bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substituent effects in heterocyclic systems. 1H‐NMR Study of methyl 3,5‐diarylisoxazolium iodides
Authors: Baumstark Alfons L. , Dunams Tambra 
Published: March 2009

AbstractMethyl 3‐aryl‐5‐phenylisoxazolium iodides (I) and methyl 3‐phenyl‐5‐arylisoxazolium iodides (II) were synthesized from the corresponding isoxazoles in moderate yields. The 1H‐nmr chemical shifts for H‐4, series I and II, and the quaternary methyl group series II were found to correlate with values. The rho value observed for H‐4 series II was 3.3 times that observed in series I. The correlation observed in series I contrasts with the lack of (poor) correlations reported in the corresponding isoxazole and chalcone systems. The rho value observed in the correlation of the quaternary methyl group series II correlates well with an estimate based on methyl pyridinium salt data. The chemical shifts of the quaternary methyl group series I showed little or no variation. Swain‐Lupton and DSP treatments did not show improved correlations over the single parameter results. However, interpretation of these treatments reveals that similar processes are occuring in all three cases. The results for H‐4 series I showed that the reduction of transmission of the substituent effect in series I compared to that in series II was essentially due to equal reduction of both inductive and resonance effects. The mechanism of transmission seems to differ only in degree and not type.
Base‐induced cycloaddition of N‐(tosylmethyl)imino compounds to michael acceptors. Synthesis of 2,3,4‐trisubstituted pyrroles
Authors: Houwing Hendrik A. , Van Leusen Albert M. 
Published: March 2009

AbstractA series of N‐(tosylmethyl)imino compounds [TosCH2NC(L)A] has been prepared, and applied to a new, base‐induced, one‐operational synthesis of otherwise more difficultly accessible 2,3,4‐trisubstituted pyrroles from electron deficient olefins. This regiospecific process probably is an 1,3‐anionic cycloaddition, combined with the elimination of sulfinic acid and a leaving group L. The group A is retained as the 2‐substituent of the resulting pyrroles.
Monoamine oxidase and succinate dehydrogenase inhibitory properties of substituted mercaptoquinazolones
Authors: Mehrotra Suman , Barthwal J. P. , Saxena A. K. , Bhargava K. P. , Parmar S. S. 
Published: March 2009

AbstractTwelve 6‐substituted‐2‐(1′‐mercaptoacetyl‐3′‐arylurea)‐3‐phenyl‐4‐quinazolones were synthesized by condensation of 6‐substituted anthranilic acids and aryl isothiocyanates followed by reaction with chloroacetyl arylurea. These compounds were characterized by their sharp melting points and elemental analyses. All compounds were evaluated for their enzyme inhibitory activity. It was found that all substituted quinazolones at a final concentration of 2 × 10−4Minhibitedin vitromonoamine oxidase and succinate dehydrogenase activity of rat brain homogenates and the degree of inhibition ranged from 11–77% and 25–53%, respectively.
Chemistry of the phenoxathiins and isosterically related heterocycles. XVIII. The synthesis, 1H‐ and 13C‐NMR Spectroscopy of benzo[b]‐1,4,9‐triazaphenoxathiin
Authors: Turley James C. , Martin Gary E. , Inners Ruth R. 
Published: March 2009

AbstractThe first synthesis of a triazaphenoxathiin system, benzo[b]‐1,4,9‐triazaphenoxathiin, is reported. Attempts directed toward the total assignment of the 13C‐nmr spectrum of the title compound failed to produce an unequivocal assignment. The carbons of the benzo‐portion of the molecule could not be unequivocally assigned at 25.2 MHz but were subgrouped into permutable pairs of resonances on the basis of relaxation times, a result of the antisotropic reorientation of the molecule. Further attempts to complete the 13C‐nmr assignment at 100 MHz by selective on‐resonance decouplings in the 400 MHz 1H‐nmr spectrum were also unsuccessful because of similarities in the chemical shifts of the benzo‐protons. Complete 1H‐nmr chemical shifts and homo‐nuclear spin‐coupling constants were obtained using the PANIC program.
Heterocycles from N‐benzoylthioamides and dinucleophilic reagents
Authors: Whitfield Lawrence L. , Papadopoulos Eleftherios P. 
Published: March 2009

