bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polycondensed heterocycles. II. A new preparative route to 11‐Oxo‐5H,11H‐pyrrolo[2,1‐c][1,4]benzothiazepine
Authors: Nacci V. , Garofalo A. , Fiorini I. 
Published: March 2009

Abstract6‐Methylthio‐10‐oxo‐5H,10H‐pyrrolo[1,2‐b]isoquinoline 11 was isolated in an attempted synthesis of 11‐oxo‐5H,11H‐pyrrolo[2,1‐c][1,4]benzothiazepine 1 from 1‐(2‐methylthiobenzyl)pyrrole‐2‐carboxylic acid chloride 9, obtained using as starting material o‐methylthiobenzyl bromide 3 and passing through 1‐(2‐methylthiobenzyl)pyrrole‐2‐carbonitrile 5, by cyclization with aluminum chloride. However the successful demethylation with sodium in dimethylacetamide of 1‐(2‐methylthiobenzyl)pyrrole‐2‐carboxyamide 12, formed by hydrolysis of nitrile 5, allowed us to prepare by another way the corresponding thiol 13 and consequently the 1‐(2‐mercaptobenzyl)pyrrole‐2‐carboxylic acid 14, which when subjected to intramolecular ring closure by CDI in place of DCC gave 1 in higher yield, 69% instead of 43%. Finally, the direct cyanation of 1‐(2‐ethoxycarbonylthiobenzyl)pyrrole 16, prepared utilizing the 1‐(2‐mercaptobenzyl)pyrrole 15 obtained by demethylation of the corresponding thioanisol 4 which was carried out as above, afforded the unexpected 1‐(2‐ethylthio‐benzyl)pyrrole‐2‐carbonitrile 17.
The insertion and extrusion of heterosulfur bridges. XVI. Synthesis of triphenyleno[1,12‐bcd:4,5‐b'c'd']dithiophene
Authors: Klemm L. H. , Hall Eliot , Cousins Lisa , Klopfenstein C. E. 
Published: March 2009

AbstractTriphenyleno[1,12‐bcd]:4,5‐b′c′d′]dithiophene (3) is synthesized in low yield (2.5% maximum) from a mixture of triphenylene (1) and triphenyleno[4,5‐bcd]thiophene or from 1 alone by means of heterogeneously catalyzed sulfur bridging by hydrogen sulfide at 500–550°. Compound 3 is characterized by spectral and other properties. Hückel molecular orbital calculations for the formation and reaction of 3 are presented.
Regio‐ and stereoselectivity of cycloadditions of C‐(Trifluoromethyl)nitrone with olefins
Authors: Tanaka Kiyoshi , Sugimoto Yasuhiko , Okafuji Yoshiaki , Tachikawa Masahiro , Mitsuhashi Keiryo 
Published: March 2009

AbstractN‐Methyl‐C‐(trifluoromethyl)nitrone (1) cycloadds with various olefins to give 2‐methyl‐3‐trifluoromethyl‐isoxazolidines. Predominant formation of 5‐substituted isoxazolidines in the cycloadditions with monosubstituted olefins is observed and this high regioselectivity is attributed to the dipole‐LUMO controlled interaction, being rationalized on the basis of molecular orbital calculation of 1. ‘Anti’‐favorable approach of 1 to olefin in the transition state is considered from the configuration of the cycloadducts, pointing out the very weak secondary orbital interaction between trifluoromethyl group and olefin‐substituents including phenyl or ester group.
Synthesis of some benzimidazole‐, pyridine‐ and imidazole‐derived chelating agents
Authors: Wahlgren Curtis G. , Addison Anthony W. 
Published: March 2009

