bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear hydroxylated metabolite of fluradoline (2‐fluoro‐11‐[(β‐methylamino)ethylthio]dibenz[b,f]oxepin hydrochloride). Identification and synthesis
Authors: Agnew Marc N. , Rizwaniuk Anastasia , Ong Helen H. , Wichmann J. K. 
Published: March 2009

AbstractFluradoline (2‐fluoro‐11‐[β‐(methylamino)ethylthio]dibenz[b,f]oxepin), a novel analgesic with an unique profile, was found to be extensively metabolized in man as well as in other species. One of the major metabolites of this drug appeared to be a nuclear hydroxylated derivative of the parent compound, and the site of enzymatic hydroxylation was established to be C(7) by using high‐field proton nuclear magnetic spectroscopy. This structural assignment was subsequently confirmed by the synthesis of an authentic sample of 2‐fluoro‐7‐hydroxy‐11‐[β‐(methylamino)ethylthio]dibenz[b,f]oxepin (2a).
Heterocyclen aus α‐nitroolefinen. XI . 1,2‐oxazine aus α‐nitroolefinen und β‐dicarbonylverbindungen
Authors: Boberg Friedrich , Ruhr Maria , Garburg Karl‐Heinz , Garming Alfons 
Published: March 2009

AbstractDihydro‐1,2‐oxazine 8 und 1,2‐Oxazine 12 werden aus Nitronsäuren der Addukte aus α‐Nitroolefinen und β‐Dicarbonylverbindungen (6) auf zwei Wegen hergestellt: A) Die Nitronsäuren 6 werden in einer siedenden Lösung von Harnstoff in Ethanol oder Methanol erhitzt. B) Die Nitronsäuren 6 werden mit einer wäßrigen Ammoniumchlorid/Natriumsulfid‐Lösung reduziert. 1H‐NMR‐ und 13C‐NMR‐Untersuchungen beweisen die Konstitutionen. Der Mechanismus wird diskutiert.
Determination of structure and 13C chemical shift assignments of the nitration products of 2‐chloro‐10‐methylphenothiazine. X‐Ray molecular structure of 2‐chloro‐7‐nitro‐10‐methylphenothiazine 5‐oxide
Authors: Jovanovic Misa V. , Biehl Edward R. , De Meester Patrice , Chu Shirley S. C. 
Published: March 2009

AbstractNitration of 2‐chloro‐10‐methylphenothiazine, 1, yields two mono‐nitro compounds identified as sulfoxide 2 and sulfone 3. The nmr analyses of the 13C spectra of 2 and 3 establish unequivocally that in both compounds substitution has occurred at the seven position. This is supported by the X‐ray crystal structure of one of the compounds 2‐chloro‐7‐nitro‐10‐methylphenothiazine 5‐oxide, 2, which also shows that the sulfoxide group is in the “pseudo‐axial” configuration. Crystals of 2 are monoclinic, space group P21/n, a = 11.606(4), b = 13.970(4)Å, c = 9.837(2), β = 127.49(2)° and Z = 4. The structure has been refined by full‐matrix least‐squares to R = 0.033 and Rw = 0.035, using 1704 observed reflections.
Synthesis and fluorescence of N‐substituted‐1,8‐naphthalimides
Authors: Middleton Richard W. , Parrick John , Clarke Eric D. , Wardman Peter 
Published: March 2009

AbstractA number of novel N‐substituted‐1,8‐naphthalimides have been prepared and their fluorescence yields measured in water at pH 7.4. The type of substitutent and the substitution pattern on the naphthalimide nucleus produce markedly different fluorescence yields, (quantum efficiencies, ø varying from ø = 0‐0037 for N‐(3‐N'‐morpholino‐1‐propyl)‐4‐amino‐3‐methoxy‐1,8‐naphthalirnide (7) to ø = 0–77 for N‐(3‐bromopropyl)‐4‐acetamido‐1,8‐naphthalimide (31).
Studies on pyrazines. 14 The syntheses of 2,5‐dihydroxypyrazines and their derivatives
Authors: Adachi Jiro , Sato Nobuhiro 
Published: March 2009

