bluuebunny/crossref_metadata_2025 huggingface dataset:
Disentangling proton connectivity networks in highly overlapped1H‐NMR spectra of polynuclear aromatics using 1D‐HOHAHA
Authors: Shockcor John P. , Crouch Ronald C. , Martin Gary E. , Cherif Abdallah , Luo Jiann‐Kuan , Castle Raymond N.
Published: March 2009

One‐dimensional (1D) variants of two‐dimensional (2D) nmr techniques can frequently provide the required information in a much shorter period of time than the2Dexperiment from which they were derived. Application of the1Dhomonuclear Hartmann‐Hahn (1D‐HOHAHA) experiment to establish proton‐proton connectivity networks in highly overlapped four‐spin systems in the proton nmr spectra of polynuclear aromatics is described. Selective subspectra are contrasted to the data obtained in a COSY experiment on the same molecule, benzo[f][l]benzothieno[2,3‐c]quinoline. Results from the 1D‐HOHAHA technique are especially useful when component resonances from several spin systems are heavily overlapped. Relayed 1D‐HOHAHA provides the means of exploiting small, long range coupling pathways of polynuclear aromatics.
Heterocyclization of 2,4‐disubstituted thiosemicarbazides with haloketones
Authors: Tomita Yasuhiro , Kabashima Shigeru , Okawara Tadashi , Yamasaki Tetsuo , Furukawa Mitsuru
Published: March 2009

2,4‐Disubstituted thiosemicarbazides were allowed to react with α‐bromoacetophenone to give the anticipated 2,3‐dihydro‐6H‐1,3,4‐thiadiazines, whereas with β‐propiophenone and γ‐butyrophenone to afford the unexpected 2,3‐dihydro‐1,3,4‐thiadiazole. The reaction mechanism was also discussed.
Reaction of 1,3,4‐oxadiazolones with free L‐α‐amino acids: A facile synthesis of novel 3,5‐disubstituted hydantoins
Authors: Saegusa Yasuo , Harada Shigeo , Nakamura Shigeo
Published: March 2009

A series of novel 3,5‐disubstituted hydantoins 3a‐1 were easily synthesized in one‐step from the reaction of 2‐phenyl‐1,3,4‐oxadiazolin‐5‐ones 1a‐h with various free L‐α‐amino acids 2a‐e in m‐cresol at 150°. An alternative route leading to the formation of 3‐benzamido‐5‐isopropylhydantoin 3c was also developed to make clear the reaction mechanism.
Chemistry of thienopyridines. XXXVII. Syntheses in the cyclopenta, cyclohexa‐, and cycloheptathieno[2,3‐b]pyridine series. Three analogs of 9‐amino‐1,2,3,4‐tetrahydroacridine
Authors: Klemm L. H. , Wang Jun , Sur Sandip K.
Published: March 2009

4‐Aminocyclopenta‐, 4‐aminocyclohexa‐, and 4‐aminocycloheptathieno[2,3‐b]pyridines were synthesized in very low overall yield by four‐step procedures starting from bis(2‐thienylammonium) hexachlorostannate(IV) and 2‐hydroxymethylenecyclopentanone, 2‐methoxymethylenecyclohexanone, and 2‐hydroxymethylenecycloheptanone, respectively.
Stereoselective ring closure of 6‐[[(methylamino)carbonyl]oxy]‐2H‐pyran‐3(6H)‐ones. Formation of the 5H‐pyrano[3,2‐d]oxazole‐2,6‐dione ring system
Authors: Georgiadis Minas P. , Couladouros Elias A.
Published: March 2009

The stereospecific formation of the 5H‐pyrano[3,2‐d]oxazole‐2,6‐dione ring system from 2,2‐disubstituted‐6‐[[(methylamino)carbonyl]oxy]‐2H‐pyran‐3(6H)‐one via an enolization at C‐5 is presented. The outcome of the same reaction in the case of 2‐monosubstituted 2H‐pyran‐3(6H)‐ones is also discussed.
The synthesis of ring‐expanded analogues of xanthine containing the imidazo[4,5‐e][1,4]diazepine ring system
Authors: Hosmane Ramachandra S. , Bhan Anila
Published: March 2009

The synthesis of 4,5,7,8‐tetrahydro‐6H‐imidazo[4,5‐e][1,4]diazepine‐5,8‐dione and its several 1‐ and 3‐alkyl (aralkyl) derivatives 2 has been reported. Mechanistic explorations of the final synthetic step as well as structural confirmation of a final product 2d by single‐crystal X‐ray diffraction analyses have also been presented.
Some fatty acids having an O‐heterocycle in their terminal positions. I. ω‐(3‐Chromonyl)alkanoic acids
Authors: Yamaguchi Seiji , Mutoh Masao , Shimakura Masaaki , Tsuzuki Kunihiro , Kawase Yoshiyuki
Published: March 2009

Some ω‐(3‐chromonyl)alkanoic acid derivatives, 1a and 2a, n = 4, 5; 3a, 4a and 5a, n = 2‐6, were synthesized by cyclization of corresponding methyl ω‐(2‐hydroxybenzoyl)alkanoates 7b or ethyl ω‐(2,4‐dihydroxybenzoyl)alkanoates 8b with N,N‐dimethylformamide‐dimethyl acetal or acetic anhydride‐DBU followed by hydrolysis.
Preparation of 9‐aryl (or heteroaryl)methylidene‐10‐(methoxyimino)‐phenanthrenes and their thermal electrocyclisation to fused quinolines
Authors: Nicolaides Demetrios N. , Litinas Konstantinos E. , Papageorgiou Georgios K. , Stephanidou‐Stephanatou Julia
Published: March 2009

o‐Quinone methanide N‐methoxyimines 6a‐c, 7a‐c, 11a‐b and 12a, easily prepared from the reaction of 10‐(methoxyimino)phenanthrene‐9‐one (3) with phosphonium salts 5a‐c, 10a‐b in the presence of lithium hydroxide, are thermally converted into dibenzo[f,h]quinolino[2,3‐x]fused compounds 9a‐c and 13a‐b, in high yield.
Synthesis and reaction of 2‐imino‐1,3‐thiazetidines and 2‐imino‐1,3‐dithietanes
Authors: Okajima Nobuyuki , Okada Yoshiyuki
Published: March 2009

2‐Imino‐1,3‐thiazetidines and 2‐imino‐1,3‐dithietanes were synthesized and their reactivities were studied. The former readily underwent ring‐opening reaction with amines to yield guanidine derivatives. The reaction products were applied to the synthesis of heterocycles such as triazoles and triazines. The latter was converted to isothiocyanate by the reaction of m‐chloroperbenzoic acid.
Ladder oligophenothiazines by direct thionation of N‐Arylanilino Derivatives
Authors: Andreani Franco , Bizzarri Paolo Costa , Casa Carlo Delia , Fiorini Maurizio , Salatelli Elisabetta
Published: March 2009