AbstractN‐Benzoylthioamides (1) react with hydrazines and hydroxylamine to form 1H‐1,2,4‐triazoles and 1,2,4‐oxadiazoles, respectively. A similar treatment of the S‐methyl derivatives of 1 with amidines leads to 1,3,5‐triazines. Ethyl ZV‐benzoylthiocarbamate undergoes analogous reactions to yield the corresponding ethoxyheterocycles.
Bleomycin analogs. Synthesis and proton nmr spectral assignments of thiazole amides related to bleomycin a2
Authors: Riordan James M. , Sakai Ted T. 
Published: March 2009

AbstractThe synthesis of a series of 2‐substituted thiazole‐4‐carboxamides of 3‐aminopropyldimethylsulfonium chloride is described and the proton nmr spectral assignments of these derivatives are made. The compounds, which are fragments and analogs of the DNA‐binding portion of the antitumor antibiotic bleomycin A2, will serve as probes of structure‐activity relationships in this family of drugs.
Condensation of 3‐methylbenzoxazolinone with α,β‐unsaturated acids
Authors: Merdji B. , Lesieur D. , Lespagnol C. , Barbry D. , Couturier D. 
Published: March 2009

AbstractThe reaction between 3‐methylbenzoxazolinone and some unsaturated acids in PPA leads to mixtures of compounds, depending on the acid: 6‐crotonyl‐ (or cinnamoyl)‐3‐methylbenzoxazolinones, 2,3‐dihydro‐2,5‐(or 2,7)dioxo‐3‐methylcyclopenta[f]benzoxazoles and 6‐(3‐oxo‐indanyl)‐3‐methylbenzoxazolinones. The structure of the products was established by 13C and 1H nmr spectroscopy and (or) by independent synthesis. Possible mechanisms of the reaction are discussed; when competition is possible as in the last step of the cyclization, the benzene ring shows a higher reactivity than the aromatic nucleus of the benzoxazolinone; the contrary is observed when the benzene ring is p‐chloro‐substituted.
Formation of pyrrole derivatives through aminolysis of 2‐azetidinone derivatives
Authors: Kano Shinzo , Shibuya Shiroshi , Ebata Tsutomu 
Published: March 2009

AbstractA mixture of 3‐(α,β‐epoxyisopropyl)‐1‐phenyl‐2‐azetidinone and benzylamine was heated in a sealed tube at 120–130° yielding 4‐anilinomethyl‐1‐benzyl‐3‐hydroxy‐3‐methyl‐2‐pyrrolidinone as a mixture of diastereoisomers. By this method, 4‐anilinomethyl‐3‐hydroxy‐3‐methyl‐1‐phenyl‐2‐pyrrolidinone and 4‐anilinomethyl‐3‐hydroxy‐3‐methyl‐1‐(3,4‐dimethoxyphenethyl)‐2‐pyrrolidinone were obtained by using aniline and 3,4‐dimethoxyphenethylamine, respectively, instead of benzylamine. The reaction of 4‐formyl‐1‐phenyl‐2‐azetidinone with 3,4‐dimethoxyphenethylamine afforded 4‐anilino‐1‐(3,4‐dimethoxyphenethyl)‐2,3‐dihydro‐2‐oxopyrrole. In a similar fashion, the 1‐n‐butyl and 1‐isobutyl analogues were obtained by the use of n‐butylamine and isobutylamine, respectively, instead of 3,4‐dimethoxyphenethylamine.
Studies on furan derivatives. XII. Nucleophilic substitution of methyl 5‐nitro‐2‐furancarboxylate. Preparation of methyl 5‐phenoxy‐2‐furancarboxylates
Authors: Tanaka Akira , Usui Toshinao , Shimadzu Masaji 
Published: March 2009

