bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and chemical reactivity of indenoisoxazoles
Authors: Lemke Thomas L. , Sawhney Kailash N. , Lemke B. Kaye 
Published: March 2009

AbstractTreatment of 2‐pivaloyl‐1,3‐indandione (1) with hydroxylamine under acidic conditions, results in formation of 8‐t‐butylindeno[1,2‐c]isoxazol‐7‐one (2) while treatment of the triketone with hydroxylamine at neutral or basic pH gave 6 which upon cyclization gave the isomeric 3‐t‐butylindeno[1,2‐c]isoxazol‐4‐one (7). Compound 7 was readily reduced to amine 12 by treatment with hydrazine or hydrogen over platinum. The amine, although quite unreactive, was converted to 3‐t‐butylindeno[1,2‐c]pyrazol‐4‐one (13) with hydrazine or reduced to 15 and 16 with sodium in liquid ammonia and alcohol. Surprisingly, the amine 3 obtained from isoxazole 2 gave reduction product 15 from a sodium‐liquid ammonia reduction and not the expected product 18. Spectral evidence for each of the structures is discussed.
On the reactivity of N‐benzylpyrimidinium salts with nitrogen nucleophiles
Authors: Dlugosz A. , van der Plas H. C. , Van Veldhuizen A. 
Published: March 2009

AbstractTreatment of the l‐benzyl salts of pyrimidine, 4,6‐dimethylpyrimidine, and 4‐t‐butylpyrimidine with liquid ammonia leads to debenzylation. The 1H‐nmr spectroscopic evidence is presented that the initial step in the debenzylation of l‐benzyl‐4,6‐dimethylpyrimidinium bromide is the addition of the ammonia at C‐2, while with l‐benzyl‐4‐t‐butylpyrimidinium bromide the addition takes place at C‐6. It is proved by 15N labelling that the debenzylation occurs according to the ANRORC mechanism. The above‐mentioned l‐benzylpyrimidinium bromides give with hydrazine, pyrazole, 3,5‐dimethylpyrazole and 3‐t‐butylpyrazole, respectively.
Synthesis of pyrido[3,4‐b]pyrano[3,4‐b]indoles
Authors: Freter Kurt , Fuchs Victor 
Published: March 2009

AbstractThe synthesis of some pyrido[3,4‐b]pyrano[3,4‐b]indoles (3) from 3‐hydroxy‐4‐(3‐indolyl)piperidines (6) is reported.
Oxidation of 4‐chromanones with thallium(III) nitrate
Authors: Ciattini Pier Giuseppe , Morera Enrico , Ortar Giorgio 
Published: March 2009

AbstractTreatment of 4‐chromanones 1a‐g with thallium(III) nitrate in acidic methanol results mainly in dehydrogenation, whereas α‐methoxylation and/or Taylor‐McKillop rearrangement predominate in trimethyl orthoformate. The mechanistic features of these oxidations are briefly discussed.
A comparative study of the rearrangement of some 6‐ and 7‐halo‐substituted 3‐amino‐3,4‐dihydro‐l‐hydroxycarbostyrils in concentrated hydrohalic acids
Authors: Mccord Tommy J. , Crawford Charles P. , Rabon James A. , Gage Larry D. , Winter J. Mark , Davis Alvie L. 
Published: March 2009

