bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effective methods for the syntheses of 2‐pyrazolines and pyrazoles from diazocarbonyl compounds
Authors: Doyle Michael P. , Colsman Mark R. , Dorow Roberta L. 
Published: March 2009

AbstractDipolar addition of diazocarbonyl compounds to α,β‐unsaturated esters and nitriles in the presence of pyridine results in the production of 2‐pyrazolines in nearly quantitative yields. In one case, reaction of α‐diazoacetophenone with acrylonitrile, Michael addition of the 2‐pyrazoline to the conjugated olefin is observed, but this process is minimized by limiting the amount of pyridine employed. 5‐Cyano‐2‐pyrazolines are converted to derivative pyrazoles through alkoxide promoted hydrogen cyanide elimination. With vinyl sulfone, α‐diazoacetophenone undergoes sequential dipolar addition, Michael addition, and vinyl sulfite elimination under exceptionally mild conditions to form the derivative β‐(1‐pyrazolyl)ethyl vinyl sulfone in good yield.
4,5,8,9‐tetrahydro‐8‐methyl‐9‐oxothieno[3′,2′:5,6]cyclohepta[1,2‐b]‐ pyrrole‐7‐acetic acid. A new anti‐inflammatory/analgesic agent
Authors: Goudie A. C. , Rosenberg H. E. , Ward R. W. 
Published: March 2009

AbstractThe synthesis of the thienocyclohepta[1, 2‐b]pyrrole acid 1 from the morpholide 3 is reported. This novel morpholide was prepared by regiospecific alkylation of the dianion of 4‐(1, 3‐dioxobutyl)morpholine with 3‐bromomethylthiophene. Subsequent Knorr pyrrole synthesis led to the morpholide 8b which was converted to the desired tricyclic ring system under Vilsmeier conditions. An alternative route involving Friedel‐Crafts cyclisation was used to prepare the related benzocycloheptapyrrole 2.
Réactions entre l'indole et les chlorures d'acides, en milieu basique: Synthèse d'amides de l'ortho [bis(indolyl‐3)]‐2 éthyl, aniline
Authors: Bourgeois Paul , Mesdouze Jean , Philogène Emile 
Published: March 2009

AbstractLes chlorures d'acides réagissent avec l'indole en milieu aqueux basique et conduisent à des amides secondaires de l'ortho, [bis(indolyl‐3)]‐2 éthyl, aniline. Leur formation peut ětre envisagée comme suit: autocondensation de l'indole pour donner (l'indolyl‐3)‐2 dihydro‐2, 3 indole; acylation de ce composé au niveau de l'azote du cycle saturé; attaque d'une nouvelle molécule d'indole sur le sommet 2 du dérivé formé précédemment acompagnée de l'ouverture du cycle portant la fonction amide.
Synthesis of Benzofuro[3,2‐e][1,4]diazepines
Authors: Gatta Franco , Settimj Guido 
Published: March 2009

AbstractA synthesis of 4‐N‐oxides and of 3‐hydroxy derivatives of 1,3‐dihydro‐2H‐benzofuro[3,2‐e][1,4]diazepin‐2‐ones and of 2,3‐dihydro‐1H‐benzofuro[3,2‐e][1,4]diazepines is described. Condensation of 2‐acetyl‐ and 2‐benzoyl‐3‐ethoxycarbonylaminobenzofurans with acrylonitrile gave derivatives of 1,2‐dihydro‐ and of 1,2,3,4‐tetrahydrobenzofuro[3,2‐b]pyridine.
Cycloaddition of dimethyl acetylenedicarboxylate to indoles. Isolation of a [2 + 2] adduct
Authors: Augusto J. , Rodriguez R. , Verardo L. I. 
Published: March 2009

AbstractThermal reaction of 1,2,3‐trimethylindole (1) and 1,3‐dimethylindole (5) with dimethyl acetylenedicarboxylate in the presence of boron trifluoride etherate gave cyclobutene derivatives 2 and 7 that were isolated for the first time in good yields under themal conditions. In a polar solvent and with an excess of catalyst, 4‐methoxy‐2,4a‐dihydro‐4a,9‐dimethyl‐2‐oxacarbazole 4 was obtained in yields up to 72%.
Synthesis of some alkyl‐ and arylimidazoles
Authors: Watanabe T. , Nishiyama J. , Hirate R. , Uehara K. , Inoue M. , Matsumoto K. , Ohta A. 
Published: March 2009

