bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemistry of thienopyridines. XXXV. Synthesis, tautomerism, and reactions of quinoline and thienopyridine systems which bear a 1‐carboethoxy‐1‐cyanomethyl substituent in the pyridine ring, part 2
Authors: Klemm L. H. , Lu Jennifer J. , Greene Diana S. , Boisvert William 
Published: April 2009

AbstractA comparison is made amongst the isosteric Systems quinoline, thieno[2,3,‐b]pyridine, and thieno[3,2‐b]‐pyridine which bear the 1‐carboethoxy‐1‐cyanomethyl substituent (R) alpha or gamma to the heterocyclic nitrogen atom. Treatment of thieno[3,2‐b]pyridine 4‐oxide with ethyl cyanoacetate and acetic anhydride at room temperature (Hamana reaction) gives the alpha R‐derivative 6 (27%), formulated as an intramolecular H‐bonded structure. Neither 6 nor its quinoline alpha analog reacts with refluxing acetic anhydride, while the quinoline gamma isomer 8, existing as NH and CH tautomers, yields an N‐acetyl derivative 10 (70%) under similar conditions. For each of 6 and 8 one can isolate two crystalline forms which differ considerably in color. Compound 10 and its gamma analog in the thieno[2,3‐6]pyridine series (previously obtained directly from a Hamana reaction) serve as acetylating agents for aniline, 1‐aminobutane, morpholine, and cholesterol. Correlations and contrasts in the three Systems are presented.
Regiospecific hydrogenation of quinolines and indoles in the heterocyclic ring
Authors: Shaw J. E. , Stapp P. R. 
Published: April 2009

AbstractQuinolines, indoles, acridine, and carbazole were hydrogenated using a large variety of heterogeneous catalysts in hydrocarbon solvents in an effort to achieve selective hydrogenation of the heterocyclic ring. When quinolines were hydrogenated using supported platinum, palladium, rhodium, ruthenium, or nickel metal catalysts in the presence of hydrogen sulfide, carbon disulfide, or carbon monoxide, there was exclusive hydrogenation of the heterocyclic ring to give only 1,2,3,4‐tetrahydroquinolines. Use of iridium, rhenium, molybdenum(VI) oxide, tungsten(VI) oxide, chromium(III) oxide, iron(III) oxide, cobalt(II) oxide‐molybdenum(VI) oxide, or copper chromite catalysts also caused exclusive hydrogenation of the heterocyclic ring even without addition of sulfur Compounds or carbon monoxide. Hydrogenation of indoles using platinum, rhenium, or, in some cases, nickel catalysts (with or without sulfur Compounds) occurred exclusively in the heterocyclic ring to give indolines, but conversions were affected by indole‐indoline equilibria.
Unexpected course of the reaction of aromatic aldehydes on lithiated N,N‐dimethyl o‐(3‐quinolyl)carbamate
Authors: Robin Y. , Godard A. , Queguiner G. 
Published: April 2009

AbstractThe reaction of aromatic aldehydes with N,N‐dimethyl O‐(3‐lithioquinolyl)carbamate produces 4‐(dimethyl‐aminomethyl)3‐hydroxyquinolines via a new rearrangement.
Reaction of N,N‐dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) with 1,3‐dimethyl‐4‐aminouracils. A new “one pot” synthesis of 3‐aryl‐(and 3‐alkyl)‐4,6‐dimethyl‐5,7‐dioxo‐1,2,3‐triazolo[4,5‐d]pyrimidines (8‐azatheophyllines) via a diazo group transfer process
Authors: Kokel Bruno , Boussouira Nadia 
Published: April 2009

AbstractN,N‐Dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) (1) reacts by diazo group transfer with 1,3‐dimethyl‐4‐aryl‐(and alkyl)aminouracils 4 to give, under mild “one pot” reaction conditions, a very good yield of 3‐aryl‐(and 3‐alkyl)‐4,6‐dimethyl‐5,7‐dioxo‐1,2,3‐triazolo[4,5‐d]pyrimidines (8‐azatheophyllines) 8. That reaction proceeds, very likely, through formation of non‐isolated 4‐imino‐5‐diazouracils 6.
Silica gel assisted reductive cyclization of 2‐nitro‐β‐piperidinostyrenes, derived from 2‐nitrotoluenes, to indoles
Authors: Kawase Masami , Sinhababu Achintya K. , Borchardt Ronald T. 
Published: April 2009

