bluuebunny/crossref_metadata_2025 huggingface dataset:
2,2‐Dioxo‐1H‐thieno[3,4‐c][1,2]thiazines. Synthesis and some reactions of a new heterocycle
Authors: Fanghänel Egon , Bartossek Hagen , Baumeister Ute , Biedermann Matthias , Hartung Helmut
Published: March 2009

The first synthesis of substituted 2,2‐dioxo‐1‐phenyl‐1H‐thieno[3,4‐c][1,2]thiazines 2 and some of their reactions are achieved. Compounds 2 were prepared from the 3,5‐dimethyl‐1,1‐dioxo‐1,2‐thiazine‐4‐carbaldehydes 1 by reaction with sulfur and triethyl amine in dimethylformamide under mild conditions. They were characterized spectroscopically and by X‐ray structure analysis. The formylation, chlorination and oxidation of 2 are reported.
3‐Benzoyl‐3,4‐dihydro‐2H,5H‐1‐benzopyrano[4,3‐b]pyran‐5‐ones by condensation of 4‐hydroxycoumarins with enone mannich bases
Authors: Girreser Ulrich , Heber Dieter , Schütt Martin
Published: March 2009

Starting from 4‐hydroxycoumarins 4 and 1‐aryl‐2‐(dimethylaminomethyl)prop‐2‐en‐1‐ones 2 the title compounds 6 have been synthesized. The reaction is initiated by addition of the C‐3 carbon atom of 4‐hydroxycoumarin to the enone double bond of the Mannich base, subsequent deamination affords the intermediate 3‐(2‐benzoylallyl)‐4‐hydroxycoumarin 8, followed by ring closure. Depending on the reaction time, varying proportions of the ketones 6 and 8 are formed and support the mechanism defined. The spectroscopic data of all products unambiguously distinguish between the coumarin and the chromone structures in favor of the former.
Synthesis of isoindolo[1,3]benzoxazine derivatives through intramolecular arylation of N‐acyliminium ions
Authors: Hucher Nicolas , Daïch Adam , Decroix Bernard
Published: March 2009

[1,3]Benzoxazines annulated to isoindole as 3 and 4 have been synthesized in three steps from N‐chloromethylphthalimide 5 and substituted phenols 6. The key step was the acid‐catalyzed cyclization of ω‐carbinol lactams 8 and 9.
Studies on the synthesis of some dihydropyridine derivatives possessing calcium antagonistic activity
Authors: Kilcigil Gülgün Ayhan , Ertan Rahmiye , Özbey Süheyla , Kendi Engin
Published: March 2009

In this study, it is aimed to investigate the synthesis and the calcium antagonistic activity of some flavone derivatives which contain the 1,4‐dihydropyridine ring system at the A ring of the flavone nucleus. For this purpose we first synthesized 6‐formylflavone and then twelve 1,4‐dihydropyridine derivatives were synthesized by the reaction of 6‐formylflavone with alkylacetoacetates, acetoacetanilide and methyl or ethyl aminocrotonate. Conformational analysis was performed for compound 3a. The calcium antagonistic activity of compound 2a was examined using nifedipine as the reference compound.
Benzofuran systems. Regioselective bromination and some other reactions of 1‐(3‐benzofuranyl)‐2‐phenylethanones
Authors: Kwiecień Halina , Baumann Ernst
Published: March 2009

1‐[3‐(2‐Alkylbenzofuranyl)]‐2‐(3,5‐dibromo‐4‐hydroxyphenyl)ethanones 5a,b and 1‐[3‐(2‐alkylbenzofuranyl)‐2‐(3‐bromo‐4‐methoxyphenyl)ethanones 3a,b were readily prepared by selective bromination of hydroxy 1a,b and methoxy 1c,d ethanones, respectively. A successful method of O‐alkylamination of 5a with N‐(2‐chloroethyl)‐N,N‐diethylammonium chloride to 6a by a two‐phase reaction under phase transfer conditions has been applied. Lithium aluminium hydride reduction of the carbonyl group of 1b to carbinol 4b was carried out in good yields.
An alternative route to 2H‐naphtho[1,2‐b]thiete and its cycloaddition products
Authors: Rumpf Norbert , Gröschl Dieter , Meier Herbert , Oniciu Daniela C. , Katritzky Alan R.
Published: March 2009