Ladder oligophenothiazines were synthesized by direct catalyzed insertion of elemental sulfur in anilino‐substituted phenothiazines and para‐oligoanilines. The starting 3‐ and 3,7‐anilino derivatives of phenothiazine were prepared with improved selectivities and yields by new syntheses. The oxidability of the oligomers is discussed.
A novel method for the synthesis of 4‐isoquinolinols
Authors: Uno Hidemitsu , Okada Shin‐Ichiro , Suzuki Hitomi
Published: March 2009

1‐Substituted 1,2‐dihydroisoquinolines, derived from isoquinoline and organolithium reagents, readily undergo autoxidation to lead to 4‐isoquinolinols in moderate yields.
The syntheses of 4b,5a‐dihydrodibenz[3,4:5,6]anthra[1,2‐b]oxirene and 4b,5a‐dihydro‐5H‐dibenz[3,4:5,6]anthra[1,2‐b]azirine
Authors: Abu‐Shqara Elias , Blum Jochanan
Published: March 2009

The syntheses of the K‐oxide and K‐imine derivatives of dibenz[a,j]anthracene (1) are described. The parent hydrocarbon 1 that was obtained as a side product in the Elbs pyrolysis of (2‐methyl‐1‐naphthyl)‐1′‐naphthylmethanone (10) was oxidized to 3‐(2‐formylphenyl)‐3‐phenanthrenecarboxaldehyde (3). Treatment of the dialdehyde with tris(dimethylamino)phosphine gave 4b,5a‐dihydrodibenz[3,4:5,6]anthra[1,2‐b]oxirene (4). Reaction of the oxirane with sodium azide followed by triethyl phosphite cyclization of the mixture of trans azido‐alcohols so formed, yielded mainly 4b,5a‐dihydrodibenz[3,4:5,6]anthra[1,2‐b]azirine (5).
Syntheses and reactions of [1,3,4]thiadiazolo[3,2‐a]pyrimidinone derivatives
Authors: Tsuji Tadakazu
Published: March 2009

5‐Imino‐6H‐7‐one, 7‐amino‐5‐one and 5‐isocyano‐7‐one derivatives of [1,3,4]thiadiazolo‐ and ‐[1,3]thiazolo‐[3,2‐a]pyrimidines were synthesized. 5‐Isocyano‐7‐one derivatives were obtained by the reaction of the corresponding 5‐imino‐6H‐7‐ones with the Vilsmeier reagent in one step.
Synthesis of pyrimidine derivatives using N‐bis(methylthio)methylenecyanamide
Authors: Tominaga Yoshinori , Ohno Syuichirou , Kohra Shinya , Fujito Hiroshi , Mazurae Hisako
Published: March 2009

N‐Bis(methylthio)methylenecyanamide (1) was allowed to react with active methylene compounds (methyl cyanoacetate, dimethyl malonate, ethyl acetoacetate, ethyl phenylacetate) in the presence of potassium carbonate or potassium hydroxide in dimethyl sulfoxide followed by the treatment using appropriate a base or an acid to give the corresponding 6‐methylthiouracil derivatives in 15–80% yields.

These uracil derivatives are found to be useful intermediates for the synthesis of 6‐aminouracils and fused pyrimidine derivatives.
Synthesis and antibacterial activities of novel dihydrooxazine and dihydrothiazine ring‐fused tricyclic quinolonecarboxylic acids: 9‐Fluoro‐3‐methylene‐10‐(4‐methylpiperazin‐1‐yl)‐7‐oxo‐2,3‐dihydro‐7h‐pyrido[1,2,3‐de][1,4]benzoxazine‐6‐carboxylic acid and its 1‐thia congener
Authors: Okada Tetsuo , Tsuji Teruji , Tsushima Tadahiko , Yoshida Tadashi , Matsuura Shinzo
Published: March 2009

A new synthetic method was developed to obtain two novel tricyclic quinolonecarboxylic acids, 9‐fluoro‐3‐methylene‐10‐(4‐methylpiperazin‐1‐yl)‐7‐oxo‐2,3‐dihydro‐7H‐pyrido[1,2,3‐de][1,4]benzoxazine‐6‐carboxylic acid (2) and its 1‐thia congener 3. The method involves the key intermediate of an oxetane derivative and its cleavage with acids. Evaluation of the antibacterial activities showed that 2 and 3 are excellent against both Gram‐positive and Gram‐negative organisms in vitro, being comparable to or only slightly less effective than Ofloxacin. In experimental systemic infections in mice, compound 2 showed distinctly higher activity than Ofloxacin, especially against infection caused by Escherichia coli.
Pyrazoles. 6. Synthesis of novel heteroaryl 4‐pyrazolyl ketones
Authors: Hahn Marianne , Heinisch Gottfried , Holzer Wolfgang , Schwarz Helga
Published: March 2009

The preparation of a variety of novel heteroaromatic analogues of benzophenone 2–11 characterized by a 4‐pyrazolyl moiety and a thienyl‐, azinyl‐ or diazinyl‐system starting from 1,4‐dilithiopyrazole is reported.
Alkylation of cycloalkano[B]indoles via indolylmagnesium salts: Synthesis of 3h‐indoles and oxidative rearrangement to spiro[cycloalkane‐1,2′‐indolin]‐3′‐ones
Authors: Rodriguez JosÈ‐Gonzalo , Andrès Angel San
Published: March 2009

Alkylation of cycloalkano[b]indolylmagnesium iodide with alkyl halides has been analyzed to prepare cycloalkano‐3H‐indoles, methyl and N,N‐dimethylpropyl derivatives. Spiro[cycloalkane‐1,2′‐indolin‐3′‐one] derivatives appear as secondary products in this reaction. Selectivity and optimization of the reaction has been determined and a mechanism for the formation of the spiro derivative is proposed.
A convenient synthesis of ethyl 2‐(4‐nitrophenyl)‐3,4‐disubstituted and c‐fused thiophene‐5‐carboxylates
Authors: Rangnekar D. W. , Mavlankar S. V.
Published: March 2009

A convenient one step synthesis of the hitherto unknown ethyl 2‐(4‐nitrophenyl)‐3,4‐disubstituted and c‐fused thiophene‐5‐carboxylates was achieved by the condensation of ethyl 4‐nitrobenzylthioacetate with a variety of 1,2‐dicarbonyl compounds using sodium ethoxide in refluxing ethanol.
Synthesis of 3‐disubstituted 3H‐4,1,2‐benzothiadiazines and 3‐disubstituted 3H‐4,1,2‐benzothiadiazine 4,4‐dioxides
Authors: Balbi A. , Mazzei M. , Sottofattori E.
Published: March 2009

3H‐4,1,2‐Benzothiadiazines 8 and 9 have been prepared by cyclization of the key intermediates 6 and 7. The diazotisation of 2‐aminophenylthio and 2‐aminophenylsulfone derivatives could represent a new convenient synthetic way to obtain 4,1,2‐benzothiadiazines.
Synthesis of pyrazole derivatives as potential bioisosteres of thromboxane‐synthetase inhibitors
Authors: Barreiro Eliezer J. , Freitas Antonio C. C.
Published: March 2009