AbstractThe pyrolysis of 2‐azidopyrazines led to give 1‐cyanoimidazoles, which were hydrolyzed in alkaline and acidic media to the corresponding imidazoles. This ring transformation occurred also by photolysis.
Activated nitriles in heterocyclic synthesis. A novel synthesis of pyrazine derivatives
Authors: Khalifa Mohamed Ali Elsayed , Zayed Ezzat Mohamed , Mohamed Mona Hassan , Elnagdi Mohamed Hilmy 
Published: March 2009

AbstractA novel synthesis of pyrazine derivatives from the reaction of α‐tosyloximinonitriles with several active methylene enaminonitrile derivatives is reported. The reaction sequence is discussed.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (isatoic anhydride). 12. Synthesis of araliopsine and isoplatydesmine
Authors: Coppola Gary M. 
Published: March 2009

AbstractN‐Methylisatoic anhydride reacts with the lithium enolate derived from 3,3‐dimethyloxiranepropanoic acid ethyl ester (7) to initially produce the acyclic β‐ketoester 8. Under neutral conditions, 8 spontaneously cyclizes to the alkaloid araliopsine (1a). In the presence of acid, 8 cyclizes to a mixture of 1a and its leanear isomer isoplatydesmine (2a).
13C NMR spectral characterization of epimeric rotenone and some related tetrahydrobenzopyranofurobenzopyranones
Authors: Abidi S. L. , Abidi M. S. 
Published: March 2009

AbstractThe 13C nuclear magnetic resonance (nmr) spectra of epimers of rotenone and four 12a‐hydroxy‐analogues were examined to determine the stereochemical effect of the B/C ring fusion involving the 6a‐ and 12a‐carbon centers. Chemical shift differences between the epimeric carbon resonances of cis‐ and trans‐6a,12a‐compounds were notably larger than those of diastereoisomers derived from the same B/C ring junction stereochemistry. Results of the spectral analysis have been useful for the quantification of mixtures of epimers and for the measurement of rates of epimerization and oxygenation.
Synthesis of 1,2,4‐triazoles and 1,2,4‐oxadiazoles
Authors: Lin Yang‐I , Hlavka Joseph J. , Bitha Panayota , Lang S. A. 
Published: March 2009

AbstractMonothiodiacylamines reacted regiosepecifically with hydrazines and hydroxylamine to give substituted 1,2,4‐triazoles and 1,2,4‐oxadiazoles in excellent yields.
Reaction of 4‐Amino‐1,2,4‐triazines with phosphorus pentasulfide. Deamination during aromatization
Authors: Eid M. M. , Badawy M. A. , Ghazala M. A. H. , Ibrahim Yehia A. 
Published: March 2009

AbstractSynthesis of several derivatives of thieno[2,3‐e]‐1,2,4‐triazines has been achieved via the action of phosphorus pentasulfide on 6‐vinyl‐ or 6‐acylmethyl‐5‐oxo‐1,2,4‐triazine derivatives. During these investigations interesting synthetically useful functions for phosphorus pentasulfide in pyridine were observed, among which the deamination of certain N‐amino heterocycles is unprecedented.
Chemistry of thienopyridines. XXX. Elaboration of the substituent in 6‐cyanothieno[2,3‐b]pyridine
Authors: Klemm L. H. , Muchiri Daniel R. 
Published: March 2009

AbstractTen derivatives of thieno[2,3‐b]pyridine bearing substituents at the 6‐position are obtained from transformations which start with 6‐cyanothieno[2,3‐b]pyridine (2). Treatment of 2 with sodium alkoxide‐alkanol gives imidates (3) in ca. 85% yield. Methyl imidate 3a reacts, in turn, with ammonium chloride to produce a carboxamidine (84%), with 1,ω‐alkyldiamines to form cyclic amidines, and with Meldrum's acid to give an aminoester intermediate (4) (36%). Various reagents then convert 4 into the acetyl derivative (86%) (also obtained directly from 2), an unsaturated aminoester (6) (80%), and a β‐ketoester (7) (39%). Spectral data are reported for these compounds.
Improvement in the synthesis of N,N'‐diacyl‐1,2‐di(4‐pyridyl)ethylenediamines
Authors: Braña M. F. , Castellano J. M. , Rodriguez M. L. López 
Published: March 2009