AbstractReaction of phenylglycinamide (1c) with ethyl benzoylformate (2c) in the presence of refluxing ethanolic sodium ethoxide gave 2,5‐dihydroxy‐3,6‐diphenylpyrazine (3i) in 19% yield. This synthetic method, however, was limited to the preparation of 3i. On the other hand, α‐aminoamides 1 condensed with α‐ketoesters 2 to give the intermediates 5, which were also prepared by condensation of 1 with α‐ketalesters 6, followed by hydrolysis of the ketal moeity. Cyclization of 5 with refluxing methanolic sodium methoxide gave only disubstituted 2,5‐dihydroxypyrazines 3. Acetylation of 5 with refluxing acetic anhydride/acetic acid led to direct formation of 2,5‐diacetoxypyrazines 9. Similarly, compounds 5 could be converted into 2,5‐dichloropyrazines 4.
Bridged isocytosine‐adenosine compounds: Synthesis and antibacterial evaluation
Authors: Lever O. William , Vestal B. Randall 
Published: March 2009

AbstractIn an approach to novel antibacterial agents, we synthesized a series of 5‐nitrosoisocytosines in which a 6‐alkylamino substituent is bridged, through an amide linkage at the terminus of the alkyl chain, to the 5′‐position of a 5′‐deoxyadenosine moiety. A corresponding series of 5‐nitro analogues were also prepared. None of the bridged compounds showed significant antibacterial activity.
Determination of the preferred tautomeric form of 4‐nitrohistidine
Authors: Pedroso Enrique , Grandas Anna , Ludevid Ma. Dolors , Giralt Ernest 
Published: March 2009

AbstractSpectrophotometric pKa determinations of methyl derivatives of Nα‐acetyl‐4‐nitrohistidine methyl ester 1 have been used to determine the position of the tautomeric equilibrium of 1. The N1‐H tautomer is the predominant form with an equilibrium constant KT of 48.The conclusion is supported qualitatively by the study of 1H‐nmr and 13C‐nmr chemical shifts of the imidazole ring atoms and their changes from neutral to acidic media.
Syntheses of substituted pyrazolo[3,4‐b]quinolines, 3,4‐dihydro‐4‐oxopyrimido[4′,5′:4,5]theino[2,3‐b]quinoline and pyrido[1′,2′:1,2]pyrimido[4,5‐b]quinoline
Authors: Neelima  , Bhat Balkrishen , Bhaduri Amiya Prasad 
Published: March 2009

AbstractSyntheses of substituted pyrazolo[3,4‐b]quinolines, 3,4‐dihydro‐4‐oxopyriraido[4′,5′:4,5]theino[2,3‐b]quinoline and 12‐phenylpyrido[1′,2′:1,2[pyrimido[4,5‐b]quinoline are described.
Synthesis of 2‐ and 3‐substituted‐1,2,3,4‐tetrahydrodibenzo[f,h]isoquinolines
Authors: Grande Mercedes T. , Trigo Gregorio G. , Söllhuber Mónica M. 
Published: March 2009

AbstractSome 2‐ and 3‐substituted‐1,2,3,4‐tetrahydrodibenzo[f,h]isoquinolines were prepared by a synthetic scheme involving a selective Borch reduction of an amide to the corresponding amine and a Friedel‐Crafts cyclization to obtain the dibenzo[f,h]isoquinoline system. The title compounds, which have a similarity to the cell growth inhibitory alkaloid cryptopleurine, failed to exhibit significant protein synthesis inhibitory activity.
Base‐Catalyzed cyclization of N‐propargylamides to oxazoles
Authors: Nilsson Björn M. , Hacksell Uli 
Published: March 2009

AbstractThe base‐catalyzed cyclization of some N‐propargylamides to oxazoles has been studied in the presence of sodium hydride and potassium carbonate. The α‐arylsubstituted propargylamides 1c‐d (Ar = p‐OMeC6H4 (1c), C6H5 (1d), and p‐O2NC6H4 (1e)) cyclized with markedly higher rates (1e > 1d > 1c) than the unsubstituted and α‐methyl substituted propargylamides 1a and 1b. A 1H nmr spectroscopic experiment demonstrated the presence of an allenic intermediate in the potassium carbonate‐catalyzed ring closure of 1e. The observed rank order of reactivities correlates well with the acidities of the respective propargylic hydrogens of the amides and with the ability of the ring closed intermediates to stabilize an oxazole anion. The results demonstrate that the base‐catalyzed formation of oxazoles from propargylamides may proceed via an allenic intermediate.
Synthesis, structural and conformational study of 4‐α‐(or β)‐p‐chlorobenzoyloxy‐1‐azaadamantane hydrochloride
Authors: Fernandez M. J. , Galvez E. , Lorente A. , Soler J. A. , Florencio F. , Sanz J. 
Published: March 2009