A series of ω‐carboalkenyl pyrazole derivatives have been synthesized as potential thromboxane‐synthetase inhibitors considering the close bioisosteric relationship between the pyrazole ring and other heteroaromatic carboalkenyl compounds exhibiting inhibitory activity. (E)‐7‐(1‐Phenylpyrazol‐4‐yl)hept‐2‐enoic acid (4b) were prepared in 28% overall yield from its minor bis‐homologue, (E)‐5‐(1‐phenylpyrazol‐4‐yl)pent‐2‐enoic acid (4a), obtained from 4‐formyl‐1‐phenylpyrazole (6) in 17% overall yield. Compounds 4a, 4b, 7, 8 and 13 were screened for their ability to inhibit the in vitro rabbit blood platelet aggregation induced by collagen using the Born test. Among the active compounds 4a exhibited an important inhibition at 1 μM concentration.
Intramolecular sulphonamidomethylation. Part II. Fused heterocycles from 2‐phenylethanesulphonamides
Authors: Zinczuk Juan , Sorokin Isidoro H. , Orazi Orfeo O. , Corral Renée A.
Published: March 2009

1,2,4,5‐Tetrahydro‐3,2‐benzothiazepine 3,3‐dioxides 2, with a variety of substituents on the nitrogen atom, can be easily obtained by the title reaction. The isomeric compounds 4–6 are also formed from sulphonamides bearing an N‐aralkyl group with a chain of two or more carbon atoms. Activation of the ring closure‐position or deactivation of the aromatic ring in the substituent can direct the reaction to give compounds 2. Cyclization results are influenced by the size of the new heterocycle ring and by the predominant formation of derivatives with the SO2 group outside the ring.
Synthesis of 7‐ and 5,7‐substituted‐6‐fluoro‐2‐methyl‐1,2,3,4‐tetrahydroquinolines: Convenient precursors of quinolone antibacterial agents
Authors: Bouyssou Pascal , Le Goff Corinne , Chenault Jacques
Published: March 2009

An original procedure to obtain substitution at the 7 or 5, 7 positions on 6‐halogenated tetrahydroquinaldines is described. The title products are a new class of precursors of quinolone antibacterial agents.
Facile synthesis of 2‐[1‐(alkylthio)alkyl]pyridines and phenyl‐substituted derivatives
Authors: Kiselyov Alexander S. , Strekowski Lucjan , Semenov Victor V.
Published: March 2009

The title compounds 5 are produced in the reaction of N‐fluoropyridinium tetrafluoroborate (1) with sulfides 2. The proposed mechanism involves single‐electron transfer from 2 to 1 followed by transformations of the resultant radical intermediates.
On triazoles. XXIX. The reaction of triazolyl thiohydrazides with isocyanates and isothiocyanates
Authors: Reiter József , Barkóczy József
Published: March 2009

Different N‐methylsubstituted, N'‐methylsubstituted and N,N'‐unsubstituted triazol‐1‐ylcarbothiohydrazides were reacted with isocyanates and isothiocyanates to yield the corresponding carbamoyl and thiocarbamoyl derivatives 4. The thiocarbamoyl derivatives could be cyclised by heating in dimethylformamide or 10% sodium hydroxide solution, reacting them with dicyclohexylcarbodiimide or thier alkylation to the corresponding 1,3,4‐thiadiazoles 12 and 16, and derivatives 5 formed by splitting the triazole moiety. Cleaved derivatives 9 and 11 were also formed in the reaction of thiocarbamoyl derivatives 4 with carbon disulfide in the absence or presence of methyl iodide, respectively. Spectroscopic evidence is given for the structure of products obtained.
A convenient synthesis of 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐1,4‐benzoxazine‐2‐carboxylic acids and 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐pyrido[3,2‐b]‐1, 4‐oxazine‐2‐carboxylic acid
Authors: Suhadolc Elizabeta , Urleb UroŠ , Žbontar Urša , Kikelj Danijel
Published: March 2009

A convenient one pot synthesis of ethyl 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐1,4‐benzoxazine‐2‐carboxylates and 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐pyrido[3,2‐b]‐1,4‐oxazine‐2‐carboxylates and their conversion into the respective carboxylic acids are described.
Synthesis of imidazo[4,5‐c]quinolin‐4(5H)‐one via radical cyclization
Authors: Suzuki Fumio , Kuroda Takeshi
Published: March 2009

The tributyltin radical‐induced cyclization of N‐(2‐bromophenyl)‐Nbutyl‐1H‐1‐methylimidazole‐4‐carbox‐amide 3 gave 5‐butyl‐3‐methyl‐3H‐imidazo[4,5‐c]quinolin‐4(5H)‐one 5 via [1,2]‐acyl rearrangement.
The synthesis of substituted 1,5‐benzodiazepines
Authors: Cohen Victor I. , Jin Biyun , Reba Richard C.
Published: March 2009

The synthesis of some substituted 1,5‐benzodiazepines are described. The route is based on the reaction between 1,4‐phenylenediamine and its derivative with crotonic acid or methacrilic acid.
Reissert compound studies LXVI. Regioselective synthesis of pyridine reissert analogs
Authors: Duarte F. F. , Popp F. D. , Holder A. J.
Published: March 2009

The reaction of ethyl chloroformate and pyridine with diethylaluminum cyanide as the cyanide source gave the Reissert analog, 1‐ethoxycarbonyl‐4‐cyano‐1,4‐dihydropyridine and not the expected 1,2‐dihydro regio isomer. Under the same conditions, 3‐bromopyridine also directly gave the corresponding 1,4‐dihydro Reissert analog. Reinvestigation of trimethylsilylcyanide, as the cyanide source, resulted in the observation that both regio isomers are formed and the ratio of these isomers are affected by both solvent polarity and by copper(I) iodide.
Acetylene chemistry. Part 28. New C‐2 substituted furo[2,3‐b]quinolines via Pd‐catalyzed reaction
Authors: Reisch Johannes , Nordhaus Petra , Pflug Thomas
Published: March 2009

Four new C‐2 substituted furo[2,3‐b]quinolines have been synthesized via Pd‐catalyzed reaction. The present study was to provide furo[2,3‐b]quinolines for biological studies on the influence of the side chain length and its polarity of the biological activity particularly against phytopathogenic bacteria and fungi.
Synthesis and characterization of the new 22‐π aromatic furan‐containing macrocycle, “ozaphyrin”
Authors: Miller Douglas C. , Johnson Martin R. , Becker John J. , Ibers James A.
Published: March 2009

The new 22‐π, aromatic “pentaplanar” macrocycle, ozaphyrin (6), has been synthesized by a McMurry coupling of 5,5′‐diformyl‐4,4′‐dipropyl‐2,2′‐bipyrrole (1) with 2,5‐bis(5‐formyl‐4‐propyl‐2‐pyrrolyl)furan (5). This synthetic pathway to ozaphyrin and its characterization by 1H nmr spectroscopy, uv‐visible spectroscopy, cyclic voltammetry, and X‐ray crystallography are described. The structure consists of layers of planar, staggered macrocycles stacked perpendicular to the α‐axis. Ozaphyrin crystallizes with four formula units in the monoclinic space group C52h‐P21/n in a cell of dimensions a = 10.481(7) Å, b = 17.353(17) Å, c = 18.726(12) Å, and β = 102.84(5)° (108 K). The structure has been refined on F2 (5171 unique reflections, 411 variables) to Rw(Fo2) = 0.165. The conventional agreement index R(F) is 0.074 for the 3289 reflections have Fo2>2o(Fo2).
Synthesis and photophysical properties of fluorescent 2,5‐dibenzoxazolylphenols and related compounds with excited state proton‐transfer
Authors: Kauffman Joel M. , Bajwa Gurdip S.
Published: March 2009