AbstractA better synthetic route to pharmacologically active N,N'‐diacyl‐1,2‐di(4‐pyridyl)ethylenediamines is described.
Ester, amide and ether derivatives of 1‐(p‐phenyl‐substituted)‐1,2,3‐triazoles
Authors: Livi Oreste , Biagi Giuliana , Ferrarini Pier Luigi , Primofiore Gianpaolo , Mori Claudio 
Published: March 2009

AbstractThis paper describes the preparation of three series of 1‐phenyl‐1,2,3‐triazol derivatives with an ester, amide or ether group on the phenyl ring. These derivatives were obtained from 4‐hydroxyphenyl‐ and 4‐aminophenyltriazoles, previously synthesized by us, by means of a nucleophilic substitution reaction with acetic anhydride, acyl and alkyl halides. The largest part of compounds were tested in an agricultural chemicals, nutrition and animal health screening programme.
Interaction of alkali metals with unsaturated heterocyclic compounds. The reductive metalation of 1,4‐diphenylphthalazine
Authors: Kaban Seniz 
Published: March 2009

Abstract1,4‐Diphenylphthalazine (1) was reduced in tetrahydrofuran by sodium metal to a monomeric dianion 2. Chemical reactions of this new dianion were examined with various reagents. Generally, the protonation, acylation and alkylation products were 1,2‐dihydrophthalazine derivatives. An annulation of the phthalazine ring system was accomplished by treating the dianion with 1,3‐dichloropropane or 1,4‐dichlorobutane. With 1,2‐dichloroethane however, only 1,4‐diphenylnaphthalene was detected.
Reaction of 4‐thioxo‐1,3‐benzothiazines with thiocarbohydrazine: Synthesis and reactivity of 1,3,4‐triazolo[3,2‐c]quinazoline derivatives
Authors: Molina P. , Arques A. , Cartagena I. , Valcarcel M. V. 
Published: March 2009

Abstract2‐Aryl‐4‐thioxo‐1,3‐benzothiazines react with thiocarbohydrazide to give the new mesoionic compounds an‐hydro 1‐amino‐5‐aryl‐2‐mercapto‐1,3,4‐triazolo[3,2‐c]quinazolin‐4‐ium hydroxides. These compounds react with methyl iodide, aldehydes and phenacyl bromides to give 1‐amino‐5‐aryl‐2‐methylthio‐1,3,4‐triazolo‐[3,2‐c]quinazolin‐4‐ium iodides, 4‐arylidenamino‐3‐(o‐aroylamino)phenyl‐1H‐1,2,4‐triazolin‐5‐thiones and 3‐(o‐aroylamino)phenyl‐6‐aryl‐7H‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazines, respectively. These latter compounds by sequential treatment with methyl trifluoromethanesulphonate and triethylamine lead to 3‐(o‐aroylamino)‐phenyl‐6‐aryl‐1‐methyl‐7‐mercapto‐1H‐pyrazolo[5,1‐c]‐1,2,4‐triazoles.
Investigation of the reactions of fluorinated isatins and N‐acetylisatins with thiocarbohydrazide: Synthesis of a novel spiro system: 2‐oxo‐1′,2′,4′,5′‐tetrahydrospiro[3H‐indole‐3,3′‐1,2,4,5‐tetrazine]‐6′‐thione
Authors: Joshi Krishna C. , Jain Renuka , Dandia Anshu , Sharma Vandana 
Published: March 2009

AbstractA novel system 2‐oxo‐1′,2′,4′,5′‐tetrahydrospiro[3H‐indole‐3,3′‐1,2,4,5‐tetrazine]‐6′‐thione has been synthesized by the treatment of fluorinated isatins with thiocarbohydrazide in aqueous ethanolic medium. Under exactly similar conditions, N‐acetylisatin gave exclusively thiocarbohydrazone. The spiro product, on treatment with acetic acid, gave fluorinated isoindigo. Characterization of these products have been done by elemental analyses, ir, pmr and mass spectral studies.
Studies on pyrazines. 13. Chlorination of 1‐hydroxy‐2(1H)‐pyrazinones with phosphoryl chloride. Formation of 2,5‐dichloro‐3‐phenylpyrazine from 1‐hydroxy‐3‐phenyl‐2(1H)‐pyrazinone
Authors: Sato Nobuhiro 
Published: March 2009