AbstractThe 6‐bromo (16), 6‐fluoro (17), 7‐bromo (14), and 7‐fluoro (15) substituted 3‐amino‐3,4‐dihydro‐l‐hydroxycarbostyrils were treated with concentrated hydrochloric and hydrobromic acids under reflux conditions. The 7‐halogenated N‐hydroxycarbostyrils (14,15) gave the normal rearrangement products, the 6,7‐dihalolactams (18–21). The 6‐halogenated compounds (16,17) yielded the corresponding 6,8‐dihalolactams (22–24) under the same experimental conditions, with the exception of the hydrobromic acid reaction of the 6‐fluoro derivative 17 which yielded a mixture of products. Based on the comparison of the nmr spectrum of the product mixture with those of two authentic compounds, the mixture was identified as consisting of the normal rearrangement product, the 8‐bromo‐6‐fluorolactam (27) and the straightforward reduction product, the 6‐fluorolactam (26) in a ratio of about 2:1. The latter compounds were prepared by an independent method of synthesis in which 2‐amino‐5‐fluorophenylalanine (25) was acidified to yield the corresponding lactam 26, followed by bromination to afford the 8‐bromo‐6‐fluorolactam 27. A mechanism is proposed to interpret the experimental results of nucleophilic substitution with rearrangement and reduction which occur with the 6‐fluoro compound 17 when exposed to bromide ions in strongly acidic solution.
Synthesis of some 5,10,15,20‐tetraalkylchlorin and tetraalkylporphyrin complexes of transition metals
Authors: Ulman Abraham , Fisher Diane , Ibers James A. 
Published: March 2009

AbstractMetal‐assisted template syntheses of 5,10,15,20‐tetraalkylchlorin and tetraalkylporphyrin complexes of transition metals are described. With Co only the porphyrins are obtained; with Cu only the chlorins; with Ni a mixture of chlorin and porphyrin is obtained depending on alkyl and added anhydride. As opposed to the higher alkyls, (5,10,15,20‐tetramethylporphyrinato)nickel(II) dimerizes in solution, a dimerization constant of 3.9 ± 1.3 M−1 being derived from 1H nmr data.
Heterocycles. Part I. A new route to the synthesis of substituted 2‐aminopyrimidines
Authors: El‐Rayyes N. R. 
Published: March 2009

AbstractHeterocyclic aldehydes (A) reacted with alkyl aryl ketones (B) to give the corresponding 1,3‐diaryl‐2‐propen‐1‐ones (Ia‐1). Condensation of these chalcones with guanidine produced the corresponding 2‐amino‐4,6‐diarylpyrimidines (IIa‐1). The structure of all products was substantiated by chemical and spectroscopic methods.
Synthése d'héterocycles. XX. Reaction du malononitrile avec quelques cinnamonitriles
Authors: Del Carmen Chacón María , Del Carmen Pardot María , Soto José Luis , Lorente Antonio , Fuentes Luis 
Published: March 2009

AbstractLa reaction de certains cinnamonitriles para‐substitués avec le malononitrile en milieu methanol‐methylate de sodium conduit aux dihydropyridines 5, dont l'aromatisation fournit les pyridines 6. Dans le cas du p‐nitrocinnamonitrile on obtient directement la pyridine 6d.
Synthesis of 3H‐pyrazol‐3‐one derivatives containing a 9H‐thioxanthene ring
Authors: Okabayashi Ichizo 
Published: March 2009

Abstract2,4‐Dihydro‐5‐methyl‐2‐phenyl‐4‐(9H‐thioxanthen‐9‐yl)‐3H‐pyrazol‐3‐one (3) was prepared by condensing 9H‐thioxanthen‐9‐ol (1) with 2,4‐dihydro‐5‐methyl‐2‐phenyl‐3H‐pyrazol‐3‐one (2), or by cyclizing ethyl α‐acetyl‐9H‐thioxanthene‐9‐acetate (4) with phenylhydrazine. 2,4‐Dihydro‐5‐methyl‐2‐phenyl‐4‐(9H‐thioxan‐ then‐9‐yl)‐3H‐pyrazol‐3‐one 10,10‐dioxide (8) was prepared by cyclizing ethyl α‐acetyl‐9H‐thioxanthene‐9‐acetate 10,10‐dioxide (7) with phenylhydrazine. Compound 8 was also obtained by oxidizing 3 with hydrogen peroxide in acetic acid. 5‐Amino‐2,4‐dihydro‐2‐phenyl‐4(9H‐thioxanthen‐9‐yl)‐3H‐pyrazol‐3‐one (10) was obtained by condensing 1 with 5‐amino‐2,4‐dihydro‐2‐phenyl‐3H‐pyrazol‐3‐one (9).
Synthesis of benzo[1,2]phenaleno[bc]thiophenes
Authors: Pratap Ram , Castle Raymond N. , Lee Milton L. 
Published: March 2009