A series of new 2,5‐dibenzoxazolylphenols and related compounds was prepared by condensation of hydroxy‐ and methanesulfonamidoterephthalic acids with 2‐aminophenols. These displayed excited state intramolecular proton‐transfer fluorescence at room temperature and above with quantum yields as high as 0.48 and emission peaks of 492‐517 nm. The methanesulfonamido group was found about as effective a proton donor as the phenolic hydroxyl group. Incorporation of substituents onto the benzoxazole moieties increased solubility of the fluors in hydrocarbon solvents in some cases, but reduced quantum yields. These fluors are of interest as wavelength shifters in a scintillating detecting medium for ionizing radiation.
Assignment of the Phosphorus, Proton and Carbon‐NMR Spectra of [(Tetrahydro‐2‐hydroxy‐5,5‐dimethyl‐4H‐1,4,2‐oxazaphosphorin‐4‐yl)methyl] phosphonic acid P‐Oxide
Authors: Dhawan Balram , Redmore Derek , Boyd Walter A.
Published: March 2009

The 1H and 13C nmr signals of the methylene groups directly linked to the phosphorus atoms, namely P(2)‐C(3)H2 and P(8)‐C(7)H2 in 1a were assigned with the help of hetronuclear decoupling experiments and HETCOR spectrum.
A new route to pyridine derivatives by the reaction of tris(isopropylthio)cyclopropenylium perchlorate with α‐lithiated isocyanides
Authors: Kojima Hideo , Yamamoto Kazuhiko , Kinoshita Yasuo , Inoue Hiroo
Published: March 2009

The reaction of tris(isopropylthio)cyclopropenylium perchlorate (1) with α‐lithiated tosylmethyl, benzyl and benzoylmethyl isocyanides 2a‐c in dry tetrahydrofuran gave the pyridine derivatives 3a‐c respectively.
Synthesis of 1‐aryl‐5‐chloro‐3‐(phenylsulfonyl)pyrazol‐4‐ols from 1,1‐dichloro‐3‐phenylsulfonyl‐2‐propanone
Authors: Takahashi Masahiko , Zheng Min , Oshida Takeshi , Narahara Kiyosi
Published: March 2009

1,1‐Dichloro‐3‐phenylsulfonyl‐2‐propanone was treated with arenediazonium chlorides to give 1‐arylhydrazono‐3,3‐dichloro‐1‐phenylsulfonyl‐2‐propanones, which were cyclized to 1‐aryl‐5‐chloro‐3‐(phenylsulfonyl)pyrazol‐4‐ols on treatmemt with base.
Coumarin as dipolarophile towards 3,5‐dichloro‐2,4,6‐trimethylbenzonitrile oxide
Authors: Baldoli Clara , Gioffreda Fabio , Zecchi Gaetano
Published: March 2009

The reaction of coumarin with the title nitrile oxide gives a single regioisomer in high yield. This result is compared with the dipolarophilic behavior of cinnamic acid esters.
New general synthesis of tetrahydro‐1,2,4,5‐tetrazin‐3(2H)‐one derivatives and stable 3,4‐dihydro‐3‐oxo‐1,2,4,5‐tetrazin‐1(2H)‐yl radical derivatives
Authors: Milcent René , Barbier GÉO , Capelle Sylvie , Catteau Jean‐Pierre
Published: March 2009

Reactions of 2‐chloroformylhydrazones of aromatic aldehydes or ketones 2 with various hydrazines were converted to monocarbonohydrazone derivatives 3 or 5 and/or tetrahydro‐1,2,4,5‐tetrazin‐3(2H)‐one derivatives 6, 7. By oxidation with lead dioxide, compounds 6 were transformed into stable 3,4‐dihydro‐3‐oxo‐1,2,4,5‐tetrazin‐1(2H)‐yl radical derivatives 8.
Unusual ring transformations: Reaction of phenyl 7‐fluoro‐4‐chromone‐3‐sulfonate with methyl 3‐oxo‐pentanoate in the presence of ammonium acetate
Authors: Löwe Werner , Schott Susan
Published: March 2009

The novel benzoxathiinopyridines 4 and 5, the hitherto unknown dibenzopyrone 6 and the heterocyclic enaminone 7 have been synthesized by ring transformations of phenyl 7‐fluoro‐4‐chromone‐3‐sulfonate (1) with methyl 3‐oxopentanoate (2) in the presence of ammonium acetate (3). The structures of 4–7 were determinated by spectroscopic methods and the reaction pathways of formation for these compounds are discussed.
3‐Amino‐2‐quinoxalinecarbonitrile. New fused quinoxalines with potential cytotoxic activity
Authors: Monge A. , Palop J. A. , Piñol A. , Martínez‐Crespo F. J. , Narro S. , González M. , Sáinz Y. , De Ceráin A. López , Hamilton E. , Barker A. J.
Published: March 2009

Starting with 3‐amino‐2‐quinoxalinecarbonitrile 1,4‐dioxide 1, a new series of quinoxaline derivatives was prepared through chemical modifications of the 2‐cyano and 3‐amino groups. Nitration of 3‐amino‐2‐quin‐oxalinecarbonitrile 3 afforded the 7‐nitro derivative 6. Diazotation of 3 gave the 3‐chloro compound 9. 2,3‐Quinoxalinedicarbonitrile 14 was obtained from 9. Pyridazino[4,5‐b]quinoxalines 15 and 16 were prepared by condensing 14 with hydrazine hydrate. A triazolo[4,5‐b]quinoxaline 18, a isothiazolo[4,5‐b]quinoxaline 20 and two pyrazolo[3,4‐b]quinoxalines 21 and 22 were identified. Compounds were tested as cytotoxic agents both in oxic and in hypoxic cells.
Synthesis of 2,3,5‐trisubstituted furans by the acid‐catalyzed decomposition of 1,2‐dioxan‐3‐ols
Authors: Qian Chang‐Yi , Hirose Jun‐Ichi , Nishino Hiroshi , Kurosawa Kazu
Published: March 2009

Thirteen new 2,3,5‐trisubstituted furans were prepared by the acid‐catalyzed decomposition of 6,6‐di‐substituted 1,2‐dioxan‐3‐ols in 57‐93% yields. The reaction could be accounted for as the consequence of an oxygen‐oxygen bond cleavage by acid and the migration of a phenyl group at the C‐6 position followed by cyclization and elimination of a phenol. The migratory aptitude was in the order of 4‐MeOC6H4‐ > 4‐MeC6H4‐ > Ph‐ = 4‐FC6H4‐ > 4‐ClC6H4‐ = 4‐BrC6H4‐ that was found from the competitive phenyl migration in the reaction of 1,2‐dioxan‐3‐ols bearing two different substituents at the C‐6 position.
New regional isomers of 1‐methyl‐5‐(trifluoromethyl)pyrazoles
Authors: Chupp John P.
Published: March 2009