AbstractAn efficient modification of the Leimgruber‐Batcho method of indole synthesis has been devised that facilitates the synthesis of a variety of 2,3‐unsubstituted indoles containing halogen, methoxy and benzyloxy groups, from 2‐nitrotoluenes, in high yields. The modified method involves the condensation of 2‐nitrotoluenes with tripiperidinomethane followed by the reductive cyclization of the intermediate 2‐nitro‐β‐piperidinostyrenes with iron and acetic acid in refluxing toluene in the presence of silica gel (column chromatography grade, 60–200 mesh).
On triazoles. X. The reaction of 5‐amino‐1,2,4‐triazoles with tetrahydrothiophene β‐keto esters
Authors: Esses‐Reiter Klára , Reiter József 
Published: April 2009

AbstractThree novel ring systems, namely the thieno[3,4‐d]‐1,2,4‐triazolo[1,5‐a]pyrimidine, the thieno[3,4‐e]‐1,2,4‐triazolo[1,5‐a]pyrimidine and the thieno[3,2‐d]‐1,2,4‐triazolo[1,5‐a]pyrimidine were synthesised. The structure of compounds obtained was proved with the help of their uv and cmr spectra using model compounds prepared for this purpose.
The synthesis of [1]benzothieno[2,3‐c]quinolines, [1]benzothieno[2,3‐c][1,2,4]triazolo[4,3‐a]quinoline, and [1]benzothieno[2,3‐c]tetrazolo[1,5‐a]quinoline
Authors: McKenney J. Dew , Castle Raymond N. 
Published: April 2009

AbstractPhotocyclization of 3‐chloro‐N‐phenylbenzo[b]thiophene‐2‐carboxamide 10 afforded [1]benzothieno[2,3‐c]‐quinolin‐6(5H)‐one 11 which was chlorinated to 6‐chloro[1]benzothieno[2,3‐c]quinoline 12 followed by dechlorination to give [1]benzothieno[2,3‐c]quinoline 5. A series of 6‐substituted alkoxy and thioalkoxy[1]benzothieno[2,3‐c]quinoline derivatives were prepared along with the N‐methyl quaternary salt 13 of 5. 6‐Chloro[1]‐benzothieno[2,3‐c]quinoline 12 was converted into 6‐hydrazino[1]benzothieno[2,3‐c]quinoline 23 which upon treatment with formic acid yielded [1]benzothieno[2,3‐c][1,2,4]triazolo[4,3‐a]quinoline 6. Treatment of 23 with nitrous acid resulted in [1]benzothieno[2,3‐c]tetrazolo[1,5‐a]quinoline 7. Compounds 6 and 7 are novel heterocyclic ring systems.
Short syntheses of 1,2,3,5‐tetrahydro‐5‐oxopyrrolo‐[1,2‐a]quinoline‐4‐carboxylic acid and 1,2,3,4‐tetrahydro‐6H‐6‐oxopyrido[1,2‐a]quinoline‐5‐carboxylic acid derivatives
Authors: Chu Daniel T. W. , Claiborne Akiyo K. 
Published: April 2009

AbstractShort and efficient syntheses of 7‐fluoro‐8‐(4‐methylpiperazin‐1‐yl)‐1,2,3,5‐tetrahydro‐5‐oxopyrrolo[1,2‐a]‐quinoline‐4‐carboxylic acid and 8‐fluoro‐9‐(4‐methylpiperazin‐1‐yl)‐1,2,3,4‐tetrahydro‐6H‐6‐oxopyrido[1,2‐a]‐quinoline‐5‐carboxylic acid are described. Both basic heterocycles were synthesized in two steps by the condensation of a benzoylacetate with an imino ether followed by an intramolecular nucleophilic displacement cyclization reaction.
Synthesis of novel 1,2,3,4‐tetrahydrobenzo[c]‐1,5‐naphthyridines from pyrrolo[1,2‐b]isoquinolines
Authors: Martin Lawrence L. , Scott Susan J. , Setescak Linda L. , Van Engen Donna 
Published: April 2009