AbstractThe synthesis of both isomers of benzo[1,2]phenaleno[bc]thiophene namely, benzo[1,2]phenaleno[3,4‐bc]‐thiophene and benzo[1,2]phenaleno[4,3‐bc]thiophene is described.
Electron impact mass spectrometry of 2,5‐bis(p‐R‐phenyl)thiophenes
Authors: Jiménez R. , Cortés E. 
Published: March 2009

AbstractThe mass spectra of a series of 2,5‐bis(p‐R‐phenyl)thiophenes are reported and discussed. The fragmentation patterns and mechanisms postulated have been confirmed by the determination of the metastable peaks. All the compounds possess the molecular ion as the base peak.
Conformational and configurational studies on 3‐azabicyclo[3.3.1]nonane (3‐abn) derivatives and related systems employing carbon‐13 NMR spectroscopy
Authors: Jeyaraman R. , Jawaharsingh Cooksley Baldwin , Avila S. , Ganapathy K. , Eliel Ernest L. , Manoharan Muthiah , Morris‐Natschke Susan , Kenan W. R. 
Published: March 2009

AbstractThe 13C nmr spectra of 4 cis‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonanes, 11 cis‐2,4‐diaryl‐3‐azabicyclo[3.3.1]‐nonan‐9‐ones, 26 cis‐2,4‐diaryl‐3‐azabicyclo[3.3.1]‐nonan‐9‐ols or acetates thereof, 5 cis‐2,4‐diaryl‐3‐azabi‐cyclo[4.3.1]decan‐10‐ones or ‐10‐ols and 5 cis‐2,4‐diphenyl‐3‐aza‐7‐thiabicyclo[3.3.1]nonan‐9‐ones, ‐9‐ols or 9‐yl acetates have been recorded. Except for the 7‐thia compounds, which appear to exist mainly in the configuration and conformation with the nitrogen‐containing ring in the boat form, these compounds seem to exist overwhelmingly in chair‐chair conformations. The configuration of the 9‐ols and their acetates (syn or anti to the nitrogen‐containing ring) has been deduced from the spectra. In a number of cases, the structures assigned differ from those earlier postulated. Broadening of one set of aryl signals (probably those due to the ortho carbons) in the case of N‐methyl (but not N‐H) compounds without ortho substituents is ascribed to restricted phenyl rotation.
Alkylation en catalyse par transfert de phase d'une série d'acridanone‐9 substituées: Compétition entre O‐ et N‐alkylation
Authors: Mahamoud Abdallah , Galy Jean‐Pierre , Vincent Emile‐Jean , Galy Anne‐Marie , Barbe Jacques 
Published: March 2009

AbstractL'alkylation en catalyse par transfert de phase d'une série d'acridanones diversement substituées conduit a un mélange d'isomeres O‐ et N‐alkyles. Contrairement au substituant, l'agent alkylant a un rǒle essentiel dans l'orientation de la reaction. Celle‐ci peut, d'ailleurs, ětre interprétee a l'aide du principe HSAB.
Photoaddition of carbonyl compounds to five‐membered ring heterocycles
Authors: Rivas C. , Bolivar R. A. , Cucarella M. 
Published: March 2009

AbstractIt has been possible to prepare oxetanes from several carbonyl compounds and derivatives of furan, pyrrole and thiophene. This account summarizes the successful and some of the unsuccessful attempts carried out in this laboratory to extend the Paterno‐Büchi reaction to the common five‐membered heterocyclic systems; the new compounds obtained in this connection are reported and several interesting facts which may help understand the reactivity of heterocycles in the presence of excited carbonyl compounds are commented.
Synthesis of 2‐(5′‐substituted isoxazol‐3′‐yl)‐4‐oxo‐3‐thiazolidinylalkanoic acids
Authors: Baraldi P. G. , Simoni D. , Moroder F. , Manfredini S. , Mucchi L. , Dalla Vecchia F. , Orsolini P. 
Published: March 2009