AbstractTwenty one methyl 5‐phenoxy‐2‐furancarboxylates prepared from the reaction of methyl 5‐nitro‐2‐furan‐carboxylate with phenoxides via displacement of the nitro group. In the reaction of potassium 2‐nitrophen‐oxide with methyl 5‐nitro‐2‐furancarboxylate at 110°‐120°, 2,2′‐dinitrodiphenyl ether was obtained as a main product.
Photochemical reactions of 6‐alkylamino‐ and 6‐alkylanilino‐5H‐benzo[a]phenothiazin‐5‐ones
Authors: Ueno Yoshio , Koshitani Jinya , Yoshida Takatoshi 
Published: March 2009

AbstractPhotochemical reactions of 6‐alkylamino‐ and 6‐alkylanilino‐5H‐benzo[a]phenothiazin‐5‐ones have been investigated. 6‐Ethylamino‐ and 6‐isopropylamino‐5H‐benzo[a]phenothiazin‐5‐ones and 6‐methylanilino‐ and 6‐ethylanilino‐5H‐benzo[a]phenothiazin‐5‐ones gave 6‐amino‐5H‐benzo[a]phenothiazin‐5‐one and 6‐anilino‐5H‐benzo[a]phenothiazin‐5‐one, respectively, on irradiation.
Preparation of 3‐methyl‐4‐vinyl‐1,2,5‐oxadiazole and 3‐methyl‐4‐vinyl‐1,2,5‐thiadiazole
Authors: Boger Dale L. , Brotherton Christine E. 
Published: March 2009

AbstractShort and high yielding preparations of 3‐Methyl‐4‐vinyl‐1,2,5‐oxadiazole (6a) and 3‐Methyl‐4‐vinyl‐1,2,5‐thiadiazole (6b) are described.
Synthesis of (±)‐O‐methylcannabichromene and some homologues
Authors: De La Torre M. , García F. , Cruz R. 
Published: March 2009

AbstractA facile novel synthesis of (±)‐O‐methylcannabichromene (5d) together with (±)‐2‐methyl‐2‐(4‐methyl‐3‐pentenyl)‐5‐methoxy‐2H‐benzopyran (5a) and its 7‐methyl (5b) and 7‐propyl (5c) homologues, using organolithium salts is described.
Improved synthesis of 3‐aralkylidine‐5‐arylthiophen‐2‐(3H)ones
Authors: Miller Gerald A. , Heindel Ned D. , Minatelli John A. 
Published: March 2009

Abstract3‐Aralkylidene‐5‐arylthiophen‐2‐(3H)ones can be prepared in two steps from 4‐aryl‐4‐oxobutanoic acids through the intermediacy of butenolides and thiophenones generated by the sequential action of acetic anhydride, sodium hydrosulfide and aromatic aldehydes.
Synthesis of some 2‐amino‐4‐phenyl‐3H‐1,5‐benzodiazepines by reaction of aromatic diamines and acetylenic imidates
Authors: Unangst Paul C. 
Published: March 2009

AbstractThe reaction of several aromatic 1,2‐diamines with conjugated acetylenic imidate salts is described. The use of hexamethylphosphoric triamide (HMPA) as the solvent allows preparation of 2‐amino‐4‐phenyl‐3H‐1,5‐benzodiazepines in a one‐step reaction.
Thiophene systems. 6. An unexpected bromine migration during the synthesis of thieno[3,4‐b][1,5]benzoxazepin‐10‐ones
Authors: Press Jeffery B. , Eudy Nancy H. 
Published: March 2009

Abstract7‐Bromothieno[3,4‐b][1,5]benzoxazepin‐10‐one (1a) was unexpectedly formed upon acid catalyzed ring closure of 5‐bromo‐4‐ethoxy‐2′‐hydroxy‐3‐thiophenecarboxanilide (2a). Ring closure of the chlorine analogue 2c proceeded normally to give 3‐chlorothieno[3,4‐b][1,5]benzoxazepin‐10‐one (1b).
An easy and efficient synthesis of 4H‐thiazolo[5,4,3‐ij]quinolin‐4‐ones and 5H‐1,4‐thiazino[2,3,4‐i,j]quinolin‐5‐ones
Authors: Babudri Francesco , Di Nunno Leonardo , Florio Saverio 
Published: March 2009