AbstractThe chlorination of 1‐hydroxy‐3‐phenyl‐2(1H)‐pyrazinone with phosphoryl chloride proceeded to 5‐chloro‐3‐phenyl‐2(H)‐pyrazinone or 2,5‐dichloro‐3‐phenylpyrazine on heating to elevated temperatures. To define the mechanism of the novel formation, reactions of the parent or methyl‐substituted 1‐hydroxy‐2(1H)‐pyraz‐inones with the same reagent were investigated.
A short synthesis of praziquantel
Authors: Yuste Francisco , Pallás Yadira , Barrios HÉCtor , Ortíz Benjamín , Sánchez‐Obregón Rubén 
Published: March 2009

AbstractThe synthesis of praziquantel (1), a potent anthelmintic agent, is reported. The synthesis requires five steps and proceeds in 16% yield.
Natural abundance 17O NMR spectroscopy of heteroaromatic Nitro compounds
Authors: Balakrishnan Pattabiraman , Boykin David W. 
Published: March 2009

AbstractThe 17O chemical shift data, at natural abundance, for selected nitroquinolines, nitroindoles, nitroindazoles and nitrothiophenes are reported. In the absence of a peri or a lone‐pair repulsion effect, the nitroquinolines' chemical shifts differ little from those of their carbocyclic analogs. However, the signal for 5‐nitroquinoline, 2, is deshielded by 25 ppm compared to 6‐nitroquinoline, 1, and the 17O nucleus in 8‐nitroquinoline, 3, is deshielded by 49 ppm compared to that in 1. Both these shifts are attributed to rotation of the nitro group from the plane of the heteroaromatic ring arising from peri hydrogen interaction and lone pair repulsion, respectively. The signals for nitro groups on electron excessive ring systems (e.g., indoles and thiophenes) are shielded relative to corresponding ones in electron deficient heterocyclic ring system analogs. The chemical shifts for the π‐excessive systems are interpreted in terms of electronic effects.
Stereo structures and absolute configurations of reaction products of dl‐1,3‐dimethylthymine epoxide with l‐amino acid ethyl esters
Authors: Harayama Takashi , Yanada Reiko , Taga Tooru , Machida Katsunosuke , Yoneda Fumio 
Published: March 2009

AbstractEach reaction of dl‐1,3‐dimethylthymine epoxide (1) with L‐amino acid ethyl esters (Pro‐OEt, Met‐OEt, Phe‐OEt, and Trp‐OEt) afforded the respective four optically active diastereomers 4–7, stereo structures of which were definitely elucidated as shown in Chart 1 by an X‐ray analysis of 4A and chemical means.
Asymmetric alkaloid synthesis from (S)‐pyroglutamic acid. I. Synthesis of (S)‐5‐ethyl‐2‐pyrrolidinone
Authors: Marco José L. 
Published: March 2009

AbstractFrom (S)‐pyroglutamic acid (1) the asymmetric synthesis of (S)‐5‐ethyl‐2‐pyrrolidinone (5) in 30% yield is described.
Réaction d'imidoylation: Réactivité de composés à méthylène actif avec les O‐ethylcarbamates cycliques
Authors: Huché Michel , Lhommet Gérard 
Published: March 2009

AbstractLes synthèses des α‐(tétrahydroxazole‐1,3 ylidène‐2) et α‐(tétrahydroxazine‐1,3 ylidène‐2) malodinitriles, cyanacétates d'éthyle, et malonates d'isopropylidène sont rapidement réalisées par condensation des malodinitrile, cyanacétate d'éthyle ou malonate d'isopropylidène sur divers O‐éthyl carbamates cycliques.
Studies on biologically active heterocycles. Part I. Synthesis and antifungal activity of some new aroyl hydrazones and 2,5‐disubstituted‐1,3,4‐oxadiazoles
Authors: Dutta M. M. , Goswami B. N. , Kataky J. C. S. 
Published: March 2009