AbstractA series of 2‐substituted 4‐oxo‐3‐thiazolidinylalkanoic acids bearing an isoxazole nucleus in the 2‐position have been prepared. None of the compounds synthesised showed antibacterial activity in vitro.
Synthesis of pyrido[1,2‐a]benzimidazoles by cyclizative condensation of 2‐halopyridines and 1,2‐benzenediamines. Scope and mechanism of the reaction
Authors: Sundberg Richard J. , Ellis James E. 
Published: March 2009

AbstractThe scope and mechanism of acid‐catalyzed cyclizative condensation of 2‐halopyridines with 1,2‐benzene‐diamines has been explored. The reaction requires a 2‐halopyridine which is activated toward nucleophilic substitution. Evidence in favor of a mechanism involving pyridine ring opening is presented. Of three substituted 1,2‐benzenediamines which were examined, the 4‐nitro compound gave a single cyclization product whereas 4‐chloro and 4‐methy 1‐derivatives gave isomeric mixtures. The structure of the product from 2‐chloro‐5‐nitropyridine and 4‐nitro‐1,2‐benzenediamine is shown to be 2,8‐dinitropyrido[1,2‐a]benz‐imidazole.
Synthesis of some new bicyclic pyrazoline derivatives
Authors: Khalaf Ali Ali , El‐Shafei Ahmed Kamal , El‐Sayed Ahmed Mahmoud 
Published: March 2009

Abstract2,6‐Diarylidenecyclohexanones react with hydrazine to give the corresponding bicyclic pyrazolines. The synthesis of a series of twenty eight substituted pyrazolines is described. The structure of all products was confirmed by microanalyses, ir and nmr data.
Heterocycles from phosphonium salts: A facile method for modification of the 4(5)‐methyl group of thiazoles
Authors: Lee Webb R. , Lam Bing L. , Lewis Joseph J. , Wellman George R. , Berkoff Charles E. 
Published: March 2009

AbstractThiazolyl phosphonium salts, formed from the condensation of acyl vinyl phosphonium salts with thioamides and thiourea, are readily functionaitzed in high yield. The sequence represents a useful general synthesis of multifunctional thiazoles.
Functional derivatives of thiophene. II. Synthesis and 1H‐NMR spectra of 1‐[2′‐(5′‐nitrothienyl)]pyrazoles
Authors: Gálvez C. , García F. 
Published: March 2009

AbstractThe preparation of 5‐methyl‐3,5‐dimethyl‐ and 3,4,5‐trimethyl‐l[2′‐(5′‐nitrothienyl)]pyrazoles from thienylhydrazines are described. The 1H‐nmr spectra of these compounds are discussed.
Synthesis and spectral studies of 2‐mercaptobenzimidazole derivatives. I
Authors: Saxena D. B. , Khajuria R. K. , Suri O. P. 
Published: March 2009

AbstractThe syntheses of some 2‐mercaptobenzimidazole (I) derivatives have been described. While preparing such compounds it has been observed that I reacts predominantly as the thione under anhydrous reaction conditions, and as the thiol in the presence of an alkali. Strutures of all of the nine compounds have been established with the help of spectral methods including 13C nmr spectroscopy of the two compounds (II and III).
Studies on the synthesis of heterocyclic compounds. Part VIII. A facile synthesis of new pyrazolo[3,4‐b]benzazepine‐4,9‐diones
Authors: Daidone Giuseppe , Plescia Salvatore 
Published: March 2009

Abstract2‐Carbomethoxybenzoyl chloride reacted with some 5‐methylamino‐l‐phenyl‐3‐R‐pyrazoles to yield N‐methyl‐l‐phenyl‐3‐R‐pyrazol‐5‐yl)‐2‐carbomethoxybenzamides. These products were readily transformed into the corresponding acid, which in turn, refluxed in phosphorus oxychloride afforded the tricyclic system, l‐phenyl‐3‐R‐pyrazolo[3,4‐b]benzazepine‐4,9‐dione.
Nitrile oxide cycloaddition routes to 2‐(isoxazolyl)‐benzoates and 2‐(1,2,4‐oxadiazol‐3‐yl)benzoates
Authors: Howe Robert K. , Schleppnik Frances M. 
Published: March 2009