AbstractProcedures are described for the preparation of various bidentate and potentially tridentate chelating agents. These incorporate pyridyl, benzimidazole, imidazole or phenolic moieties. Phillips condensations of carboxylic acids with o‐phenylenediamines were carried out in 4 M hydrochloric acid. Syntheses are reported for 2, 6‐bis(N′‐methylimidazol‐2′‐ylthiomethyl)pyridine, 2, 6‐bis(benzimidazol‐2′‐ylthiomethyl)pyridine, 2‐(4′‐piperidyl)benzimidazole, 2‐(3′‐piperidyl)benzimidazole, 2‐(3‐N′‐methylpiperidyl)benziinidazole, 2‐(3‐N′‐methylpiperidyl)‐N‐methylbenzimidazole, 2‐(2′‐hydroxybenzyl)benzimidazole and 2‐(2′‐hydroxyben‐zyl)N‐methylbenzimidazole. The compounds were characterized where appropriate by their mass, uv, and 1H‐nmr spectra. 2‐(2′‐Hydroxybenzyl)benzimidazole hydrochloride acts as a gelling agent in aqueous solution.
On pyrrolidine derivatives I. An efficient synthesis of 3‐substituted (2S,5S)‐pyrrolidine‐2, 5‐dicarboxylic acids
Authors: Honma Tsunetoshi , Tada Yukio , Adachi Ikuo , Igarashi Kikuo 
Published: March 2009

Abstract(2S,5S)‐3‐Alkylpyrrolidine‐2, 5‐dicarboxylic acid derivatives I were stereoselectively synthesized by means of an efficient method starting from L‐aspartic acid (1). Dieckmann reaction of 4‐benzyl 1‐t‐butyl N‐t‐butyl‐oxycarbonyl‐N‐ethoxycarbonylmethyl‐L‐aspartate (4) provided product 5 which consisted of a mixture of (2S,5S)‐ and (2R,5S)‐1‐t‐butyloxycarbonyl‐3‐oxopyrrolidine‐2, 5‐dicarboxylates in a ratio of 95:5. Treating 1‐t‐butyl 6‐ethyl 2‐L‐(t‐butyloxycarbonyl)anuno‐5‐diazo‐4‐oxoadipate (8), prepared from 1, with rhodium(II) acetate dimer also afforded a good yield of 5. The Wittig reaction of 5, followed by catalytic hydrogenation and then deprotection provided compound I.
Derivation of fluorine‐containing pyridine dicarboxylates. II. Elaboration at the 4‐position
Authors: Chupp John P. , Molyneaux John M. 
Published: March 2009

AbstractIn response to the bio‐activity found in fluorine‐containing 4‐alkyl‐3, 5‐pyridinedicarboxylates, a series of novel 4‐substituted derivatives, not directly available by Hantzsch sequences, were prepared. Starting 4‐alkylpyridines, 1, were converted via enamine 2 to materials 3–8. Derivatives 9–16 in turn were derived from aldehyde 3, while acid derivatives 28–36 were prepared from 14. Addition of oxygen, sulfur, and carbenoids effected conversion of 4‐allylpyridine 16 to epoxy and cyclopropyl derivative 16–22. A number of neighboring group effects were noted, including those forming the fused‐ring systems 23‐27.
Synthesis of 4H‐benzo[a]phenoselenazin‐4‐ones as near‐ir dyes
Authors: Ishida Tetsuya , Sakakibara Makoto , Ueno Yoshio , Hasegawa Kan‐Ichi 
Published: March 2009

AbstractThe condensation of 2‐bromo‐ or 2, 6‐dibromo‐4, 8‐bis(alkylamino)‐1, 5‐naphthoquinones with zinc 2‐amino‐benzeneselenolates gave 1, 5‐bis(alkylamino)‐4H‐benzo[a]phenoselenazin‐4‐one and the 3‐ and/or 10‐substituted compounds. These phenoselenazone derivatives absorb nearly infrared light and can be used as optical recording media for a laser beam.
Studies of benzylisoquinolines. Comparison of the reactivity of the methylene group in 1‐benzyl and 4‐benzylisoquinolines
Authors: Vaccher Claude , Berthelot Pascal , Devergnies Monique , Debaert Michel , Bonte Jean‐Paul , Viel Claude 
Published: March 2009