Utilizing the recently reported compound, 1‐methyl‐5‐(trifluoromethyl)‐2,3,4,5‐tetrahydropyrazol‐3‐one, 4, a series of regional isomers of 1‐methyl‐5‐(trifluoromethyl)‐3‐chloropyrazole, newly substituted in the 4‐position were prepared by original syntheses. Chief among them was the new regional 4‐hydroxy isomer, 3a, a linkage reagent valuable for preparing new SAR candidates in the bio‐active pyrazole phenyl ether series.
An improved procedure for the preparation of 2‐amino‐8‐alkylpyrido‐[2,3‐d]pyrimidin‐4(3H)‐ones (8‐alkyl‐N5‐deazapterins)
Authors: Ivery Michael T. G. , Gready Jill E.
Published: March 2009

We report an improved procedure for the preparation of 8‐alkyl‐N5‐deazapterins which allows clean preparation of all ring‐methyl substituted compounds, including 5‐ and 7‐methyl substituted compounds. The procedure was also successfully applied to the preparation of N5‐deazapterins with improved yield over previous reports. The uv/visible and pKa data confirm the predicted increased basicity of 8‐alkyl‐N5‐deazapterins compared with the N5‐deazapterin parents, and indicate that N5‐deazapterins protonate on N8 and 8‐alkyl‐N5‐deazapterins protonate on N3.
Reductive cyclization of 1‐(2‐nitroaryl)isoquinoline derivatives
Authors: Stanley Alan L. , Stanforth Stephen P.
Published: March 2009

Isoquinoline derivatives 3b and 3c were prepared and their triethyl phosphite mediated reductive cyclization reactions investigated. Only the indazolo[3,2‐a]isoquinolines 4b and 4c were formed.
Development of a stereoselective and chemoselective approach to trans‐2,3‐disubstituted‐4‐chromanones
Authors: Chambers R. J. , Marfat A.
Published: March 2009

A direct synthesis of chromanones 10 and 11 was achieved in five steps from acetophenone 1 in an overall yield of 37% and 53% respectively. The requisite 2,3‐trans stereochemistry in chromanone 10 and 11 was set by a chemoselective and stereoselective conjugate reduction of chromones 8 and 9.
Synthesis of 2,6‐di‐tert‐butylphenols linked to 1,3,4‐oxadiazoles and 1,3,4‐thiadiazoles
Authors: Kramer James B. , Boschelli Diane H. , Connor David T.
Published: March 2009

The preparation of a series of analogs of 2,6‐di‐tert‐butylphenol linked to a 1,3,4‐oxadiazole or 1,3,4‐thiadiazole via an ethylene or methyleneoxy spacer is discussed.
Synthesis and preliminary cytotoxic activity of dimethoxy‐acridines and dimethoxynitroacridines
Authors: Monge A. , Martínez‐Crespo F. J. , Santamaría L. , Narro S. , De Ceráin A. López , Hamilton E. , Barker A. J.
Published: March 2009

The preparation of a series of dimethoxy and dimethoxynitroacridines and their activity in oxic and hypoxic cells is reported. Anthranilic acids 1,4,14 were prepared according to the Ullmann condensation. 9‐chloroacridines were obtained from anthranilic acids by refluxing in phosphorus oxychloride. The synthesis of two new acridine dimers 9,10 is described. Nitration of 9‐chloro‐2,4‐dimethoxyacridine 15 gave 3‐nitro isomer 19. By phenol‐mediated coupling reaction from all the 9‐chloroacridines, the respective 9‐(alkylamino)acridines were obtained. By nitration of 17 a new 2,4‐dimethoxy‐3,7‐dinitroacridine 21 was prepared
Synthesis of 6‐(pyrrol‐1‐yl)purine and of some of its 9‐glycosides
Authors: Haidoune M'Barek , Mornet René
Published: March 2009

Adenine reacts slowly with 2,5‐dimethoxytetrahydrofuran (3) in a dilute acetic acid solution in methanol‐water, to give 6‐(pyrrol‐1‐yl)purine (4). Under more acidic conditions, 4 is partly transformed to 6‐(indol‐1‐yl)purine (5) and other unidentified products. The reaction may be used for the preparation of 9‐glycosides of 4 from the corresponding adenine derivatives provided their 9‐glycosyl linkage is somewhat resistant to acid hydrolysis.
Stereochemical effects in the nitrosation of some α,β‐unsaturated ketoximes. Formation of 1‐hydroxypyrazole 2‐oxides and 4‐oximino‐4,5‐dihydroisoxazoles
Authors: Hansen John F. , Easter John A.
Published: March 2009

Several α,β‐unsaturated ketoximes R1CH=CHC(=NOH)R2 were nitrosated using butyl nitrite in aqueous ethanol in the presence of copper(II) sulfate and pyridine. The product distribution varied depending on whether the oxime hydroxyl group was syn or anti with respect to the carboncarbon double bond. The anti‐oximes gave the copper complexes of 1‐hydroxypyrazole 2‐oxides in high yields. The isomeric syn‐oximes gave lower yields of the pyrazole complexes along with 4‐oximino‐4,5‐dihydroisoxazole derivatives. For the syn‐oximes where R1 is phenyl and R2 is either methyl or ethyl, conversion of the oximes to the parent ketones was also observed. The results may be explained by processes involving N‐nitrosonitrone intermediates.
1,3‐Dipolar cycloaddition reactions of nitrones with vinylacetic olefins in the racemic series and synthesis of δ‐lactams via isoxazolidines
Authors: Chanet‐Ray Josette , Charmier‐Januario Marie Odile , Vessière Roger , Zuccarelli Marie
Published: March 2009

A study of the cycloaddition behavior of a series of esters and nitriles α‐chloro‐ and α‐hydroxyvinyl‐acetic dipolarophiles with C‐aryl‐N‐alkylnitrones has been carried out. Regiospecific cycloadditions are observed; the reactions lead to a mixture of 5‐substituted isoxazolidines either erythro or threo, wherever the nitrone is involved. We report the synthesis of some δ‐lactams in which isoxazolidines are used as latent synthons.
The reactions of heterocyclic isothiocyanates bearing an ortho ester group with N‐nucleophiles. The scope and some limitations of the reaction
Authors: Urleb Uroš
Published: March 2009

Heterocyclic isothiocyanates bearing an o‐ester group were converted into thiourea derivatives 2, 5, 6, 7, and 9 using sterically large primary amines or aminoacids, and to the fused ring systems, e.g. 12H‐pyrido[3′,2′:4,5]pyrimido[2,1‐b]benzothiazol‐12‐one (3), and 6,7‐dihydro‐9H‐thiazolo[3,2‐a]thieno[3,2‐d]‐pyrimidin‐9‐one (13), respectively, using bifunctional reagents such as 2‐aminothiophenol or cysteamine.
Unexpected behaviour of the oxidizing agent sodium m‐nitrobenzenesulfonate: Synthesis of a new class of 5‐hydroxy benzopyrano‐[4,3‐c]pyridazin‐3(2H)‐ones
Authors: Cignarella Giorgio , Barlocco Daniela
Published: March 2009