AbstractCycloaddition of aromatic nitrile oxides to methyl o‐vinylbenzoate produced methyl 2‐(3‐aryl‐2‐isoxazolin‐5‐yl)benzoates; the isoxazolines were converted to methyl 2‐(3‐arylisoxazol‐5‐yl)benzoates. Reaction of the nitrile oxide from o‐methoxycarbonylbenzohydroximinoyl chloride (11) with phenylacetylene, styrenes, and aromatic nitriles resulted in methyl 2‐(5‐phenylisoxazol‐3‐yl)benzoate, methyl 2‐(5‐aryl‐2‐isoxazolin‐3‐yl)‐benzoates (15), and methyl 2‐(5‐aryl‐1,2,4‐oxadiazol‐3‐yl)benzoates, respectively. The isoxazolines 15 were converted to the corresponding isoxazoles 16.
Synthesis of 8‐amino‐6‐methoxycinnoline. A precursor for 2‐azaprimaquine
Authors: Coburn Robert A. , Gala Dinesh 
Published: March 2009

Abstract4‐Methoxy‐2‐nitroaniline was converted in seven steps to 8‐amino‐6‐methoxycinnoline with an overall yield of 33%. Several attempts to introduce a 5‐aminopentan‐2‐yl side‐chain in the amino‐group to give 2‐azaprimaquine were unsuccessful.
Solvent effects on the tautomerism of t‐butyl 2‐picolyl and t‐butyl quinaldyl ketones
Authors: Roussel R. , DeGuerrero M. Oteyza , Spegt P. , Galin J. C. 
Published: March 2009

AbstractThe tautomeric equilibria (constant Kτ) of tbutyl 2‐picolyl ketone (ketone ⇋ enol) and of tbutyl quinaldyl ketone (ketone ⇋ enamine) in semi‐dilute solution (0.3 mole.l−1) were studied by 1H‐nmr and uv spectroscopy as a function of solvent polarity, for a set of twenty‐five different solvents including apolar, dipolar aprotic as well as amphiprotic ones. The contribution of electrostatic field effects (π*), of solute‐solvent hydrogen bonding interactions (α) and of solvent cavitation effects (δh) were estimated separately and critically discussed, using multiparametric regression analysis and empirical polarity parameters, according to the “Solvatochromic Comparison Method” developed by Taft, et al. For both heterocyclic ketones, the hydrogen bond donor power of the solvent (α) is the major factor of the Kτ variations, as a result of preferential solvation of the ketonic tautomer.
Preparation of 7‐aminoquinolines as candidate antiparasitic agents
Authors: Markovac Anica , Wu Geng‐Shuen , Lamontagne Maurice P. , Blumbergs Peter , Meng‐Sheng Ao 
Published: March 2009

AbstractA series of ten 7‐quinolinediamines were prepared and evaluated for potential antiparasitic activity against P. berghei, P. cynomolgi, L. donovani and T. rhodesiense. Compounds 1d and 8 showed activity being slightly effective against L. donovani in hamsters.
Syntheses of fluorescent dyes. XIV. Standards for fluorescence measurements in the near neutral pH‐range
Authors: Wolfbeis Otto S. , Urbano Edmund 
Published: March 2009

AbstractHighly fluorescent cationic indicators have been obtained by reaction of heterocyclic nitrogen bases with 1,3‐propane sultone. Unlike the bases themselves, the fluorescence intensity of the cationic salts is practically pH‐independent in the neutral pH‐range, which makes them useful reference substances in measuring fluorescence intensities in physiological studies. Furthermore, they are sufficiently water soluble, the fluorescence maxima covering the wavelength range from 440 to 530 nm. 2‐(3‐Sulfonatopropyl)harmanium, (5) appears to be the most useful compound for intra‐ and extracellular liquids, since its fluorescence is not quenched by chloride ion.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXII. 6,7,9‐trimethyl‐4‐azaphenoxathiin: First reported synthesis of an analog of the 4‐azaphenoxathiin ring system
Authors: Puig‐Torres Salvador , Martin Gary E. , Smith Keith , Cacioli Paul , Reiss James A. 
Published: March 2009