AbstractThe title heterocycles have been synthesized by a Claisen‐type self condensation of acetylbenzothiazolines and acetyldihydrobenzothiazines and subsequent cyclization.
One‐Pot synthesis of substituted pyrrolidines via aminomercuration‐demercuration of 1,4‐ and 1,5‐Hexadiene
Authors: Barluenga J. , Najera C. , Yus M. 
Published: March 2009

AbstractThe aminomercuration‐demercuration of 1,4‐ and 1,5‐hexadiene yield cis‐ and trans‐2,5‐dimethyl‐N‐arylpyrrolidines via one‐pot process. The intermolecular cyclization reaction goes through the corresponding mercurated pyrrolidines; these intermediates were isolated and characterized when the mercuration reaction was completed. The high stereoselectivity observed allows an easy way of synthesis for N‐substituted trans‐2,5‐dimethylpyrrolidines.
Selenium‐sulfur analogs. Mass spectrometric comparison of substituted selenazoles and thiazoles
Authors: Jham G. N. , Vouros Paul , Hanson R. N. , Giese R. W. 
Published: March 2009

AbstractThe electron impact mass spectra of a series of thiazoles and selenazoles were compared. No major differences in the mass spectral behavior between the sulfur and selenium containing compounds were observed. Isotopic labelling with deuterium permitted deconvolution of ion peaks of identical mass and composition, but arising from different fragmentation pathways.
Bromothiophene reactions. I. Friedel‐crafts acylation
Authors: Agua M. J. Del , Alvarez‐Insúa A. S. , Conde S. 
Published: March 2009

AbstractFriedel‐Crafts acylation of 2,5‐dibromo‐ and 2,3,5‐tribromothiophenes with different acyl chlorides and anhydrous aluminium trichloride has been studied. The reaction afforded a mixture of acyl derivatives and tetrabromothiophene. The results obtained suggest a mechanism which involves the formation of bromine cations in the reaction medium. Several products obtained in this reaction are described.
Herstellung kondensierter 2‐alkylthio‐4‐hydroxypyrimidine
Authors: Haede Werner 
Published: March 2009

AbstractAromatische Amine werden mit Alkoxycarbonyl‐senföl in Thioharnstoffe 7 überführt. Diese werden zu S‐Alkylisothioharnstoffen 8 alkyliert, die beim Erwärmen unter Alkoholabspaltung kondensierte 2‐Alkylthio‐4‐hydroxypyrimidine 9 bilden.
Syntheses and spectral properties of 2‐Thiobiotin and biotin derivatives
Authors: Flaster Harry , Kohn Harold 
Published: March 2009

AbstractA series of methylated derivatives of 2‐thiobiotin (2‐4) have been prepared as potential aids in elucidation of the mechanism of biotin catalysis. The syntheses and mass, infrared, 1H nmr, and 13C nmr spectral properties for these substrates, their 2‐thiobiotin precursors (6, 10‐14) and the corresponding biotin analogs (1, 15, 31‐34) are described. A series of selective proton‐proton and proton‐carbon decoupling experiments were employed to secure a number of the 1H and 13C nmr assignments. Consistent patterns noted throughout the data set proved helpful in structure determination.
Ein neuer zugang zu indeno[1,2‐b]pyridinen
Authors: Kunstmann Rudolf , Lerch Ulrich , Wagner Konrad 
Published: March 2009

AbstractEs wird über eine neue Synthese von 5H‐Indeno[1,2‐b]pyridinen aus 5‐Oxo‐5‐phenylvaleronitrilen I bzw. Deren Cyclisierungsprodukten, den 6‐Phenyl‐3,4‐dihydropyridin‐2‐onen II, berichtet. Die in Polyphosphorsäure durchgeführte Kondensation von I bzw. II mit aromatischen oder heteroaromatischen Aldehyden III liefert in 5‐Stellung substituierte 1,2,3,4‐Tetrahydro‐5H‐indeno[1,2‐b]pyridin‐2‐one IV. Aus diesen kb̈nnen u.a. die bisher nur schwer zugänglichen 2,3,4,4a,5,9b‐Hexahydro‐1H‐indeno[1,2‐b]pyridine X, XI leicht hergestellt werden.
Synthèse de l'amino‐4 formyl‐3 méthyl‐6 pyridazine
Authors: Turck Alain , Brument Jean‐François , Quéguiner Guy 
Published: March 2009