Sodium m‐nitrobenzene sulfonate, widely used in dehydrogenation of 4,5‐dihydro‐3(2H)‐pyridazinones to their corresponding aromatic derivatives, behaves in an unexpected way when 4,4a‐dihydro‐5H[1]benzopyrano[4,3‐c]pyridazin‐3(2H)‐ones are employed as substrate. The synthesis of a new class of 5‐hydroxy[1]benzopyrano[4,3‐c]pyridazin‐3(2H)‐ones is described.
An improved one‐step method to prepare some diaza‐crown ethers and the cation complexation properties of 4,10‐diaza‐18‐crown‐6 with two transition metal ions
Authors: Krakowiak Krzysztof E. , Maas Garren E. , Bradshaw Jerald S. , Hathaway Jon K. , Izatt Reed M.
Published: March 2009

4,10‐Diaza‐15‐crown‐5, 4,10‐diaza‐18‐crown‐6, 4,13‐diaza‐21‐crown‐7, and 4,16‐diaza‐24‐crown‐8 were prepared by an improved method from the appropriate oligothylene glycol diiodides and diamines. The thermodynamic values of log K, ΔH and ΔS for the interaction of 4,10‐diaza‐18‐crown‐6 with Pb2+ and Ag+ were determined by a calorimetric titration method and compared with thermodynamic values for interactions of 4,13‐diaza‐18‐crown‐6 with the same cations. The thermodynamic values were found to be different for the two diaza‐crown ligands. 4,10‐Diaza‐18‐crown‐6 and its 4,13‐diaza‐crown analog formed precipitates when treated with Co2+, Cd2+, Cu2+, and Ni2+ so that no thermodynamic data are reported for these interactions.
Synthesis and 13C NMR study of some N‐substituted 4‐iodo‐ and 3,4‐diiodopyrazoles
Authors: Holzer Wolfgang , Pöcher Ingrid
Published: March 2009

The synthesis of some novel N‐1 substituted 4‐iodo‐ and 3,4‐diiodopyrazoles starting from the corresponding NH‐pyrazoles is described. On basis of their 13C nmr data and those of already known related congeners the influence of iodo‐ as well as N‐1 substituents on pyrazole 13C chemical shifts and 13C,1H spin coupling constants is investigated.
Stereoselective reduction of new fused azoninones with a bridgehead nitrogen
Authors: Berkes Dusan , Bar Nathalie , Decroix Bernard
Published: March 2009

The synthesis of methanothienoazoninones 5a,b is described starting from 2(3)‐halogenomethylthio‐phenes. Their reduction with sodium borohydride led to the corresponding aminoalcohols 6a,b with a complete stereoselectivity.
Heterocyclization of propenethioamides: A direct synthesis of 1,4‐thiazepine ring systems
Authors: Cocco Maria Teresa , Congiu Cenzo , Onnis Valentina
Published: March 2009

The heterocyclization of 3‐aminopropenethioamides 1 and 2 with 2‐bromoacetophenone is reported. The p‐toluenesulphonic acid catalyzed reaction gives a direct route to 1,4‐thiazepines 3 and 5, while in the presence of triethylamine thiophene 4 and 1,4‐thiazepin‐5‐one 6 are obtained.
Synthesis of 3‐nitrophthalonitrile and tetra‐α‐substituted phthalocyanines
Authors: George Robert D. , Snow Arthur W.
Published: March 2009

An efficient synthesis of phthalocyanines prepared from ortho‐substituted phthalonitriles is described. The precursor to these phthalocyanines, 3‐nitrophthalonitrile, is a key reagent for syntheses of phthalonitriles substituted at the 3‐position by means of nucleophilic aromatic substitutions. An example of this type of phthalocyanine, prepared from 3‐(4‐cumylphenoxy)phthalonitrile, is compared with the phthalocyanine derived from 4‐(4‐cumylphenoxy)phthalonitrile. Substitution of the phthalocyanine at this more sterically crowded site causes a 20 nm bathochromic shift of the Q‐band (π‐π* transition).
Synthesis of triflouromethylated pyridinecarbonitriles
Authors: Cocco Maria Teresa , Congiu Cenzo , Onnis Valentina
Published: March 2009

Enaminonitriles 1 react in mild conditions with β‐trifluoroacetylvinyl ethers 2 to give the pyridine derivatives 4. The reaction involves the formation of the intermediate 3, that can be isolated when enol ether 2a is used.
Anodic cyanation of 1‐methylpyrazole
Authors: Yoshida Kunihisa , Toyo‐Oka Yoshimasa , Takeda Kazusada
Published: March 2009

The electrooxidation of 1‐methylpyrazole in methanol containing sodium cyanide produced 1‐methyl‐pyrazole‐4‐carbonitrile2and −5‐carbonitrile3in yields of 23 and 8%, respectively (2e‐oxidation products), together with 4‐methoxy‐1‐methylpyrazole‐5‐carbonitrile4(4e‐oxidation product, 4%).
2‐Aminopyridine derivatives as potential chiral auxiliaries
Authors: Parker Julie A. , Stanforth S. P.
Published: March 2009

2‐Bromopyridine and 2‐bromo‐6‐methoxymethylpyridine reacted with an excess of 1‐phenylethylamine at reflux giving the aminopyridine derivatives 3a and 3b respectively.
2,4,6‐trichloropyrimidine. Reaction with ethanolamine and diethanolamine
Authors: Delia Thomas J. , Stark Derron , Glenn Steven K.
Published: March 2009

2,4,6‐Trichloropyrimidine, 1, reacts with neutral nucleophiles, such as ethanolamine and diethanolamine, to produce both mono‐ and disubstituted derivatives resulting from replacement of either one (2 and 3) or two (4) chlorine atoms. The third chlorine could not be replaced by these nucleophiles. Failure of this final step was attributed to intramolecular hydrogen bonding of the nucleophiles.
The synthesis of 1,2,3,3a,4,5,6,11‐octahydro‐6,11a‐methano‐11aH‐benzo[4,5]cycloocta[1,2‐c]pyrroles. As new heterocyclic ring system
Authors: Ciganek Engelbert , Wright Ann S. , Nemeth Gregory A.
Published: March 2009

The synthesis of the novel 1,2,3,3a,4,5,6,11‐octahydro‐6,11a‐methano‐11aH‐benzo[4,5]cycloocta[1,2‐c]‐pyrrole system by acid‐catalyzed cyclization of cis‐3a‐benzyl‐3a,4,7,7a‐tetrahydro‐1H‐isoindole‐1,3(2H)‐diones is described.
Preparation and spectroscopic properties of 3‐acyl‐1,3,4‐oxadiazolines
Authors: Hearn Michael J. , Chanyaputhipong Phet‐Yoon
Published: March 2009

1,3,4‐Oxadiazolines I, in which substituent groups R1 through R4 may be varied through appropriate choice of precursor reactants, can be prepared in good yields and purity by convenient cyclizations of acyl‐hydrazones with anhydrides. The reactions can be effectively monitored by salient changes in the infrared spectra. The oxadiazolines are stable materials and thus serve as suitable derivatives for the chemical characterization of such tuberculostatic Schiff bases as IIa‐c.
Synthetic studies of two new condensed 1,3,5‐triazinium compounds of expected biological activity
Authors: Okide George B.
Published: March 2009