AbstractThe reaction of 2‐chloro‐3‐thiocyanatopyridine with a substituted spiroepoxycyclohexadienone, which served as a masked phenol with reversed polarity, led to the first reported synthesis of an analog of the 4‐azaphenoxathiin ring system. Confirmation of the structure was obtained from the assignment of the 13C‐nmr spectrum.
Skeletal rearrangement of 3‐methoxy‐N‐chloromorphinan
Authors: Mohacsi E. , Hayes T. 
Published: March 2009

Abstract3‐Methoxymorphinan (1) was converted to the corresponding N‐chloro derivative 2 by treatment with aqueous sodium hypochlorite. Upon exposure to methanolic silver nitrate, 2 was rearranged to the carbinolamine ether 3. In addition, considerable amounts of the dechlorinated morphinan 1 were formed. The structure of 3 was secured by spectral analysis and its degradation to the hexahydroindoline derivative 4. The observed skeletal rearrangement of 2 which requires the migration of an alkyl group is discussed in terms of a nitrenium ion.
Synthesis of thieno[2,3‐e]‐1,2,4‐triazines
Authors: Ibrahim Yehia A. , Abdel‐Hady S. A. L. , Badawy M. A. , Ghazala M. A. H. 
Published: March 2009

Abstract3‐Methylmercapto‐5‐oxo‐6‐vinyl‐ and 2‐methyl‐3‐mercapto‐5‐oxo‐6‐vinyl‐2,5‐dihydro‐1,2,4‐triazines were readily converted into the corresponding thieno[2,3‐e]‐1,2,4‐triazine in one step by the action of phosphorus pentasulfide in pyridine. 4‐Methyl‐3‐mercapto‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazine is only converted into the 5‐thioxo analog and no thiophene ring product was obtained under the same conditions. Thieno[2,3‐e]‐1,2,4‐triazines were also more efficiently obtained by the action of phosphorus petnasulfide in pyridine on the appropriate 6‐acylmethyl‐3‐mercapto‐5‐oxo‐2,5‐dihydro‐1,2,4‐triazine.
Structure of the bromination product of 2‐ethyl‐1,4‐benzothiazin‐3(4H)‐one
Authors: Bates Robert B. , Duguay Laurent M. , Klenck Robert E. , Kriek George R. , Tempesta Michael S. , Brewer Arthur D. 
Published: March 2009

Abstract2‐Ethyl‐1,4‐benzothiazin‐3(4H)‐one and bromine react smoothly to give Z‐2‐(1‐bromoethylidine)‐2(H)‐1,4‐benzothiazin‐3(4H)‐one, which results from a complex bromination‐oxidation sequence. The structure of this product was determined by an X‐ray study.
Synthesis of some 10‐alkyl‐5‐deazaflavins and their use in the oxidation of benzyl alcohol and benzylamine
Authors: Kuroda Kazunori , Nagamatus Tomohisa , Sakuma Yoshiharu , Yoneda Fumio 
Published: March 2009

AbstractA series of 3‐methyl‐ and 3‐phenyl‐10‐alkyl‐5‐deazaflavins were synthesized in order to examine whether the length of 10‐alkyl‐substituents influences the oxidizing power.
The chemistry of carbazoles. X. Structure of a pentamethylcarbazole isolated from a kuwait mineral oil. An application of the UV spectral additivity
Authors: Tsunashima Yutaka , Sugimoto Tokunori , Kuroki Masatane 
Published: March 2009

AbstractThe structure of Carruthers' pentamethylcarbazole isolated from Kuwait mineral oil was determined. From the reported spectral data, we deduced methyl‐substitutions at the 1‐, 2‐, 4‐, 6‐ and 8‐positions and this was confirmed by synthesis. This is a good example demonstrating the usefulness of uv spectral additivity.
Note sur le mécanisme réactionnel de la transposition de Dimroth. Une étudeab initio
Authors: Nguyen Mint Tho , Leroy Georges , Sana Michel , Elguero José 
Published: March 2009