AbstractWhile examining the oxidation of 4‐benzylisoquinolines to the corresponding 4‐benzoylisoquinolines as well as the reactivity of these ketones towards hydroxylamine, reduction reagents and Grignard's reagents, there was found a definite difference in the behavior of the methylene group for these compounds as compared to that of papaverine (1‐benzylisoquinolines).
A simple synthesis of dimethyl 2‐pyridone‐4, 5‐dicarboxylate derivatives
Authors: Kawahara Norio , Shimamori Takako , Itoh Tsuneo , Takayanagi Hiroaki , Ogura Haruo 
Published: March 2009

Abstract1‐Hydroxyphenyl‐2‐pyridone derivatives 8, 10 and 11 were easily prepared by treatment of methyl isocro‐tonate derivatives 6 with base at room temperature in good yields.
Preparation of benzofuroxans and benzofurazans of 2,3,4,5‐tetrahydrobenzo[b] [1,4]dioxocin and related compounds
Authors: Takakis Ioannis M. , Hadjimihalakis Phaedon M. 
Published: March 2009

AbstractThe novel benzofuroxans 1d, 2 and benzofurazans 3,4 have been prepared in good yields. Nitration of 5c furnished the mononitro‐derivatives 6a and 6b in the unusually high relative ratio 6a:6b of 23:77. Direct nitration of 5c or 6a + 6b afforded the unexpected dinitro‐derivative 8b as the major product along with the isomeric 8a, 8c and 8d. Improvement in the yield of 5c (to 86%) is reported.
Synthesis of new imidazole derivatives as potential inhibitors of thromboxane synthetase
Authors: Banfi Aldo , Sala Alberto , Soresinetti P. Angelo , Russo Giovanni 
Published: March 2009

AbstractThe preparation of new imidazole derivatives containing a carboxylic moiety such as succinic, adipic or benzoic into the side chain, is reported starting from the suitable imidazole intermediates.
Nitrogen bridgehead compounds. Part 77. Addition reaction of 9‐methylene‐6,7,8,9‐tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones
Authors: Tóth Gábor , Janke Frank , Hermecz István , Bitter István 
Published: March 2009

AbstractAddition of bromine or thioacetic acid onto 6‐methyl‐9‐methylenetetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones is stereoselective and gives the cis 6‐Me,9‐CH substituted products. Addition is also stereoselective in respect to the C(9) and C(10) centers, and gives as the primary product the erythro diastereomer, which may then undergo epimerization to the threo isomer. Relative configuration and predominant conformation of the products were determined by 1D and 2D nmr methods.
Synthesis of (‐)‐(S)‐3‐sec‐butyl‐ and (+)‐(S)‐5‐sec‐butyl‐2(1H)‐pyridinone
Authors: Chelucci Giorgio , Giacomelli Giampaolo 
Published: March 2009

AbstractOptically active (+)‐(S)‐5‐sec‐butyl‐ and (‐)‐(S)‐3‐sec‐butyl‐2(1H)‐pyridinone are synthesized and the relationship between optical activity and minimum optical purity of the latter is determined.
Mass spectrometric synthesis. V. The gas‐phase ion‐molecule dimerization of some sulfur containing heterocycles
Authors: Audisio Guido , Catellani Marinella , Destri Silvia , Pelli Beatrice , Traldi Pietro 
Published: March 2009

AbstractThe gas‐phase, ion‐molecule reactions occurring in the ion source of a mass spectrometer between differently substituted thiazoles, employed as starting compounds for synthesis of polymers exhibiting semiconducting properties, have been studied in detail. The structural characterization of the dimeric moieties so obtained has been carried out by exact mass measurements, linked scans for metastable analysis and collisional spectroscopy.
Studies on pyrazines. 19 . A novel formation of alkenynylpyrazines in palladium‐catalyzed reaction of 2‐chloropyrazine and its N‐oxide with acetylenes
Authors: Sato Nobuhiro , Hayakawa Akemi , Takeuchi Ryo 
Published: March 2009