Abstract1,2,3,4‐Tetrahydrobenzo[c]‐1,5‐naphthyridine (5a) was prepared by a novel synthetic route involving the rearrangement of (±)‐(Z)‐1,10a‐dihydropyrrolo[1,2‐b]isoquinoline‐3,10(2H,5H)‐dione oxime to afford 1,4‐dihydrobenzo[c]‐1,5‐naphthyridin‐2(3H)‐one, which was reduced to 5a. The cholinomimetic activity observed with 5a prompted the synthesis and biological evaluation of additional analogues.
The reaction of 6‐halopurines with phenyl metal complexes
Authors: McKenzie Thomas C. , Glass Debbie 
Published: April 2009

AbstractThe reaction of N‐alkyl‐6‐halopurines and phenyl lithium in the presence of various transition metal catalysts was investigated. The 6‐chloro compounds were found to react at C‐8 to give both addition and substitution products. The C‐8 substitution reaction was found to be photo stimulated, and it is likely that it procedes by an electron transfer mechanism. A 6‐iodopurine was found to react with lithium diphenyl cuprate to give 6‐phenylpurine in good yield.
Synthesis and reaction of 6‐substituted 3‐methoxycarbonyl‐4‐methylthio‐2H‐pyran‐2‐one derivatives
Authors: Tominaga Yoshinori , Ushirogochi Atsuyuki , Matsuda Yoshiro 
Published: April 2009

AbstractReaction of aryl and styryl methyl ketones1a‐mwith dimethyl bis(methylthio)methylenemalonate (2) in the presence of potassium hydroxide in dimethyl sulfoxide gave the corresponding methyl 6‐aryl‐ and 6‐styryl‐4‐methylthio‐2‐oxo‐2H‐pyran‐3‐carboxylates3a‐m.6‐Aryl derivatives3a‐d,gwere treated with sodium methoxide in methanol to give the corresponding 6‐aryl‐4‐methoxy‐2H‐pyran‐2‐ones8a‐dand9.Phenylcoumalin (7a) and paracotoin (7b) were synthesized by the desulfurization of 6‐aryl‐4‐methylthio‐2H‐pyran‐2‐ones4a,b.Similarly, anibine (8e) was also synthesized from3g.Treatment of3with hydrogen peroxide or 3‐chloroperoxybenzoic acid gave the corresponding 4‐methylsulfiny‐2H‐pyran‐2‐ones10a‐fin good yields. Displacement reactions of10a‐fwith nucleophilic reagents are also described.
A facile synthesis of the 1,3‐dithiolo[4,5‐b]pyridine ring system via pyridylthiocyanates
Authors: Chen Ted K. , Flowers William T. 
Published: April 2009

Abstract2‐Chloro‐3‐thiocyanatopyridine reacted with thioacetic acid and thiobenzoic acid to yield 2‐acetylimino‐1,3‐dithiolo[4,5‐b]pyridine and 2‐benzoylimino‐1,3‐dithiolo[4,5‐b]pyridine respectively. 2,5,6‐Trihalo‐3‐thiocyanatopyridine under the same conditions gave only the corresponding 3‐S‐acetyl‐3‐thio or 3‐S‐benzoyl‐3‐thiopyridine.
Total synthesis of symmetric bile pigments: Mesobilirubin‐IVα, mesobilirubin‐XIIIα and etiobilirubin‐IVγ
Authors: Trull Francesc R. , Franklin Roger W. , Lightner David A. 
Published: April 2009

AbstractThe unnatural bile pigments mesobilirubin‐IVα, mesobilirubin‐XIIIα and etiobilirubin‐IVγ were synthesized following self‐coupling of the pyrromethenones ψ‐xanthobilirubic acid methyl ester, xanthobilirubic acid methyl ester and kryptopyrromethenone, respectively.
The chemistry of polycyclic arene imines. VII. Reactions of phenanthrene 9,10‐imine with aromatic carboxaldehydes, carboxylic acids and acetylenic esters
Authors: Shtelzer Sarah , Sheradsky Tuvia , Blum Jochanan 
Published: April 2009