Two new triazinium perchlorates, 1 and 2, readily lose perchloric acid, especially in the presence of a base to afford the corresponding anhydrobases. These are easily methylated but the product from 1 appears not to retain the original electronic configuration.
Structures and fluorescence of secondary products produced from the cope‐knoevenagel reaction of 2‐phenylpropionaldehyde with methyl cyanoacetate
Authors: Nagai Wakatu , Hirata Yumiko , Kawai Masao , Tanaka Kiyoaki
Published: March 2009

The Cope‐Knoevenagel reaction of 2‐phenylpropionaldehyde (7) with methyl cyanoacetate (8) produced methyl (E)‐2‐cyano‐4‐phenylpent‐2‐enoate (9) and the two highly fluorescent secondary products, 2‐amino‐3‐carbomethoxy‐6‐phenyl‐4‐(1‐phenylethyl)pyridine (10) and 3‐cyano‐6‐phenyl‐4‐(1‐phenylethyl)‐2‐pyridone (11). The structure of 10 was determined by X‐ray crystallography while the structure of 11 was confirmed by the conversion of 9 into 11. The mechanism of their formation is discussed. Fluorescence of 10 and 11 and the related compounds are also described.
Synthesis and characterization of α,α'‐bis(aminomethyl)oligothiophenes and their related compounds
Authors: Muguruma Hitoshi , Saito Takashi , Sasaki Satoshi , Hotta Shu , Karube Isao
Published: March 2009

We have synthesized and characterized a series of novel compounds of α,α'‐bis(arninomethyl)oligothiophenes and their related compounds whose degree of polymerization spans two (dimer) to five (pentamer). The compounds presented in our studies are α,α'‐bis[(2,2,5,5‐tetramethyl‐1‐aza‐2,5‐disilacyclopenthyl)methyl]oligothiophene, α,α'‐bis(aminomethyl)oligothiophene dihydrochloride and α,α'‐bis(aminomethyl)oligothiophene. These compounds exhibit desired chemical activity while maintaining controllable electronic properties. The synthetic processes of the oligothiophenes are as follows: 2‐aminomethylthiophene is first ‘protected’ and the thiophene rings are coupled using standard Grignard methods. The protected groups are removed at the final stage of the reaction. The compounds show unique properties; for example α,α'‐bis(aminomethyl)oligothiophene dihydrochloride is soluble in water. The results of electronic spectra and titration are also presented.
Synthesis of 2H‐labeled alkoxyethyl phosphodiester (AZT) derivatives for solid‐state 2H‐NMR studies
Authors: Koufaki M. , Calogeropoulou T. , Mavromoustakos T. , Theodoropoulou E. , Tsotinis Andrew , Makriyannis Alexandras
Published: March 2009

Two specifically 2H‐labeled alkoxyethyl phosphodiester AZT derivatives 9 and 14 were synthesized. Pilot [2H]‐solid‐state nmr experiments on conjugate 14 demonstrated their usefulness in studying interactions with model or biological membranes.
Computational studies, synthesis and biological investigations of N‐[(p‐bromo)carboxyphenyl]dibenz[b,f]azepine
Authors: Martínez Roberto , Espinosa Rubén C. , Toscano Rubén A. , Cogordán J. Antonio , Arellano María Del Rosario , Angeles Enrique , Posada María Eugenia , Maya Beatriz , Martínez Luisa
Published: March 2009

With the aim to find new compounds with superior tranquilizer‐antidepressant activity theoretical studies, synthesis, X‐ray characterization and pharmacological test of the title compound were carried out. Theoretical studies suggested both tranquilizer and antidepressant activity and pharmacological tests proved it.
Synthesis and total 1H‐NMR assignment of [1]benzothieno‐[2,3‐c] [1,10]phenanthroline
Authors: Halverson Aileen Pfleider , Castle Lyle W.
Published: March 2009

The synthesis of [1]benzothieno[2,3‐c][1,10]phenanthroline (5) is described. It was obtained in four steps from known starting materials. The basic skeleton of the molecule and of the phenanthroline ring were formed via photocyclization. The total assignment of 1H‐nmr spectra was accomplished with the aid of two‐dimensional nmr methods.
Synthesis of 2‐(ω‐aminoalkyl)imidazolin‐4‐ones by ring chain transformation of lactam derivatives with α‐aminoamides
Authors: Rottmann Antje , Liebscher Jürgen
Published: March 2009

Reaction of N‐methylamides of biogenic (S)‐α‐amino acids 3 with lactam acetals 1 or lactim ethers 2 gives three types of products, i.e. N‐methyl‐α‐lactamiminoamides 5 by condensation, 2‐(ω‐aminoalkyl)imidazolin‐5‐ones 7 or 2‐(ω‐lactamimmoalkyl)imidazolin‐4‐ones 8 by ring chain transformation. All products represent novel optically active derivatives of biogenic α‐aminoacids.
Synthesis of flavone‐3‐sulfonylureas
Authors: Löwe Werner , Matzanke Norbert
Published: March 2009

The synthesis of new flavone‐3‐sulfonylurea derivatives is hereby described. The influence of a phenyl group in the 2‐position and an acetate group in the 8‐position at the chromone nucleus on the activity was studied. Only weak cytostatic activity of the new compounds was found.
The cycloaddition of diethyl chlorophosphite with norbornadiene: Synthesis and crystal structure of the cycloadduct.
Authors: Roussis Vassilios , Bænziger Norman C. , Wiemer David F.
Published: March 2009

In the presence of Lewis acids, diethyl phosphorochloridite reacts with norbornadiene to afford the tetracyclic phosphinate ester 3. The reaction is believed to involve formation of phosphenium ions stabilized only by alkoxy substituents. The cycloadduct of the reaction was characterized by its spectral data, by single crystal diffraction analysis of the parent acid, and 31P and 27Al nmr experiments.
Photocyclization of 2‐(naphth‐1‐yl)‐3‐(thien‐2‐yl)propenoic acid and the total assignment of the 1H‐ and 13C‐NMR spectra of the product
Authors: Tominagaxs Yoshinori , Castle Lyle W. , Castle Raymond N.
Published: March 2009

Photocyclization of the substituted 2‐(naphth‐1‐yl)‐3‐(thien‐2‐yl)propenoic acid (3) in the presence of iodine and air in a benzene‐cyclohexane mixture afforded a separable mixture of three compounds, phenanthro[2,1‐b]thiophene‐10‐carboxylic acid (4), phenanthro[2,1‐b]thiothene (5), and naphtho[1,8‐cde]‐thieno[3,2‐g][2]benzopyran (6)
Reactions of 2‐amino‐, 2‐alkylamino‐, and 2‐piperidino‐1‐azaazulenes with aryl and chlorosulfonyl isocyanates
Authors: Abe Noritaka , Matsuda Haruhiko , Sugihara Yoshikazu , Kakehi Akikazu
Published: March 2009