AbstractNous avons préparé par deux méthodes différentes un nouveau réactif de synthèse dans la série de la pyridazine: l'amino‐4 formyl‐3 méthyl‐6 pyridazine. Ceci nous a conduit à synthétiser plusieurs composes orthodifonctionnels nouveaux de la pyridazine.
Synthesis of macrocyclic‐acyclic polyether‐ester compounds with isoxazole units
Authors: Auricchio S. , Ricca A. , De Pava O. Vajna 
Published: March 2009

AbstractA series of macrocyclic‐acyclic ether‐ester compounds containing the isoxazole ring has been prepared by treating various dihydroxy compounds with 3,5‐isoxazoledicarbonyl chloride.
Polynitroalkyltetrazoles
Authors: Grakauskas Vytautas , Albert Anthony H. 
Published: March 2009

Abstract5‐(Fluorodinitromethyl)‐and 5‐(trinitromethyl)tetrazoles were synthesized in the reactions of fluorodinitroacetonitrile with sodium azide, and trinitroacetonitrile with trimethylsilyl azide, respectively, and characterized as their ammonium salts.
Photochemistry of 4‐Pyrones in water. Formation of dihydroxycyclopentenones and furan derivatives
Authors: Pavllk James W. , Snead Thomas E. , Tata James R. 
Published: March 2009

AbstractIrradiation of aqueous solutions of aikyl substituted 4‐pyrones leads to the formation of dihydroxycyclopentenones. These primary products are also photolabile and in certain cases are photochemically converted to furan derivatives.
Steroidal thiazoles, isothiazoles, thiazolines and thiazolidines
Authors: Catsoulacos Panayotis , Camoutsis C. H. 
Published: March 2009

AbstractIn order to discover new useful steroids in which the cyclopentanoperhydrophenanthrene system is condensed with various heterocyclic rings, many new compounds are continually being synthesized and tested for physiological action. The thiazole, isothiazole, thiazoline and thiazolidine ring condensed on several positions of the steroidal skeleton, has shown great interest due to the physiological properties. Literature coverage for this review includes publications which appear from 1946 to the 1980′s.
The synthesis of substituted pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazines
Authors: Thompson Robert Douglas , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of 1,2,4‐triazolo[4,3‐b]pyridazines and the unknown ring system, pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazine, has been achieved. The preparation of the new tricyclic 1,2,4‐triazole was accomplished first by ring closure of the triazole ring followed by formation of the pyrazine ring. Substitution of the pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazine ring system was carried out in order to provide information of its reactivity and to provide a variety of interesting compounds for biological testing.
Synthesis of some new derivatives of 4‐hydrazino‐5H‐pyridazino[4,5‐b]indole
Authors: Monge‐Vega A. , Aldana I. , Ferández‐Alvarez E. 
Published: March 2009

AbstractThis paper describes the synthesis of 1‐chloro‐4‐hydrazino‐5H‐pyridazino[4,5‐b]indole (4) and some of the triazoles (6–8), tetrazoles (10–11), triazolotetrazoles (9) and bis‐tetrazoles (12) derived from it. All of these were previously unknown compounds.Treating 1,4‐dioxo‐1,2,3,4‐tetrahydro‐5H‐pyridazino[4,5‐b]indole (1) with phosphorus oxychloride gave 1,4‐dichloro‐5H‐pyridazino[4,5‐b]indole (2), which reacts regioselectively with hydrazine to give compound 4. The reactions of 4 with formic and acetic acids gave 6‐chloro‐11 H‐1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]indoles (6a‐6b), respectively. Reaction of compound 6a with hydrazine gave 6‐hydrazino‐11H‐1,2,4‐triazolo[4,3–6]‐pyridazino[4,5,‐b]indole (8). This with nitrous acid gave 6‐azido‐11H‐1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]‐indole (9). Compound 4 reacted with nitrous acid to give 6‐chloro‐11H‐tetrazolo[4,5‐b]pyridazino[4,5‐b]‐indole (10), which gave 1,4‐diazydo‐5H‐pyridazino[4,5‐b]indole (12), through successive reactions with hydrazine and nitrous acid. All compounds were characterized by elemental analysis, ir and 1H‐nmr spectra.
The reaction of 1‐hydrazinophthalazine with phthalaldehydic acid. Occurrence of ring‐chain tautomers
Authors: Amer Adel , Zimmer Hans 
Published: March 2009