AbstractA series of new 1‐(2,4‐dichlorobenzoyl) hydrazones and 2‐aryl/aralkyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazoles have been synthesized from 2,4‐dichlorobenzoylhydrazine and different aldehydes. Subsequent ring closure of the substituted aroyl hydrazones yielded the 1,3,4‐oxadiazoles. All the compounds were characterized by their sharp melting point, microanalysis, ir, 1H nmr and mass spectra and screened for their fungitoxic properties against Alternaria tenuis and Curvularia verruciformis. A few of the compounds showed good activity.
Alkyl nitrate nitration of active methylene compounds. Nitration of 2‐substituted 2‐oxazolines
Authors: Feuer Henry , Bevinakatti Hanamanthsa S. , Luo Xuan‐Gan 
Published: March 2009

Abstract2‐Alkyl‐ and 2‐aralkyl‐2‐oxazolines are readily converted to the corresponding α‐nitroalkyl‐ and α‐nitroaralkyl‐2‐oxazolines on treatment with an alkali metal amide such as potassium or sodium amide in liquid ammonia or with lithium diisopropylamide (LDA) in THF and an alkyl nitrate. Tertiary nitro compounds, such as 2‐(2‐nitro‐2‐propyl)‐4,4‐dimethyl‐2‐oxazoline (16) and 2‐(diphenylnitromethyl)‐4,4‐dimethyl‐2‐oxazoline (17) are obtained in good yield when the anions of 2‐(2‐propyl)‐4,4‐dimethyl‐2‐oxazoline (14) and of 2‐(diphenylmethyl)‐4,4‐dimethyl‐2‐oxazoline (23), generated by LDA are added to the nitrate in THF (inverse addition). The spectral data of the primary and secondary α‐nitroalkyl‐ and α‐nitroaralkyl‐2‐oxazolines reveal that they exist mostly in their dipolar structure. These compounds are readily converted to the corresponding α‐halonitro‐2‐oxazolines on treatment with potassium hypobromite or hypochlorite.
Alkylamination of pteridines by primary alkylamines ‐ potassium permanganate
Authors: Sladowska H. , Van Veldhuizen A. , Van Der Plas H. C. 
Published: March 2009

AbstractReaction of 7‐phenyl, 7‐p‐methoxyphenyl, 7‐t‐butyl‐ and 6,7‐diphenylpteridine with ethylamine and t‐butylamine in the presence of potassium permanganate leads to the introduction of the ethylamino or t‐butylamino group at C‐4 in the above‐mentioned pteridines. In the reaction of ethylamine/potassium permanganate besides the 4‐(ethylamino)pteridine derivatives 2‐amino‐3‐formytpyrazines are obtained as side‐products. In the reaction with t‐butylamine/potassium permanganate the corresponding pteridin‐4‐ones are obtained as by‐products. The 1H nmr spectroscopic studies have revealed that at room temperature ethylamine easily gives a σ‐adduct at C‐4, yielding a 4‐(ethylamino)‐3,4‐dihydropteridine derivative. t‐Butylamine, however, only gives with the pteridines addition at C‐4 at low temperature, i.e. at −40°. This adduct dissociates at room temperature. n‐Propylamine and n‐butylamine show the same behavior as ethylamine.
Preparation and reaction of isomeric formyl‐2,1‐benzisoxazoles
Authors: Phillips Brian T. , Hartman George D. 
Published: March 2009

AbstractThe novel 4‐formyl‐2,1‐benzisoxazole and 7‐formyl‐2,1‐benzisoxazole were prepared for conversion via the Hantzsch synthesis to 1,4‐dihydropyridines. The 4‐formyl derivative underwent efficient cyclization to the dihydropyridine while analogous reaction of the 7‐formyl compound has proven problematic.
Synthesis of 4‐aroyl‐5‐nitro‐1H‐imidazoles and 4‐aroyl‐5‐aminoimidazoles
Authors: Albright J. Donald , Moran Daniel B. 
Published: March 2009