AbstractReaction of 3‐chloropyrazine 1‐oxide (1) with 1‐hexyne (2a) in the presence of tetrakis(triphenylphosphine)‐palladium(O) and potassium acetate in DMF afforded 3‐(1‐hexynyl)pyrazine 1‐oxide (3a) and 3‐(2‐butyl‐1‐octen‐3‐ynyl)pyrazine 1‐oxide (4a). The novel formation of 4a was elucidated to result from codimerization of 3a with 2a. The details of reaction are discussed on the basis of findings in palladium(O)‐catalyzed reaction of other chloroheterocycles.
The synthesis and biological activity of 8‐fluoro‐9‐(4‐methyl‐1‐piperazinyl)‐6‐oxo‐6H‐benzo[c]quinolizine‐5‐carboxylic acid
Authors: Ziegler Carl B. , Moran Daniel B. , Fenton Thomas J. , Lin Yang‐I. 
Published: March 2009

AbstractA one‐pot synthesis of ethyl 8,9‐difluoro‐6‐oxo‐6H‐benzo[c]quinolizine‐5‐carboxylate 11 has been developed. The condensation of ethyl 2‐pyridylacetate and 2,4,5‐trifluorobenzoyl chloride followed by intramolecular nucleophilic aromatic substitution gave the desired ring system. This intermediate was converted to the title compound and its in vitro biological activity is reported.
Synthesis of linear polyquaternary salts derived from 4,4′‐Bipyridine
Authors: Summers Lindsay A. , Andriopoulos Nicolaos , Channon Anne‐Louise 
Published: March 2009

Abstract1,1″‐(1,3‐Propanediyl)bis‐4,4′‐bipyridinium dibromide is converted to 1,1″‐(1,3‐propanediyl)bis[1′‐(3‐hydroxypropyl)‐4,4′‐bipyridinium] tetrabromide by reaction with 1,3‐dibromopropane in hot aqueous dimethylformamide. The tetraquaternary salt participates in a dequaternization and coupling reaction on treatment with hot aqueous hydrobromic acid to afford an octaquaternary salt, which is readily converted to decaquaternary and dodecaquaternary derivatives. The 1,4‐butanediyl analogue participates in a similar sequence of reactions.
Novel syntheses of dihydroxanthyletin and dihydroseselin derivatives
Authors: Jetter Michele M. , Heindel Ned D. , Laskin Jeffrey D. 
Published: March 2009

AbstractIn a one‐step alkylation, ring‐closure 7‐hydroxycoumarins are condensed in acid media with allyl and homoallyl halides or alcohols to linear 6,7‐dihydro‐2H,8H‐benzo[1,2–6:5,4‐b']dipyran‐2‐ones. If both carbon‐6 and carbon‐8 are unsubstituted in the original coumarin, cyclization to angular isomers 9,10‐dihydro‐2H,8H‐benzo[1,2–6:3,4‐b']dipyran‐2‐ones competes. These compounds are higher ring homologs of psoralens and angelicins commonly employed in phototherapy of skin disorders.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 2 . Benzo[h][1]benzothieno[2,3‐c]quinoline and benzo[h][1]benzothieno[2,3‐c]quinoline
Authors: Luo Jiann‐Kuan , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of two previously unknown unsubstituted heterocyclic ring systems namely, benzo[h][1]benzothieno[2,3‐c]quinoline (6) and benzo[f][1]benzothieno[2,3‐c]quinoline (12) is reported. These two novel ring systems have been assembled by photocyclization of the appropriate amides.
Synthesis and reaction of methylbenzo[a]quinolizinium salts
Authors: Arai Sadao , Yamazaki Masuo , Hida Mitsuhiko 
Published: March 2009

AbstractAll isomers of (monomethyl)benzo[a]quinolizinium salts including five new monomethyl derivatives were prepared by photocyclization, sulfur extrusion, or cyclodehydration reaction, and their aldol‐type condensation was examined. The 2‐ and 4‐methyl derivatives 3b and 3c reacted with p‐methoxybenzaldehyde in the presence of piperidine to yield trans‐(p‐methoxystyryl)benzo[a]quinolizinium salts 11. The other methyl derivatives did not react with the aldehyde. The methyl group was reactive at the 2‐ and 4‐positions, located para and ortho to the azonia ring nitrogen, respectively; however, it was unreactive at the 6‐position located at another ortho position.
Synthesis of 17β‐hydroxy‐1′‐H‐5α‐androst‐2‐eno[3,2‐b]pyrrole and 17β‐hydroxy‐1′‐H‐5α‐androst‐3‐eno[3,4‐b]pyrrole from O‐(2‐hydroxyethyl)ketoxime precursors
Authors: Ellames George J. , Johnston David , Smith David I. 
Published: March 2009