Abstract4‐α‐(or β)‐p‐Chlorobenzoyloxy‐1‐azaadamantane hydrochloride have been synthesized and studied by 1H and 13C nmr spectroscopy, and the crystal structure of the α‐epimer has been determined by X‐ray diffraction. Each ring of the adamantane cage system is a nearly perfect chair, the substituted cyclohexane and piperidine rings, in endo and exo position respectively, having the biggest deviation. From the 1H and 13C nmr data, several stereoelectronic effects have been deduced.
Cycloaddition reactions of cephalosporin compounds. XI. 1,3‐dipolar cycloaddition reaction of an exo‐2‐methylenecephem with diphenyldiazomethane
Authors: Pitlik János , Jászberényi J. Csaba 
Published: March 2009

AbstractIn the 1,3‐dipolar cycloaddition reaction of the exo‐2‐methylenecephem 6 with diphenyldiazomethane the initially formed pyrazolines decompose and spirocyclopropylcephalosporin formation takes place. The structure elucidation with 1H, 13C, ASIS and NOE nmr methods is also described.
Electron impact mass spectrometry of 2‐(methoxycarbonylmethyl)‐2‐phenyl‐1,3‐benzoxathiole and 2‐acetonyl‐2‐phenyl‐1,3‐benzoxathiole
Authors: Prison Giampietro , Traldi Pietro , Cocco Maria Teresa , Podda Gianni 
Published: March 2009

AbstractThe electron impact mass spectrometric behaviour of 2‐(methoxycarbonylmethyl)‐2‐phenyl‐1,3‐benzoxa‐thiole 3a and 2‐acetonyl‐2‐phenyl‐1,3‐benzoxathiole 3b has been studied in detail. The structures of the more interesting fragment ions have been confirmed with the aid of accurate mass measurements, linked scans and collisional activation experiments. In addition to the ionic species already described in the general fragmentation pattern of 1,3‐benzoxathiole derivatives, other fragments arising from the interaction of the carboxy‐containing chain with the sulfur atom of these compounds have been observed and evidence presented.
Synthesis of new gramine‐type analogs of CC‐1065
Authors: Rajeswari Sundaramoorthi , Adesomoju Akinbo A. , Cava Michael P. 
Published: March 2009

AbstractPreparation of two new analogs 5 and 6 of the antitumor antibiotic CC‐1065 1 are described. These compounds represent structural modifications of the active analogs 3 and 2 respectively, in which the dienone A‐unit has been replaced by the tricyclic achiral gramine unit 4. Modest cytotoxicity was exhibited by compounds 5 and 6.
Synthesis of new alkyl‐ alkenyloxy‐ and hydroxy‐substituted diaza‐crown compounds
Authors: Bradshaw Jerald S. , Krakowiak Krzysztof E. , Izatt Reed M. 
Published: March 2009

AbstractNew diaza‐crown compounds with the macro ring nitrogen atoms situated in the 1, 4‐, 1, 7‐ and 1, 10‐positions have been prepared. All of the new macrocycles contain alkyl groups on the nitrogen atoms and a functional group substituent in the form of either an allyloxymethyl, allyloxy or hydroxy group on one of the macro ring carbon atoms. A 1, 4‐diaza‐crown attached to silica gel removes Hg(II) ions from an aqueous mixture of Hg(II), Cd(II) and Zn(II) ions.
Studies on heterocyclic compounds. VII. Syntheses of novel furo[2, 3‐b]chromones
Authors: Kuo Sheng‐Chu , Wu Jiin‐Sheng , Huang Li‐Jiau , Wu Chun‐Hsiung , Huang Shun‐Chueh , Chou Teh‐Chang 
Published: March 2009

AbstractFuro[2, 3‐b]chromone (1a) was conveniently prepared by the PPE‐promoted cyclization of 5‐(2′‐carboxy‐phenoxy)furan‐2‐carboxylic acid (8) which was made from methyl salicylate and ethyl 5‐nitrofuran‐2‐carboxyl‐ate. Furo[2, 3‐b]chromon‐2‐acrylic acid (13) was obtained by a similar cyclization. Direct acylation of 1a afforded 2‐acetylfuro[2, 3‐b]chromone (10). Several derivatives of furo[2, 3‐b]chromone were found to display activity in the rat passive cutaneous anaphylaxis (PGA) test for antiallergic activity.
Hydrogenation of substituted 1‐arylisoquinolin‐3(2H)‐ones to 5, 6, 7, 8‐tetrahydro‐ and 1, 4‐dihydroisoquinolin‐3(2H)‐ones
Authors: Hazai László , Deák Gyula , Tóth Gábor , Tamás József 
Published: March 2009