Reaction of 2‐amino‐1‐azaazulene with phenyl isocyanate gave 3‐phenyl‐2H‐3,4‐dihydro‐1,3,4a‐triazabenz[5,4‐a]azulene‐2,4‐dione. Reactions of 2‐alkylamino‐1‐azaazulenes with aryl isocyanates gave 2‐(N‐ethyl‐N′‐arylureido)‐1‐azaazulenes initially, which rearranged to N‐aryl‐2‐alkylamino‐1‐azaazulene‐3‐carboxamides and successive reaction with another molar amount of aryl isocyanate furnished uracil‐fuzed 1‐azaazulenes. Reaction of 2‐piperidino‐1‐azaazulene with aryl isocyanate gave N‐aryl‐2‐piperidino‐1‐azaazulene‐3‐carboxamide. Reaction of 2‐(substituted amino)‐1‐azaazulenes with chlorosulfonyl isocyanate gave 3‐cyano‐ and 3‐chloro‐2‐(substituted amino)‐1‐azaazulenes.
An AM1 and DFT‐AM1 computational study of methyl phenylpropiolate addition to 1‐phenyl‐3,4‐dimethylphosphole
Authors: Jursic Branko S. , Leblanc Blaise
Published: March 2009

The transition state structures for the addition of maleic acid anhydride and methyl phenylpropiolate to 1‐phenyl‐3,4‐dimethylphosphole were generated with the AM1 semiempirical method. The competitive transition state structures for 1,5‐phenyl rearrangement in 1‐phenyl‐3,4‐dimethylphosphole was also optimized with AM1. The energies were evaluated with the SVWN and Becke3LYP DFT methods using a 6‐31G(d) basis set. The reaction outcome based on the evaluated energies were discussed and compared with experimental observations.
Synthesis of an indole analog of magallanesine via the [1,2]‐meisenheimer rearrangement
Authors: Yoneda Ryuji , Kimura Tetsuya , Kinomoto Junko , Harusawa Shinya , Kurihara Takushi
Published: March 2009

Ring expansion of azetopyridoindole 11 via the [1,2]‐Meisenheimer rearrangement of the corresponding N‐oxide 12 gave azocinoindole 14, which was converted into the N‐benzoylenaminone 18 in 5 steps. Intramolecular cyclization of 18 was accomplished by a modified Heck reaction followed by reductive desulfonylation to provide the indole analog 2, 5H‐isoindolo[2′,1′;1,2]azocino[5,6‐b]indole, of magallanesine 1.
An electron‐impact mass spectral (EIMS) study of N‐1 and C‐6 carboxyalkyl‐ and alkoxycarbonylalkyl‐substituted derivatives of uracil
Authors: Wyrzykiewicz E. , Kazimierczuk Z.
Published: March 2009

The electron impact (EI) induced mass spectral fragmentation of seventeen, including seven newly synthesized, N‐1 and C‐6 carboxyalkyl‐ and alkoxycarbonylalkyl‐substituted derivatives of uracil and thymine was investigated. Fragmentation pathways are proposed on the basis of accurate mass and metastable transition measurements. The correlation between the intensities of the M+* and selected fragment ions of these compounds is discussed. The data obtained provide the basis for distinguishing isomers and metamers.
Synthesis of oxazolyl‐ and furanyl‐substituted imidazole hydrochlorides and methiodides
Authors: Boulos John , Schulman Jerome
Published: March 2009

Oxazolyl‐5‐ and furanyl‐2‐substituted imidazoles have been synthesized by coupling the two ring systems via the dipolar cycloaddition of tosyl methyl isocyanide to the corresponding oxazolyl and furanyl aldimines in basic media. These substituted oxazolyl and furanylimidazole bases obtained in this manner were then subjected to hydrogen chloride gas and to methyl iodide to form the corresponding hydrochlorides and methyliodides, respectively. All compounds were purified, characterized and then tested for muscarinic binding affinity. Biological test results revealed low muscarinic receptor affinity and selectivity.
Retro‐ene reactions in heterocyclic synthesis. IV. A new synthetic method for 6‐hydroxypyrimidin‐4(3H)‐ones and 1,3,5‐triazine‐2,4(1H,3H)‐diones
Authors: Ito Kunio , Miyajima Shingo
Published: March 2009

N‐t‐Butylbenzamidines 1 reacted with diphenyl phenylmalonate or diphenyl methylmalonate to give 6‐hydroxypyrimidin‐4(3H)‐ones 4 or 5. Amidines 1 on reaction with diphenyl imidodicarboxylate afforded 1,3,5‐triazine‐2,4(1H, 3H)‐diones 8.
New syntheses of 7‐substituted‐2‐aminothieno‐ and furo[3,2‐d]pyrimidines
Authors: Morris Philip E. , Elliott Arthur J. , Montgomery John A.
Published: March 2009

In a recent publication, we have the described the synthesis of 7‐substituted‐2‐amino‐1,5‐dihydro‐4H‐pyrrolo[3,2‐d]pyrimidin‐4‐ones which are potent inhibitors of the enzyme Purine Nucleoside Phosphorylase from the corresponding 3‐aminopyrroIe‐2‐carboxylate esters. A key step in the synthesis is condensation of the amino group with the highly reactive guanylating reagents 3 or 4 followed by annulation. The furo[3,2‐d]pyrimidin‐4‐one and thieno[3,2‐d]pyridin‐4‐one are closely related rings systems. However, these rings have not been reported in the literature with a 2‐amino, substituent which would arise from such guanylation reactions. In this report, the syntheses of the novel furans 5 are described based on our improved pyrrole synthesis (Scheme 1). The syntheses of the novel thiophenes 6 are described. The guanylation of 5 and 6 were studied and compared to 2. The 3‐amino group of 5 and 6 failed to react with 3 or 4 under mild acid catalysis; conditions under which 2 easily condensed. Guanylation was finally achieved by generating the carbodiimide intermediate of 3 under mercury catalysis affording the guanylated adducts which were converted to the novel 2‐aminothieno‐ and furo[3,2‐d]pyrimidin‐4‐ones 16.
Synthesis and biological activity of 1‐, 2‐ or 3‐Substituted benzothieno‐[2,3‐d]triazole derivatives structurally related to trazodone
Authors: Guerrera Francesco , Salerno Loredana , Sarvà Maria Concetta , Siracusa Maria Angela , Corsaro Antonino , Pistarà Venerando , Capasso Raffaele , Raso Giuseppina Mattace
Published: March 2009

A series of new 1‐, 2‐ and 3‐piperazinylbenzothieno[2,3‐d]triazole derivatives structurally related to Trazodone were prepared and tested for their antiserotonergic, antiadrenergic and antihistaminergic in vitro activities together with their analgesic in vivo activity by using Trazodone as the reference compound.
Regiospecific synthesis of 2‐substituted furanonaphthoquinones
Authors: Ohta Yasuo , Doe Matsumi , Morimoto Yoshiki , Kinoshita Takamasa
Published: March 2009

The naturally‐occurring furanonaphthoquinones 1a‐d have been synthesized from 3‐furancarboxylic acid and 2,3‐dimethoxybenzaldehyde via the Birch reduction‐elimination.