyrrolo[1, 2‐a]quinoxalines 12a, b were clarified to be produced by the ring transformation of the isoxazolo[2, 3‐a]quinoxalines 11a, b.
The reductive repair of 1, 3‐dhnethylthymine bromohydrin into 1, 3‐dimethylthymine by 1, 5‐dihydro‐5‐deazaflavin or 1, 4‐dihydroquinoline
Authors: Akiyama Taishin , Tanaka Kiyoshi , Yoneda Fumio
Published: March 2009

The reductive conversion of 1, 3‐dimethylthymine bromohydrin into 1, 3‐dimethylthymine by 10‐ethyl‐3‐methyl‐1, 5‐dihydro‐5‐deazaflavin or 1‐benzyl‐3‐carbamoyl‐1, 4‐dihydroquinoline has been achieved in the presence of trifluoroacetic acid.
A versatile route to potential dihydrofolate reductase inhibitors via the hitherto unknown 6‐benzyl‐2‐(O‐methyl)uracils: Synthesis of isotrimethoprim
Authors: Botta Maurizio , Artico Marino , Massa Silvio , Gambacorta Augusto
Published: March 2009

The synthesis of 2, 4‐diamino‐6‐(3, 4, 5‐trimethoxybenzyl)pyrimidine (isotrimethoprim) has been accomplished starting from 2‐(O‐methyl)‐6‐(3, 4, 5‐trimethoxybenzyl)uracil by standard procedures. The benzyluracil derivative has been obtained by reacting O‐methylisourea sulphate and ethyl 3, 4, 5‐trimethoxyphenacetylace‐tate.