AbstractCatalytic hydrogenation of variously substituted 1‐arylisoquinolin‐3(2H)‐ones 1 gave, depending on the substituents, 5, 6, 7, 8‐tetrahydroisoquinolin‐3(2H)‐ones (2) and/or the corresponding 1, 4‐dihydro derivatives 3. Saturation of the compounds fused with benzene ring furnished as the main products the 9, 10‐dihydro‐ (4 and 5) and 5, 6‐dihydroisoquinolin‐3(2H)‐ones (6) in the case of benzo[f] and benzo[h] anellation, respectively, in addition to the 1, 4‐dihydro compounds detected or isolated as by‐products.
Tautomerism in barbituric and thiobarbituric acids
Authors: Millefiori Salvatore , Millefiori Arcangelo 
Published: March 2009

AbstractThe molecular geometry of barbituric and thiobarbituric acid tautomers have been fully optimized using the AMI method in order to estimate the relative energies of the tautomers. The results are in agreement with available experimental data and indicate that in the vapour the barbiturate ring is essentially planar. In both unsubstituted compounds the trioxo structure is found to be the most stable one, in agreement with experimental findings in the solid. Tautomeric equilibria are sensitive to phase change and to substitution at the C5 position. On passing from the vapour to the water the population of the most polar structure increases, although the order of stability remains unchanged and only for the Br and I derivatives it can be suggested the coexistence of two forms in solution. The substitution at C5 does not alter the order of stability except for the 5‐nitro derivatives where the dioxo form predominates, in agreement with experimental results in the solid. Electron affinities and ionization potentials of the tautomers have been evaluated and briefly discussed. It is suggested that gas‐phase uv photoelectron spectroscopy should be able in analysing the tautomeric equilibria of barbituric and thiobarbituric acids in the vapour.
Reaction of 4‐hydrazinoquinolines with β‐diketones. Synthesis and spectroscopy (1h, 13c nmr, ms) of some pyrazolylquinolines
Authors: Singh S. P. , Tarar L. S. , Vaid R. K. , Elguero J. , Martínez A. 
Published: March 2009

AbstractA series of 4‐pyrazolylquinolines have been prepared from 4‐hydrazinoquinolines and β‐dicarbonyl compounds and the previously proposed diazepine structure for the reaction products has been ruled out. A 13C nmr study established the 3‐position of the methyl group when two isomers were possible. Finally, a careful 1H nmr study of 2‐ and 4‐pyrazolylquinolines led to the conclusion that intramolecular hydrogen bonds between aromatic (or heteroaromatic) C‐H and pyridine like nitrogens is the factor that determines the conformation of these compounds.
A facile one pot synthesis of 1‐alkylbenzimidazoline‐2‐thiones
Authors: Lee Tae Ryong , Kim Kyongtae 
Published: March 2009

AbstractReactions of benziraidazoline‐2‐thione with alkyl halides in the presence of sodium naphthalenide in tetra‐hydrofuran at room temperature under a nitrogen atmosphere afforded 1‐alkyl‐2‐alkylthiobenzimidazoles in excellent yields, which underwent a bond cleavage between S and C of alkyl group to give excellent yields of 1‐alkylbenzimidazoline‐2‐thiones by the treatment with an additional amount of sodium naphthalenide.
Reaction of nitriles under acidic conditions. Part VI. Synthesis of condensed 4‐chloro‐ and 4‐aminopyrimidines from ortho‐aminonitriles
Authors: Shishoo C. J. , Devani M. B. , Bhadti V. S. , Jain K. S. , Ananthan S. 
Published: March 2009

AbstractCondensation of a nitrile with benzene, furan and thiophene ortho‐aminonitriles in the presence of dry hydrogen chloride yields condensed 4‐chloropyrimidines, condensed 4‐aminopyrimidines or a mixture of the two condensed pyrimidines in varying proportions depending upon the nature of the nitrile and the substrate, ortho‐aminonitrile.
Studies in organic mass spectrometry. VIII. The electron impact mass spectra of 2,4‐substituted‐3‐diazo‐5‐phenylpyrroles
Authors: Ceraulo L. , Agozzino P. , Ferrugia M. , Plescia S. , Sprio V. 
Published: March 2009