AbstractA reaction involving 1‐hydrazinophthalazine (hydralazine, 1)designed to give a condensed heterocyclic system in which an eight membered ring is fused to phthalazine was investigated. With phthalaldehydic acid (2) the expected system was obtained. However, it occurs as an easily convertible mixture of ring‐chain tautomers. It was found that the course of the reaction depends on the solvent. Thus, 6,7‐dihydro‐7‐hydroxy‐12H‐phthalazino[2,1‐b][2,4]benzodiazocin‐12‐one (5) and 2‐(2‐formylbenzoyl)‐1‐hydrazono‐1,2‐dihydrophthalazine (6) were the products of the reaction of 1 with 2 in aqueous medium. Upon prolonged standing this mixture converts into 3‐(2‐carboxyphenyl)‐s‐triazolo[3,4‐a]phthalazine (8). In contrast, the isomeric ring‐chain tautomers 2‐(1‐aminophthalazino)‐3‐hydroxy‐1‐oxoisoindole (12) and 1‐[2‐(2‐formylbenzoyl)hydrazino]phthalazine (13) were formed when the reaction was run in ethanol as solvent.
Hydantoin formation from alaninamide derivatives. Reactions with 5‐amino‐5‐methylhydantoin
Authors: Zanotti Giancarlo , Pinnen Francesco 
Published: March 2009

AbstractThe influence of the α‐substitution on hydantoin formation from urethan protected alaninamide derivatives is investigated. Several 5‐methyl‐5‐substituted hydantoins, obtained from 5‐amino‐5‐methylhydantoin, are described.
Acyclic analogues of purine and imidazole nucleosides
Authors: Parkin Ann , Harnden Michael R. 
Published: March 2009

AbstractHydroxyl‐protected derivatives of 1‐ and 3‐(2‐hydroxyethoxymethyl)imidazoles (4,5,7‐10) have been prepared from 5‐amino‐4‐carbamoylimidazoles (2). The protected derivatives were converted to acyclic analogues of imidazole nucleosides (6) or subjected to various cyclisation reactions leading to 9‐(2‐hydroxy‐ethoxymethyl)‐substituted 2‐methyl‐, 2‐phenyl‐ and 2‐azahypoxanthines (18,13and20, respectively) and 1‐methylguanine (28). For assignment of structures to isomeric imidazole and purine derivatives,13C chemical shifts have been used.
Stereospecific synthesis of N‐(1‐phenylethyl)‐2,4,5‐triphenyloxazolidines
Authors: Alcaide Benito , Lopez‐Mardomingo Carmen , Perez‐Ossorio Rafael , Plumet Joaquin 
Published: March 2009

AbstractTreatment of the diastereoisomeric N‐(1‐phenylethyl)‐1,2‐diphenyl‐2‐aminoethanols with benzaldehyde yields stereospecifically N‐(1‐phenylethyl)‐2,4,5‐triphenyloxazolidines with four chiral centers. The configurations of these oxazolidines are established through their ring‐opening reactions with methylmagnesium iodide and subsequent oxidation with lead tetracetate.
Diazo‐, azo‐, and azidoazoles. VII. Imidazo[1,2‐b]‐ versus imidazo[2,1‐c]benzo‐as‐triazines
Authors: Castillón Sergio , Meléndez Enrique , Vilarrasa Jaume 
Published: March 2009