AbstractPyrrolosteroids such as 17β‐hydroxy‐1′‐H‐5α‐androst‐2‐eno[3,2‐b]pyrrole (1) and the novel 17β‐hydroxy‐1′‐H‐5α‐androst‐3‐eno[3,4‐b]pyrrole (12) can be synthesized from the corresponding O‐(2‐hydroxyethyl)ketoxime precursors. In the case of 1, yields compare favourably with previously reported literature methods.
Pteridines bearing acetylene‐containing sidechains at c‐2:Preparation and attempted cycloaddition reactions
Authors: Haider Norbert , Van Der Plas Henk C. 
Published: March 2009

AbstractThe preparation of a series of pteridine derivatives 1a‐d bearing S‐, O‐, or C‐linked ω‐alkynyl side chains at C‐2 is described. Furthermore, an improved synthesis of 2‐chloropteridine is proposed. Compounds 1a‐d were found not to undergo intramolecular cycloaddition reactions under thermolytic conditions.
Synthesis of 1,2,4‐triazolo[4′,3′:1,6]pyridazino[4,5‐b]quinoline derivatives
Authors: Vomero S. , Anzini M. , Cappelli A. 
Published: March 2009

AbstractThis paper reports the synthesis of 10‐phenyl‐2H‐pyridazino[4,5‐b]quinoline‐1‐thione 10 and its further transformation into the hitherto unknown 12‐phenyl‐1,2,4‐triazolo[4′,3′:1,6]pyridazino[4,5‐b]quinoline 4. 3‐Carbethoxy‐2‐dichloromethyl‐4‐phenylquinoline 8 was reacted with hydrazine to give 9 which in turn was transformed by the Lawesson Reagent into the corresponding thione 10. On treating 10 with anhydrous hydrazine, 11 was obtained and subsequently cyclized in the presence of formic or acetic acids to afford the tetracyclic derivatives 4a and 4b, respectively, in satisfactory yields. When 3‐carbethoxy‐2‐chloromethyl‐4‐phenylquinoline 5 was reacted with hydrazine, compound 7 was the sole isolated product.
An alternate synthesis, x‐ray crystal structure and p388 activity of 1,2‐bis(dibenzophospholyl‐1)ethane
Authors: Sutton Blaine M. , Girard Gerald R. , Eggleston Drake S. , Baures Paul W. , Faucette Leo F. , Johnson Randall K. , Hill David T. 
Published: March 2009

AbstractSynthesis of 1,2‐bis(dibenzophospholyl‐l)ethane (2) in 45% yield was accomplished in a single step via the coupling of 2,2′‐dilithiobiphenyl with 1,2‐bis(dichlorophosphino)ethane. The dilithio reagent was generated in situ by the metalation of 2,2′‐dibromobiphenyl with n‐butyl lithium. The 31P[1H] nmr chemical shift of 2 at δ 11.2 ppm (deuteriochloroform) is slightly upfield from the δ 12.8 ppm observed for 1,2‐bis(diphenylphosphino)ethane, the nonconstrained analog 1, relative to external trimethyl phosphate (δ 31P 2.0 ppm). X‐ray crystallography showed 2 crystallized in space group P21/c with lattice constants a = 5.752(1) Å, b = 12.891(2) Å, c = 13.675(3) Å and β = 100.74(2)° with Z = 2. Compound 2 formed a bis[chlorogold(I)] complex in a fashion similar to the known metal complexing ligand 1. Evaluation of 2 in an ip P388 leukemia mouse model resulted in an increased life span (ILS) of 70% relative to controls, at a maximally tolerated dose (MTD) of 20.2 μmol/kg. By comparison 1 afforded an ILS of 100% at an MTD of 40 μmol/kg.
Methyltriazolocoumarins: New furocoumarin isosters as potential photochemotherapeutic agents
Authors: Rodighiero P. , Chilin A. , Pastorini G. , Guiotto A. , Manzini P. 
Published: March 2009