AbstractThe electron impact mass spectra (75 eV) of the β‐diazopyrroles always show the molecular ions and undergo as the main fragmentation process the elimination of nitrogen followed by ring opening reactions leading to benzonitrile either as neutral or charged species. The peaks at 26 amu below the molecular ions, which are a general feature of these spectra, are due to the presence of the corresponding pyrroles which are formed by reductive reactions during the vaporization process of the samples.
Synthesis of 4,4′‐divinyl‐2,2′‐bipyridine
Authors: Ciana Leopoldo Delia , Dressick Walter J. , Von Zelewsky A. 
Published: March 2009

Abstract4,4′‐Divinyl‐2,2′‐bipyridine (2) was prepared in 12% overall yield from 4,4′‐dimethyl‐2,2′‐bipyridine (3) via a 5 step reaction sequence involving the intermediate 4,4′‐R2‐2,2′‐bipyridines: R = COOH, 4; CO2CH3, 5; CH2OH, 6; CHO, 7. The newly synthesized compounds 2, 6 and 7 were characterized by melting point, infrared, 1H nmr, mass spectrometry and elemental analysis.
9‐Deazapurine nucleosides. The synthesis of certain N‐5‐β‐d‐ribofuranosylpyrrolo[3,2‐d]pyrimidines
Authors: Girgis Nabih S. , Robins Roland K. , Cottam Howard B. 
Published: March 2009

AbstractSeveral N‐5 ribofuranosyl‐2,4‐disubstituted pyrrolo[3,2‐d]pyrimidine (9‐deazapurine) nucleosides were prepared by the single phase sodium salt glycosylation of 2,4‐dichloro‐5H‐pyrrolo[3,2‐d]pyrimidine (3) using 1‐chloro‐2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dirnethylsilyl‐α‐D‐ribofuranose (2). Use of 2 for the glycosylation avoided the formation of “orthoamide” products 1 and provided an excellent yield of the β nucleoside, 2,4‐dichloro‐5‐[2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dimethylsilyl‐β‐D‐ribofuranosyl]‐5H‐pyrrolo[3,2‐d]pyrimidine (4), along with a small amount of the corresponding α anomer, 5. Compound 4 served as the versatile intermediate from which the N‐7 ribofuranosyl analogs of the naturally‐occurring purine nucleosides adenosine, inosine and guanosine were synthesized. Thus, controlled amination of 4 followed by sugar deprotection and dehalogenation yielded the adenosine analog, 4‐amino‐5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]pyrimidine (8) as the hydrochloride salt. Base hydrolysis of 4 followed by deprotection gave the 2‐chloroinosine analog, 10, and subsequent dehalogenation provided the inosine analog, 5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]‐pyrimidin‐4(3H)‐one (11). Amination of 10 furnished the guanosine analog, 2‐amino‐5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]pyrimidin‐4(3H)‐one (12). Finally, the α anomer in the guanosine series, 16, was prepared from 5 by the same procedure as that used to prepare 12. The structural assignments were made on the basis of ultraviolet and proton nmr spectroscopy. In particular, the isopropylidene intermediates 9 and 14 were used to assign the proper configuration as β and α, respectively, according to Imbach's rule.
Synthesis of acenaphtho[1,2‐x]heterocycles and spiro[acenaphthylene 1‐isoxazoles]
Authors: Lefkaditis D. A. , Nicolaides D. N. , Papageorgiou G. K. , Stephanidou‐Stephanatou J. 
Published: March 2009

AbstractMethyl (Z)‐(1,2‐dihydro‐2‐oxo‐1‐acenaphthylenylidene)acetate 1 gives with hydroxylamine the oximes 2 and the pyrrole derivative 4, whereas with hydrazines affords the pyridazinones 5 and 6. A pyridazine derivative 8 is also isolated from the reaction of (1,2‐dihydro‐2‐oxo‐1‐acenaphthylenylidene)acetone 7 with hydrazine hydrate. Reaction between the spiro‐derivative 9 and hydroxylamine hydrochloride gives oxime 10, whereas Wittig olefination of 9 with ylide 11 yields compound 12 which by reaction with 2,4,6‐trimethylbenzonitrile oxide (13) affords the dispiro‐derivatives 14. Finally from the reaction of acenaphthylene‐1,2‐quinone (17) with the bisylide 16 the acenaphtho[1,2‐c]thiophene (18) is formed.
Structure and spectroscopic characterization of 1‐ and 2‐hydrazonoyl‐1,2,3‐triazoles
Authors: Bojilova Anka , Rodios Nestor A. , Alexandrou Nicholas E. , Terzis A. , Mentzafos D. 
Published: March 2009