AbstractTreatment of 3‐aminobenzo‐as‐triazines with bromoacetaldehyde ethylene acetal give linear tricyclic imidazobenzo‐as‐triazines, where 3‐amino‐7‐methylbenzo‐as‐triazine 1‐oxide yields the angular isomer. The structures of these compounds have been established by comparing their nmr spectra to those of pyrazolo [5,1‐c]‐ and s‐triazolo[5,1‐c]benzo‐as‐triazines obtained form the appropriate azo derivatives by intramolecular cyclization.
Configuration and conformation of substituted azetidines
Authors: Kingsbury C. A. , Soriano D. S. , Podraza K. F. , Cromwell N. H. 
Published: March 2009

AbstractStudies of compounds such as 1‐cyclohexyl‐2‐carbomethoxy‐4‐methylazetidine by H‐1 nmr coupling constants, nuclear Overhauser effects, C‐13 steric shifts, and N‐15 nmr support the revised assignment of configuration for cis/trans isomers in a series of N‐alkyl substituted azetidines. The trans isomer displayed spectral characteristics consistent with a planar or nearly planar ring. The cis isomer favors a puckered ring, with major substituents at C‐2 and C‐4 equatorial. Compounds lacking the C‐4 methyl are also puckered. Puckering angles are estimated. In contrast, trans‐1‐cyclohexyl‐2‐carboxy‐4‐methylazetidine (a zwitterion) prefers a puckered ring, possibly implicating the time averaged effect of nitrogen inversion on ring shape. The N‐15 spectra show a large difference in chemical shift between cis and trans isomers of the azetidines, although analogous aziridines show an even larger difference.
Tetracyclic phenothiazines. VI. Attempted pummerer cyclization of 10‐(2‐Keto‐3‐methylsulfinylpropyl)phenothiazine
Authors: Vishwakarma L. C. , Martin A. R. 
Published: March 2009

AbstractThe title compound (3), a β‐ketosulfoxide prepared by a Claisen‐type condensation of ethyl 2‐(10‐phenothiazino)acetate (4) with dimsyl carbanion, was subjected to a variety of catalysts in attempts to achieve a Pummerer cyclization to 1,2‐dihydro‐3‐methylthio‐2‐oxo‐3H‐pyrido[3,2,1‐kl]phenothiazine (2). Although the Pummerer rearrangement product, 10‐(2‐oxo‐3‐hydroxy‐3‐methylthiopropyl)phenothiazine (5), could be obtained in excellent yield under mild conditions, neither it nor the β‐ketosulfoxide could be successfully cyclized under any of the conditions attempted. Instead, phenothiazine, 2‐hyroxy‐3‐(10‐phenothiazinyl)‐2‐propen‐1‐al (7), 3‐(10‐phenothiazinyl)‐1,1‐di(methylthio)propan‐2‐one (8), 3‐(10‐phenothiazinyl)‐1‐methylthiopropan‐2‐one (9) and 10‐phenothiazinylformamide (10) were variously obtained.
Effect of p‐substitution on the spectroscopic properties of 1,2‐dihydro‐4H‐2‐phenyl‐3,1‐benzoxazines
Authors: Saeed Ali A. H. 
Published: March 2009

AbstractA series of 1,2‐dihydro‐4H‐2‐phenyl‐3,1‐benzoxazines (I) were obtained by condensation of o‐aminobenzyl alcohol and substituted benzaldehyde. The effect of p‐substitution on their spectroscopic properties was investigated by uv and mass spectroscopy.
Synthesis of 3‐(1‐hydroxyalkyl)‐4,5,6,7‐tetrahydroindazole derivatives. Structure determination of N‐alkyl isomers
Authors: Dolmazon René , Gelin Suzanne 
Published: March 2009

AbstractA novel series of 3‐(1‐hydroxyalkyl)‐4,5,6,7‐tetrahydroindazoles and their 1 and 2‐alkyl‐3‐(1‐hydroxyalkyl)‐or‐3‐(1‐acetoxyalkyl) derivatives were synthesized via condensation between 3‐oxo‐2,3,4,5,6,7‐hexahydrobenzo[b]furans or 2‐(2‐acetoxyacyl)cyclohexanones and hydrazines. Structure assignment are based on 1H and 13C nmr spectra.