AbstractThe reactions of phenanthrene 9,10‐imine (1) with aromatic aldehydes, benzoic acids and acetylenedi‐carboxylic esters were investigated. The aldehydes were shown to give 1‐[N‐(arylmethylidene)‐9‐phenanthreneamine‐10‐yl]‐1a,9b‐dihydrophenanthro[9,10‐b]azirine 2. The ‘dimeric’ structure of these products was established by X‐ray diffraction analysis. The carboxylic acids proved to form in the presence of dicyclohexylcarbodiimide, N‐aroylphenanthrene 9,10‐imines 7, that readily undergo rearrangement to N‐aroyl‐9‐phenanthrenamines 8. Esters of acetylenedicarboxylic acid gave the corresponding esters of (Z)‐2‐(1a,9b‐dihydrophenanthro[9,10‐b]azirine‐1‐yl)‐2‐butendioic acid 10.
Synthesis and structure of 6‐ and 7‐(2‐arylvinyl)pteridines
Authors: Abdel‐Hady Sayed A. L. , Badawy Mohamed A. , Kadry Azza M. , Mosselhi Mosselhi A. N. 
Published: April 2009

Abstract7‐Hydroxy‐6‐styrylpteridine 9 and 7‐(2‐arylvinyl)‐6‐hydroxypteridines 10–12 were synthesized via the condensation of 5,6‐diaminouracil 1 with benzylidenepyruvic acids 2–4. The synthesis of the 2‐methylthio analogue 15 is also described.
An improved synthesis of 3‐(1‐imidazolyl)‐2‐alkenoic acid derivatives and related compounds
Authors: Kashima Choji , Yoshiwara Nobutoshi , Tajima Tadakuni , Omote Yoshimori 
Published: April 2009

AbstractThe preparative method of 3‐(1‐imidazolyl)‐2‐alkenoic acid derivatives and the related compounds was improved by the use of strong bases such as sodium hydride in DMF. By this improved method, the preparation of 2‐substituted 3‐(1‐imidazolyl)‐2‐alkenoic acid derivatives was accomplished in good yields.
Synthesis and antifungal activity of some allylamine derivatives
Authors: Bandiera Tiziano , Albini Franca Marinone , Albini Enrico 
Published: April 2009

AbstractBenzo‐ and mesitonitrile oxides react with allylamine to yield 5‐aminomethyl‐2‐isoxazolines and open‐chain N‐substituted amidoximes. The allylamine derivatives were evaluated as potential antifungal and antibacterial agents. The N‐allylbenzamidoxime 2a was found to be only moderately active against dermatophytes.
Reactions with 2‐mercaptopyrimidines. Synthesis of some new thiazolo[3,2‐a]‐ and triazolo[4,3‐a]pyrimidines
Authors: Hussain S. M. , El‐Reedy A. M. , Rezk A. M. Hassan , El‐Dien Kh. A. Sife 
Published: April 2009

AbstractAlkylation of 5‐cyano‐4‐oxo‐6‐phenyl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidine I with methyl iodide, chloroacetic acid or 3‐chloro‐2,4‐pentanedione, afforded the S‐alkyl derivatives IIa‐c. 2‐Carboxymethylthio and 2‐(2′,4′‐dioxopentan‐3‐ylthio) derivatives IIb and IIc could be cyclised by acetic anhydride or polyphosphoric acid to give 6‐cyano‐3,5‐dioxo‐5H‐7‐phenylthiazolo[3,2‐a]pyrimidine III and 2‐acetyl‐6‐carboxamido‐5H‐3‐methyl‐7‐phenylthiazolo[3,2‐a]pyrimidine‐5‐one IX, respectively. Benzoylation of 2‐hydrazinopyrimidine derivative XII, in anhydrous dioxan, afforded the N‐benzoyl derivative XIII, which could be cyclised by heating in dimethylformamide to give 5‐amino‐6‐cyano‐3,7‐diphenyl‐s‐triazolo[4,3‐a]pyrimidine (XIV). The 2‐hydrazinopyrimidine derivatives XII and XV reacted with benzoyl isothiocyanate in dioxane to yield 4‐benzoylthiosemicarbazide derivatives XVI and XVII, which were converted into the 2‐s‐trizolopyrimidine derivatives XVIII and XIX, respectively. Also, XVI and XVII reacted with 2,4‐pentanedione and 3‐chloro‐2,4‐pentanedione to yield 2‐pyrazolopyrimidine derivatives XX and XXI, respectively.
The synthesis of some 2,4‐disubstituted derivatives of quinolone‐3‐carboxylic acids and carbonitriles
Authors: Leysen D. L. , Haemers A. , Bollaert W. , Dommisse R. A. , Esmans E. L. 
Published: April 2009