AbstractThe reaction of α‐(aryl)‐4‐morpholineacetonitriles (masked aroyl anion equivalents) with N‐protected 4(5)‐bromo‐5(4)‐nitro‐1H‐imidazoles gave 4‐aroyl‐5‐nitroimidazoles which were reduced to afford 4‐aroyl‐5‐aminoimidazoles.
1,3,4‐oxadiazolin‐2‐ones from carbo‐t‐butoxyhydrazones
Authors: Baumgarten Henry E. , Hwang Deng‐Ruey , Rao T. N. 
Published: March 2009

Abstract5‐Substituted‐1,3,4‐oxadiazolin‐2‐ones 2 were synthesized by the oxidation of carbo‐t‐butoxyhydrazones 1 of aromatic aldehydes with lead tetraacetate or, preferably, iodosobenzene diacetate. In some instances 5‐acetoxy‐1,3,4‐oxadiazoles 3 were obtained along with 2. The oxidation of carboethoxyhydrazones 4 gave 2‐ethoxy‐1,3,4‐oxadiazoles 5.
Synthesis of (imidazo[1,2‐C]pyrimidin‐2‐yl)phenylmethanones and 6‐benzoylpyrrolo[2,3‐D]pyrimidinones
Authors: Danswan Geoffrey , Kennewell Peter D. , Tully W. Roger 
Published: March 2009

Abstract4‐Pyrimidinamines have been reacted with 3‐bromo‐1‐phenylpropane‐1,2‐dione to give a series of (imidazo[1,2‐c]pyrimidin‐2‐yl)phenylmethanones. The dione also reacted with ethyl amidinoacetate to yield ethyl 2‐amino‐5‐benzoylpyrrole‐2‐carboxylate which was used to prepare a series of 6‐benzoylpyrrolo[2,3‐a]pyrimidines.
Addition‐cyclisations of ethoxycarbonyl isothiocyanate with hydrazine derivatives as a source of thiadiazoles and triazoles
Authors: Kurzer Frederick , Seeker Jane L. 
Published: March 2009

AbstractEthoxycarbonyl isothiocyanate reacts additively with hydrazine, ethoxycarbonylhydrazine, as well as amino‐ and 1,2‐diaminoguanidine. Simultaneous or subsequent cyclisation of the resulting 1:1‐ or 2:1‐adducts in acidic or alkaline media yields substituted 1,3,4‐thiadiazoles or 1,2,4‐triazoles, respectively.
Intramolecular dials‐alder cyclization of N‐furfurylpropargylamines: A novel general synthesis of isoindoles
Authors: Katritzky Alan R. , Paluchowska Maria H. , Gallos John K. 
Published: March 2009

AbstractBenzotriazole mediated synthesis from furfurylamines, aldehydes and lithium acetylides readily provides high yields of N‐furfurylpropargylamines. These undergo intramolecular Diels‐Alder cyclization to give isoin‐doles, which are characterized as their Diels‐Alder reaction products with dimethyl acetylenedicarboxylate.
Synthesis of 2‐acyl‐3‐methylthiofurans from 3‐methylthio‐2‐pentene‐1,5‐dione enolates
Authors: Tinggaard M. , Hansen P. , Mogensen P. K. , Simonsen O. , Becher J. 
Published: March 2009

Abstract2‐Acyl‐3‐methylthiofurans 3 are obtained in fair yields from 3‐methylthio‐2‐pentene‐1,5‐dione enolates 1 by reaction with iodine. In a similar reaction 1‐phenyl‐3‐methylthio‐4‐nitro‐2‐buten‐1‐one gave 3‐methylthio‐2‐nitro‐5‐phenylfuran 11. In the crystalline state the 2‐benzoyl‐3‐methylthio‐5‐phenylfuran 3b showed a non‐bonded sulfur‐oxygen interaction as inferred from an X‐ray diffraction determination, with a S····O distance of 2.871(5)Å.
Condensed 1,3‐benzothiazinones. 2. Synthesis of 2‐substituted 1,2,4‐triazolo[5,1‐b][1,3]benzothiazin‐9‐ones
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Chern Ji‐Wang 
Published: March 2009