AbstractA number of new methyltriazolocoumarins with a linear psoralen‐like structure or an angular angelicin‐like structure were synthetized. The syntheses were performed starting from the appropriate methylated 7‐aminocoumarins which were nitrated, reduced and successively diazotized with concomitant cyclization to form the condensed triazolo ring. The new methyltriazolocoumarins show promising spectroscopic properties which are potentially predictive of their photochemical and photobiological behaviour.
An efficient synthesis of the novel triazoloquinazoline adenosine antagonist, CGS 15943
Authors: Gelotte Karl O. , Mason David N. , Meckler Harold , Shieh Wen‐Chung , Starkey Colleen M. 
Published: March 2009

AbstractAn efficient synthesis of the novel triazoloquinazoline adenosine antagonist, CGS 15943, is reported in five steps in approximately 50% overall yield. A key reaction in the synthetic sequence is the double cyclization of an N‐(substituted‐2‐cyanophenyl)carbamate with a carboxylic acid hydrazide to afford a [1,2,4]triazolo‐[1,5‐c]quinazolin‐5(6H)‐one in high yield without either a Dimroth or “translocative” rearrangement occurring. Another key reaction is the condensation of a 2‐(1H‐1,2,4‐triazol‐5‐yl)benzenamine with cyanamide under acidic conditions to prepare a guanidine.
Reactions of triacetylmethane with monosubstituted hydrazines and amidine analogues. Syntheses of 4‐acetyl‐3,5‐dimethylpyrazole amidinohydrazone and 1,3,5‐triazine derivatives
Authors: Takagi Kaname , Bajnati Abdelilah , Hubert‐Habart Michel 
Published: March 2009

AbstractTriacetylmethane (1) reacts with amidinohydrazines in acidic medium to afford 4‐acetyl‐3,5‐dimethylpyrazole amidinohydrazone derivatives 2,4. However, a similar reaction of 1 with thiosemicarbazide or semicarbazide led mainly to 3,5‐dimethylpyrazole (6). The great propensity of 1 to hydrolysis accounts for this last transformation, as well as for the fact that with guanidine it led to 2‐amino‐4,6‐dimethylpyrimidine (10) and with S‐methylisothiourea it provided the unexpected 2‐amino‐4‐methyl‐6‐methylthio‐1,3,5‐triazine (11).
Potassium fluoride‐promoted reaction of (2‐chloro‐2‐nitroethenyl)benzenes with 1,3‐dicarbonyl compounds. A general synthesis of 6,6‐dimethyl‐2‐nitro‐3‐phenyl‐3,5,6,7‐tetrahydro‐4(2H)benzofuranones and some analogs
Authors: Dauzonne Daniel , Demerseman Pierre 
Published: March 2009

AbstractA convenient procedure to prepare in good yields 6,6‐dimethyl‐2‐nitro‐3‐phenyl‐3,5,6,7‐tetrahydro‐4(2H)‐benzofuranones starting from (2‐chloro‐2‐nitroethenyl)benzenes and 5,5‐dimethyl‐1,3‐cyclohexanedione in the presence of potassium fluoride is reported. This method also proved efficient with other 1,3‐dicarbonyl compounds, and has been successfully extended to 1,3‐cyclohexanedione, 2,5‐pentanedione, dibenzoylmethane and ethyl acetoacetate.
Cycloaddition‐elimination reactions of 5‐imino‐1,2,4‐dithiazolidin‐3‐ones with heterocumulenes
Authors: L'Abbé Gerrit , Vandendriessche Anna 
Published: March 2009