AbstractIn order to prepare the 2‐chloro derivative of oxolinic acid, ethyl 1‐ethyl‐1,4‐dihydro‐2‐hydroxy‐6,7‐methylenedioxy‐4‐oxo‐3‐quinolinecarboxylate was treated with phosphorus oxychloride. The compound obtained was the 4‐chloro‐2‐oxo‐quinoline. The structure was confirmed by 13C nmr and mass spectral techniques. The 2‐halocarbonitrile was obtained by a Sandmeyer reaction but could not be hydrolysed into the acid.
Synthèse et étude structurale de dérivés substitués en ‐2 du thiazolidine carboxylate d'éthyle‐4 (R)
Authors: Hamri Abdesselam , Péra Marie‐Hélène , Fillion Houda 
Published: April 2009

AbstractDes dérivés de la thiazolidine carboxylate d'éthyle‐4(R) sont obtenus sous la forme d'un mélange de diastéréoisomères dont le pourcentage est modifié par addition d'acide trifluoroacétique.
P‐N compounds. 30. Phosphaminimides. 5. N‐phosphinylimino‐1,2,5,6‐tetrahydropyridines
Authors: Cates Lindley A. , Li Ven‐Shun 
Published: April 2009

AbstractN‐[ (Diethoxyphosphinyl)imino] and N‐[ (diphenylphosphinyl)imino]‐5‐methyl‐1,2,5,6‐tetrahydropyridines were prepared by sodium borohydride reduction of the corresponding pyridinium and 3‐methyl pyridinium inner salts. The carbonyl analog of this latter precusor was resynthesized and its structure completely verified.
A facile retro‐ene reaction of 5‐(methoxyamino)‐3‐aryl‐1,3,4‐oxadiazol‐2(3H)‐ones
Authors: Kleier Daniel A. , Pilgram Kurt H. 
Published: April 2009

Abstract5‐(N‐Methoxy‐N‐methyl)amino‐3‐aryl‐1,3,4‐oxadiazol‐2(3H)‐ones3undergo a heteroretro‐ene reaction in refluxing methanol in which the leaving enophile is formaldehyde. The resulting 5‐(methylimino)‐3‐aryl‐1,3,4‐oxadiazolidin‐2‐one4may be viewed as a kinetic product which tautomerizes to the more stable 5‐(methylamino)‐3‐aryl‐1,3,4‐oxadiazol‐2(3H)‐one5as the thermodynamic product. Comparison of calculated reaction energies reveals that the presence of the heterocyclic ring facilitates the retro‐ene reaction, but the expulsion of formaldehyde is predicted to be highly exothermic even in its absence.
On the nitro group transfer from 2‐nitro‐4,5,6,7‐tetrachloro‐2H‐benzotriazole and 2‐nitro‐2H‐phenanthro[9,10‐d]triazole to secondary amines
Authors: Cohen‐Fernandes Pauline , Habraken Clarisse L. 
Published: April 2009

AbstractThe synthesis of 2‐nitro‐4,5,6,7‐tetrachloro‐2H‐benzotriazole 1 and of 2‐nitro‐2H‐phenanthro[9,10‐d]‐triazole 2 and their transfer of the nitro group to give 1‐nitropyrrolidine 4a and 1‐nitromorpholine 4b in high yields when reacted with pyrrolidine or morpholine are reported. The reaction of 1 also gives the pyrrolidinium and morpholinium salts 5a‐b of 1.
Chemistry of C‐heteroarylnitrilimines. Synthesis and cycloaddition reactions of N‐phenyl‐C‐(2‐thienyl)nitrilimine
Authors: Hassaneen Hamdi M. , Mousa Hiyam A. H. , Shawali Ahmad S. 
Published: April 2009