AbstractUne étudeab initiode la transposition de Dimroth de l'amino‐5 tétrazole‐1,2,3,4 conduit è la conclusion qu'en phase vapeur l'étape déterminante de la vitesse n'est pas l'isomérie cycle‐chaîne, mais soit l'isomérie Z‐E de la double liaison CN, soit la migration sigmatropique‐1,3 du proton.
Synthesis of some 8‐substituted 5‐deazaflavins
Authors: Yoneda Fumio , Mori Kenya , Sakuma Yoshiharu , Koshiro Akira 
Published: March 2009

AbstractTreatment of 8‐fluoro‐3,10‐dimethyl‐5‐deazaflavin (Ia) with ethyl cyanoacetate in ethanol in the presence of potassium carbonate gave the corresponding 8‐(1‐cyano‐1‐ethoxycarbonylmethyl)‐5‐deazaflavin, which was converted into 3,8,10‐trimethyl‐5‐deazaflavin by refluxing in aqueous dimethylformamide. Treatment of Ia with sodium azide in ethanol yielded 8‐azido‐3,10‐dimethyl‐5‐deazaflavin (V). Compound V was converted into the corresponding 8‐amino‐, 8‐acetamido‐, and 8‐benzamido‐5‐deazaflavins by heating in high boiling alcohols, acetic anhydride, and benzoic anhydride, respectively. Fusion of compound V with dimethyl acetylenedicarboxylate yielded 4,5‐bis(methoxycarbonyl)‐1‐(3,10‐dimethyl‐5‐deazaflavin‐8‐yl)‐1,2,3‐triazole.
Imino‐bridged heterocycles. I. A derivative of benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine
Authors: Halczenko W. , Shepard K. L. 
Published: March 2009

AbstractThe current interest in structures that contain a tricyclic framework with a nitrogen bridged central ring has prompted us to examine the synthesis of imino‐bridged benzocycloheptapyridines. Treatment of 5,6‐trans‐dibromobenzo[5,6]cyclohepta[1,2‐b]pyridin‐11‐one with anhydrous methyl amine in THF produced 6‐β‐bromo‐5,6‐dihydro‐11α‐hydroxy‐12‐methyl‐11H‐benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine, the first example of the desired bridged derivatives.
Synthèse deN‐2 alkyl (aryl) dioxo‐3,5 oxadiazolidine‐1,2,4
Authors: Kraus Jean‐Louis , Dugenet Philippe , Yaouanc Jean‐Jacques 
Published: March 2009

AbstractLa synthèse de nouveaux dérivésN‐2 alkyl (aryl) dioxo‐3,5 oxadiazolidine‐1,2,4 bioisostères de composés biologiquement actifs a été étudiée. La méthode de synthèse décrite, qui utilise des dérivés nitrés comme produit de départ et une base non‐aqueuse lors de l'étape de cyclisation, permet d'obtenir avec de bons rendements les composés alkylés ou arylés en positionN‐2.
Preparation of 3‐Amino‐1,2,4‐benzothiadiazine 1‐Oxides
Authors: Ross Donn D. , Lednicer Daniel 
Published: March 2009

AbstractA series of 3‐amino‐1,2,4‐benzothiadiazine 1‐oxides were obtained from the corresponding 3‐thiomethyl ethers by displacement with a series of amines; examples of the last included variously substituted piperazines and piperidines.
Halogenated ketenes. 37. The synthesis of pyranones utilizing the (4 + 2) cycloaddition of ketenes and siloxy dienes
Authors: Brady William T. , Agho Michael O. 
Published: March 2009

AbstractThe reaction of diphenyl‐, dichloro‐, and chloroketenes with several siloxy dienes results in (4 + 2) and/or (2 + 2) cycloaddition products depending primarily on Substitution in the diene. The (4 + 2) cycloaddition products are easily hydrolyzed to pyranones. These results are discussed in terms of a dipolar intermediate.