Abstract5‐Benzylimino‐1,2,4‐dithiazolidin‐3‐one (2a) reacts with heterocumulenes (isocyanates, isothiocyanates, ketenes) with elimination of carbonyl sulfide, yielding the heterocycles 6–8. The thiadiazolidine 6a, obtained from 2a and phenyl isocyanate, underwent similar reactions but under milder conditions, indicating that phenyl isocyanate is a better leaving group than carbonyl sulfide.
A new and unexpected aminoisoquinoline formed under bischler‐napieralski reaction conditions provides for A new synthesis of 3‐aminoisoquinolines
Authors: Markovich Kimberly M. , Hamada Akihiko , Miller Duane D. 
Published: March 2009

AbstractTreatment of an amide, 1, of a substituted 2‐phenethylamine using Bischler‐Napieralski reaction conditions with acetonitrile as a solvent, gave the desired dihydroisoquinoline 2 as well as an unexpected 3‐aminoisoquinoline product 3. The applicability of this finding as a method of synthesizing 3‐aminoisoquinoline derivatives was examined.
Chemistry of thienopyridines. XXXVIII. Diels‐Alder reactions of thienopyridine sulfones. Part 2
Authors: Klemm L. H. , Sur Sandip K. , Louris John N. , Tran Long K. , Yee Sidney , Hamilton Steven R. 
Published: March 2009

AbstractThieno[3,2‐b]pyridine 1,1‐dioxide (2) undergoes Diels‐Alder condensation with the dienophiles cyclopentadiene, anthracene, and naphthacene in a manner analogous to its isomer thieno[2,3‐b]pyridine 1,1‐dioxide (1). Compound 2 dimerizes in refluxing xylene with the loss of sulfur dioxide plus either the loss or transfer of hydrogen to give a small yield (ca. 2%) of pyrido[2′,3′:4,5]thieno[3,2‐f]quinoline 7,7‐dioxide (7) and its 5,6‐dihydro derivative 12. Formation of 7 and 12 are compared and contrasted with products reported from dimerization of 1 and of benzo[b]thiophene 1,1‐dioxide and its derivatives.
On the methylation of 5‐(4‐alkoxyphenyl)‐15‐(4‐pyridyl)porphyrins
Authors: Roeterdink F. , van der Plas H. C. 
Published: March 2009

AbstractMixed condensation of 3,3′‐diethyl‐4,4′‐dimethyl‐2,2′‐dipyrrolylmethane 1 with 4‐formylpyridine 2 and 4‐alkoxybenzaldehyde 3 in acid medium and subsequent oxidation of the reaction mixture with DDQ gives, among other compounds, title compound 5. An efficient methylation procedure of the pyridyl group in 5‐(4‐alkyoxyphenyl)‐15‐(4‐pyridyl)porphyrins is described. Mixed condensation of 1 with N‐methyl‐4‐formylpyridinium salt 9 and 3 yields among other compounds 5‐(4‐N‐methylpyridiniumiodide)porphyrin 10.
Thiophene systems. 11. The synthesis of novel thieno[4,3,2‐de] tricyclic ring systems
Authors: Russell Ronald K. , Rampulla Richard A. , van Nievelt Caroline E. , Klaubert Dieter H. 
Published: March 2009

AbstractThe synthesis of thieno[4,3,2‐de] tricyclic compounds is described. The N‐1 alkylation of I produced the alkanoic ester precursors. After hydrolysis, the corresponding carboxylic acids were cyclized to the title compounds II. This cyclization step was accomplished with 1:10 phosphorus pentoxide‐methanesulfonic acid. The ketones II were further modified to introduce additional functionality onto this novel tricyclic ring system.
A convenient large scale synthesis of 2,6‐dimethyl‐4‐(trimethylstannyl)pyridine
Authors: Singh Baldev , Lesher George Y. , Pennock Patrick O. 
Published: March 2009

AbstractReaction of phosphorus oxychloride with 2,6‐dimethylpyridine N‐oxide hydrochloride (1) gave a mixture of 2‐(chloromethyl)‐6‐methylpyridine (2) and 4‐chloro‐2,6‐dimethylpyridine (3). Treatment of this mixture with triethylamine converted 2 to the quaternary salt 4 which was separated by water extraction leaving 3 which was subsequently reacted with trimethylstannyl sodium to yield 2,6‐dimethyl‐4‐(trimethylstannyl)pyridine (6).