AbstractThe synthesis of some 1‐ and 2‐hydroazonoyl‐1,2,3‐triazoles by reaction of the corresponding 1,2,3‐triazoles and nitrilimines is described and their characterization by 13C nmr and mass spectroscopy is provided. The structure of a 2‐hydrazonoyl derivative 6b was determined by X‐ray analysis.
Polarized ethylene. V. Synthesis of 1‐substituted indolizine, pyrazolo[1,5‐a]pyridine, and their related compounds using methoxyethylene derivatives
Authors: Tominaga Yoshinori , Ichihara Yuichi , Mori Tomoko , Kamio Chizuko , Hosomi Akira 
Published: March 2009

AbstractThe reaction of pyridinium or isoquinolinium N‐ylides with methoxy‐substituted ethylenes gave the corresponding indolizine and pyrrolo[2,1‐a]isoquinoline derivatives bearing acetyl, aroyl, cyano, ester group at the 1‐position in one step. Pyrazolo[1,5‐a]pyridine, pyrazolo[1,5‐a]quinoline, and pyrazolo[5,1‐a]isoquinolines were also synthesized in good yields from the corresponding aromatic N‐imines and methoxyethylene derivatives.
Diheterocyclic compounds from dithiocarbamates and derivatives thereof. II. 2,2′‐Diamino‐6,6′‐bibenzoazoles
Authors: Garín Javier , Meléndez Enrique , Merchán Francisco L. , Merino Pedro , Orduna Jesús , Tejero Tomás 
Published: March 2009

AbstractThe readily available dithiocarbamates and dithiocarbonimidates 4, 8, 14 and 15 afford in one step the title compounds in medium to very good yields. In each case, the choice of reagent depends on the nature of the group to be introduced. Their usefulness as synthetic equivalents of weakly reactive or unavailable isothiocyanates is also discussed.
Condensed 1,3‐benzothiazinones 3. Synthesis of 3‐substituted 1,2,4‐triazolo[3,4‐b][1,3]benzothiazin‐5‐ones
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Chern Ji‐Wang 
Published: March 2009

AbstractRefluxing 2‐hydrazono‐3,4‐dihydro‐2H‐1,3‐benzothiazin‐4‐one 3 with triethyl orthoformate neat or with trimethyl orthoformate 4a, triethyl orthoacetate, orthopropionate, orthobenzoate 4b‐d in xylene gave 1,2,4‐triazolo[3,4‐b][1,3]benzothiazin‐5‐one 2a and its 3‐substituted derivatives 2b‐d in 56–95% yields. On the other hand, when 3 was treated with trifluoro‐, trichloroacetic anhydride 4e,f, dichloro‐, chloroacetyl chloride 4g,h, 2‐chloropropionyl and ethoxyoxalyl chloride 4i,j, the corresponding open‐chain condensates were produced, together with the title compounds 2g‐i, or the Dimroth rearrangement isomers 1e,g,i,j each depending on the reaction conditions. Nevertheless efficient preparation of 2h and 3‐hydroxy‐derivative 2k to get rid of such rearrangement was developed.
Heterocyclic compounds with a bridgehead nitrogen atom. Synthesis in the imidazo[1,2‐c]quinazoline series
Authors: Gueiffier A. , Viols H. , Chapat J. P. , Chavignon O. , Teulade J. C. , Dauphin G. 
Published: March 2009

AbstractThe structures of imidazo[1,2‐c]quinazolines were reexaminated and established by spectroscopic studies with the aid of high‐field 1H and 13C nmr and mass spectra. In acidic media, 3 reacts to give the products of electrophilic substitution reaction and ring opening compound 5, leading to the imidazo[1,2‐c]benzo[e]‐[1,2,3]triazine ring.
Reactivity of 2‐methyl‐4‐(1‐pyrrolidinyl)‐2H‐1,2‐benzothiazine 1,1‐dioxide towards p‐toluenesulphonyl azide
Authors: Consonni Roberto , Croce Piero Dalla , Ferraccioli Raffaella 
Published: March 2009

AbstractThe 2‐methyl‐2H‐1,2‐benzothiazin‐4‐(3H)‐one 1,1 dioxide (2), obtained according to a new, one‐pot method, is transformed into the pyrrolidino enamine 3. Reaction of p‐toluenesulphonyl azide with 3 gives, via an unstable triazoline adduct which loses nitrogen, the two isomeric tosylamino derivatives 4 and 5. The structures have been assigned by exhaustive nmr analysis and some aspects on their formation and chemical behaviour are discussed.