AbstractHeating 3‐amino‐2‐imino‐3,4‐dihydro‐2H‐1,3‐benzothiazin‐4‐one (1) with formic acid neat or with trimethyl orthoformate (2a) in xylene gave 1,2,4‐triazolo[5,1‐b][1,3]benzothiazin‐9‐one (3a) in 49 and 81% yields, respectively. An analogous reaction of 1 with triethyl orthoacetate (2b) and orthopropionate (2c), trifluoro‐acetic and trichloroacetic anhydride (2d,e), trichloroacetonitrile, dichloroacetyl, chloroacetyl, 2‐chloro‐propionyl, 3‐chloropropionyl, ethoxyoxalyl chloride (2f‐j) and benzoyl chloride (2k) under suitable conditions afforded a series of 2‐substituted 1,2,4‐triazolo[5,1‐b][1,3]benzothiazin‐9‐ones (3b‐k) in 59‐98% yields. Facile procedures for the preparation of 2‐hydroxy and 2‐mercapto derivative 31,m were developed by treating 1 with N,N′‐carbonyl‐ and thiocarbonyldiimidazole (21,m). The structures of all products were assigned on the bases of spectral and elemental analyses. Compound 3m was found to exist predominantly in the 2‐thioxo form.
Synthesis of 1‐hydroxy‐2H,5H‐dihydroisoxazolo[5,4‐c]quinoline. A novel heterocyclic ring system
Authors: Ruhland Béatrice , Leclerc Gérard 
Published: March 2009

AbstractThe synthesis of a new heterocyclic compound, 3a, combining a quinoline and a isoxazolol ring is described. The preparation involves cyclisation of the carbamate 14, followed by concomitant deprotection of the acidic and amino functions to give compound 3a, the stable tautomeric form of 3.
Synthesis of cycl[3.2.2]azine and benzo[g]cycl[3.2.2]azine derivatives by use of the [2 + 8] cycloaddition reaction of indolizines and dimethyl acetylenedicarboxylate
Authors: Tominaga Yoshinori , Shiroshita Yoshihide , Kurokawa Tomohiko , Gotou Hiromi , Matsuda Yoshiro , Hosomi Akira 
Published: March 2009

AbstractThe reaction of 1‐ethoxycarbonylmethylpyridinium bromides 5a‐k with nitro ketene dithioacetal, 1,1‐bis‐(methylthio)‐2‐nitroethylene (2), in the presence of triethylamine in ethanol gave the desired ethyl 2‐methyl‐thioindolizine‐3‐carboxylates 3a‐k in good yields, along with ethyl 2‐methylthio‐1‐nitroindolizine‐3‐carboxyl‐ates 4a‐d. Deesterification of 3 using sodium hydroxide in methanol followed by treatment with polyphosphoric acid gave the corresponding 2‐methylthioindolizines 5a‐d in good yields. The desulfurization of 5 with Raney‐nickel in ethanol occurs smoothly to give the 1,2,3‐unsubstituted indolizines 6a‐c (a, parent indolizine; b, 8‐methylindolzine; c, 6,8‐dimethylindolizine). Similarly, pyrrolo[2,1‐a]isoquinoline (19) was also synthesized.These indolizine and pyrrolo[1,2‐a]isoquinoline derivatives were allowed to react with dimethyl acetylene to give the corresponding cycl[3.2.2]azine and benzo[g]cycl[3.2.2]azine derivatives in good results.
Preparation and spectroscopic properties of 2‐benzothiazolyl araldehyde hydrazones
Authors: Beam Michael J. , Schulz Jeannette , Sinha Anvita , Collins Pamela , Hallenbeck Susan , Kustin Michael 
Published: March 2009

AbstractNotwithstanding its tendency toward air oxidation in solution, 2‐hydrazinobenzothiazole I reacted with aromatic aldehydes in ethanol to give the corresponding hydrazones III‐XV in high yields and analytical purity. In related examples, acylation took place under similar conditions to produce hydrazides XVI‐XX. The near‐infrared bands of the absorption spectra of the araldehyde hydrazones have been associated with charge transfer and appeared to correlate with structural elements of the compounds in a way suggesting that the charge transfer was intermolecular.
Synthesis of 2, 2′‐bithienyl derivatives
Authors: Kao Yuh‐Mei , Hwang Wen‐Shu 
Published: March 2009

AbstractA series of 2, 2′‐bithienyl derivatives were synthesized starting from the coupling of 2, 2′‐bithienyl and 2‐(2‐iodoethyl)‐1, 3‐dioxolane.