AbstractThe nitrilimine 7, generated in situ from N‐phenyl‐C‐(2‐thienyl)formohydrazidoyl chloride 5 in chloroform in the presence of triethylamine, reacts with acrylonitrile, acrylamide and arylidene acetophenones to give exclusively the 5‐substituted 2‐pyrazoline derivatives 9, 10 and 16, respectively. On the other hand, the cycloaddition of 7 to coumarin, benzalmalononitrile and the enolate anions of active methylene compounds yield the pyrazole derivatives 12, 14 and 23, respectively. The structures of the cycloadducts prepared were attributed on the basis of spectroscopic and chemical evidence. The regioselectivity in the studied reactions is discussed in terms of the frontier orbital theory.
Synthesis of 2,4‐(1H,3H)‐quinazolinediones
Authors: Hammen Philip D. , Allen Douglas J. M. 
Published: April 2009

AbstractImproved procedures for syntheses of kilogram quantities of quinazolinedione 5 and its intermediates 2,3 and 4 are described. The mechanism of formation of 5 is discussed as well as a side reaction resulting in 7.
Synthesis of 3‐benzoyl‐3,4‐dihydro‐2H‐ and 3,4‐dihydro‐2,2‐disubstituted‐benzopyrans via alkynyl grignard reagents
Authors: Adegoke Emmanuel A. , Emokpae T. A. , Ephraim‐Bassey H. , Oyelola C. A. 
Published: April 2009

AbstractThe versatility of the new route to a substituted chromane via a lithiated allene recently described by us [1] is reported. The relatively more stable alkynols 2–4 were readily identified and thus provide evidence for the formation of vinyl acetylene carbinol as an intermediate in the new route. Accordingly, phenylacetylene magnesium bromide [2] reacted with suitable aldehyde or ketone to give the alkynols 2–4 which condensed further with the same or different aldehyde or ketone to give 3‐benzoyl heteroring‐substituted chromanes 5–17.
Reaction of 5‐hydroxy‐L‐tryptophan with alkyl isocyanates
Authors: Braña Miguel F. , Garrido Mercedes , Hernando José L. , Rodríguez María L. LÓPez , Morcillo M. José 
Published: April 2009

Abstract5‐Hydroxy‐L‐tryptophan 4 with potassium cyanate gives 5‐(5‐hydroxy‐3‐indolylmethyl)hydantoin 5 or Nb‐carbamoyl‐5‐hydroxy‐L‐tryptophan 6 depending on the reaction conditions. Reaction of 4 with methyl iso‐cyanate in acetone provides 5‐hydroxy‐Nb‐methylcarbamoyl‐L‐tryptophan 7. Treatment of 4 with ethyl, propyl and isopropyl isocyanates in acetone gives rise to the formation of the corresponding 2‐[(3‐alkyl‐4,4‐dimethyl‐2‐oxo)‐1,3‐diazetidinyl]‐3‐(5‐hydroxy‐3‐indolyl)propionic acids 8–10.
Reversible formation of cyclic 1,4‐benzothiazine oligomers
Authors: Chioccara Francesco , Novellino Ettore 
Published: April 2009

Abstract1,4‐Benzothiazine 2, generated in situ by mild hydrolysis of aminoacetal 3, readily undergoes aldolization to give mainly two pairs of diastereoisomeric trimers and tetramers, having the gross structure 5 and 6 respectively. In strongly acidic media the oligomers are depolymerized to give monomeric 2H‐1,4‐benzothiazine (1H nmr evidence) which, at slightly acidic or neutral pH, is converted to a mixture of the same trimers and tetramers. These results provide an improved background to look into the biosynthesis of phaeomelanins which are known to originate by polymerization of 1,4‐benzothiazine intermediates.
Cyclization of diketones to pyridazine and furan derivatives
Authors: Allah Hassan M. Faid , Soliman Raafat 
Published: April 2009

AbstractCondensation of (±)‐2,3‐bis(3,4‐dimethoxybenzoyl)butane‐1,4‐dione 1 with different hydrazine bases afforded the corresponding pyridazines 2 and 3. Refluxing the diketone 1 with methanolic hydrogen chloride yielded the corresponding 3,4‐dimethylfuran derivative 5. Reaction of acetonylacetone 6 with p‐sulfamylphenylhydrazine afforded the corresponding 3,6‐dimethyl‐1H‐pyridazine derivative 7. Reaction of 7 with the appropriate isocyanate and isothiocyanate yielded the corresponding benzenesulfonylurea 8 and thiourea 9 derivatives respectively. The structures of the compounds synthesized were affirmed by microanalyses and spectral studies.
Reaction of t‐butyl lithium with (±)‐3‐methoxy‐N‐chloromorphinan
Authors: Mohacsi Erno , Yang Roxana , Blount John 
Published: April 2009

AbstractPreparation of (±)‐3‐methoxy‐16‐t‐butylmorphinan (4) by reaction of t‐butyl lithium with (±)‐3‐methoxy‐N‐chloromorphinan (1) is described. The structure of 4 was confirmed by X‐ray crystallography.
Thiazolidinethiones vs. imidazolidinedithiones as products from cyanothioformanilides and phenyl isothiocyanates
Authors: Huang Jamin , Graves Michael D. 
Published: April 2009

AbstractThe formation of thiazolidinethiones 3 and/or imidazolidinedithiones 5 from cyanothioformanilides and aryl isothiocyanates is found to be dependent upon the type of bases used, reaction temperature and the nature and position of substituents on cyanothioformanilides. Examples are presented.
Studies in the furan series. 23. Preparation of some new 5‐substituted furfurylallylarylamines. Influence of substituents on the intramolecular Diels‐Alder (IMDA) reaction
Authors: Klepo Ž. , Jakopčić K. 
Published: April 2009

AbstractSeveral new N‐allyl‐N‐(5‐substituted)‐2‐furfuryl‐p)‐toluidines IIIa‐e with Cl, Br, I, NO2 or CH3O groups in position 5 of the furan nucleus were prepared by allylation of the corresponding secondary furfurylaryl‐amines. Both, electron withdrawing and releasing substituents enhanced the yield of intramolecular [4+2] cycloaddition.
Synthesis of arylsulfonyl substituted pyrroles
Authors: Dalla Croce Piero , Gariboldi Pierluigi , La Rosa Concetta 
Published: April 2009

AbstractThe cycloaddition reaction of symmetrically and unsymmetrically substituted munchnones with arylsulfonyl alkynes has been studied. The reaction affords pyrrole derivatives whose structures were assigned on the basis of spectroscopic data. The distribution of regioisomers observed in the case of unsymmetrically substituted munchnones is discussed.
Pyrrole reduction: The zinc/acid reduction of octahydrocarbazoles
Authors: Anderson‐McKay Janet E. , Lawlor John M. 
Published: April 2009

AbstractThe stereo‐ and regiochemical course of the zinc/acid reduction of 1,2,3,4,5,6,7,8,‐octahydrocarbazole is strongly influenced by experimental conditions and by the nature of the N‐substituent.
Transformations of N‐heteroarylformamidines into derivatives of β‐heteroarylamino‐α,β‐dehydro‐α‐amino acids, β‐heteroarylamino‐α‐amino acids, and dipeptides
Authors: Stanovnik Branko , Svete Jurij , Tišler Miha 
Published: April 2009

AbstractTransformations of N'‐heteroaryl‐N,N‐dimethylformamidines 1 as a general method for the preparation of β‐heteroarylamino‐α,β‐dehydro‐α‐amino acids, β‐heteroarylamino‐α‐amino acid derivatives 5–9, and dipeptides 10, are described.
A conformational analysis of the six isomers of bipyridinium dication
Authors: Von Nagy‐Felsobuki Ellak I. 
Published: April 2009

AbstractThe conformational analysis of the bipyridinium dications have been investigated using ab initio STO‐3G calculations in which the inter‐ring bond length was optimized at each torsional angle. The variation of the inter‐ring separation has been rationalized using a heuristic valence bond model (which is electrostatic in nature) and which was suggested by the molecular orbital calculations. Furthermore, all six isomers show a double potential minima at the optimium torsional angles of ∼ 50° and ∼ 130° respectively. Moreover, all barrier heights are calculated to be less than 8 kJ mol−1, thereby suggesting that the barrier heights are not large enough to prevent rapid interconversion between different rotamers.