2‐(1H‐Benzotriazol‐1‐ylmethyl)‐1‐naphthalenol (1) can be transformed in high yields to the corresponding thiol 4. Flash vacuum pyrolysis of 4 leads to 2H‐naphtho[1,2‐b]thiete (5). The benzotriazolyl group proved to be a good leaving group; however, a subsequent nitrogen extrusion takes place under flash vacuum pyrolysis conditions and cyclopentadienecarbonitriles 6a,b are formed by a ring contraction (Scheme 1). Cycloaddition reactions of 5 and dienophiles or heterodienophiles yield the naphtho‐condensed sulfur heterocycles 8, 10, 12 and 14 (Scheme 2).
Studies on the chemistry of thienoannelated o,n‐ and s,n‐containing heterocycles. 16. Synthesis of some thieno[1,4]thiazine derivatives with potential calcium antagonistic activity
Authors: Erker Thomas
Published: March 2009

Substituted thieno[1,4]thiazine derivatives have been synthesized. They are thienoanalogues of compound 3 [2], a potent cerebral protectant and calcium antagonist. Research activities concentrate on the preparation of structurally modified compounds of 3 to minimize its undesirable symptoms.
Transformations of methyl 2‐(2,2‐disubstituted‐ethenyl)amino‐3‐dimethylaminopropenoates. The synthesis of methyl 1‐heteroaryl‐1H‐imidazole‐4‐carboxylates
Authors: Selič Lovro , Stanovnik Branko
Published: March 2009

Transformations of intermediates 4, prepared from methyl 2‐(2,2‐disubstituted‐ethenyl)amino‐3‐dimethylaminopropenoates 2 and sterically hindered heteroarylamines 3, into methyl 1‐heteroaryl‐1H‐imidazole‐4‐carboxylates 7 are described.
Pyrrolo[3,2‐c][1,2,5]benzotriazocine: A new ring system
Authors: Passannanti Alessandra , Diana Patrizia , Barraja Paola , Lauria Antonino , Cirrincione Girolamo , Mingoia Francesco
Published: March 2009

A nucleophilic substitution reaction in the pyrrole series, achieved by a neutral nucleophile, led to the key intermediate 7 which by reduction and successive diazotization afforded the new ring system pyrrolo[3,2‐c][1,2,5]benzotriazocine 9 in good yield.
Photochemistry of mesoionic compounds. Photochemical conversion of 5‐azido‐1,3‐diaryltetrazolium salts to novel tricyclic mesoions with a tetrazolo[1,5‐a]benzimidazole skeleton
Authors: Araki Shuki , Hattori Hiromi , Shimizu Noriyuki , Ogawa Koji , Yamamura Hatsuo , Kawai Masao
Published: March 2009

A new type of tetrazolium‐5‐amide mesoions 2 with a tricyclic tetrazolo[1,5‐a]benzimidazole skeleton has been synthesized via photolysis of 5‐azido‐1,3‐diaryltetrazolium salts 1.
Quaternization and dequaternization of pyrazoles in solvent‐free conditions: Conventional heating versus microwave irradiation
Authors: Díez‐Barra Enrique , De La Hoz Antonio , Sánchez‐Migallón Ana , Elguero José
Published: March 2009

We report a study on the quaternization and dequaternization of pyrazoles by conventional heating and microwave irradiation in solvent‐free conditions. Microwave irradiation produces an acceleration in the quaternization rate and a rapid equilibration between quaternized and non quaternized products. Dequaternization is also more rapid and a change on the selectivity is observed using symmetric pyrazolium salts.
Studies on pyrrolidinones. Synthesis of 1,2,3,5,11,11a‐hexahydroindolizino[7,6‐b]indole‐3,11‐dione
Authors: Ebrik Sahar Al Akoum , Legrand Anne , Rigo Benoît , Couturier Daniel
Published: March 2009

Condensation of N‐trimethylsilylindole with methyl N‐trimethylsilyloxymethylpyroglutamate is the best method to obtain methyl N‐indolylmethylpyroglutamate. Friedel‐Crafts cyclization of the corresponding acid yields a new ketone (1,2,3,5,11,11a‐hexahydroindolizino[7,6‐b] indole‐3,11‐dione).
Synthesis of piperidine analogs of 1‐(3‐chlorophenyl)piperazine, a well known serotonin ligand
Authors: Rádl Stanislav , Hezký Petr , Taimr Jan , Proška Jan , Krejčí Ivan
Published: March 2009

Synthesis of arylpiperideines 3a‐3d and arylpiperidines 4a‐4d as analogs of a well known serotonin ligand 1‐(3‐chlorophenyl)piperazine is reported. Starting aryllithium derivatives were treated with 1‐methyl‐piperdin‐4‐one to provide the corresponding hydroxy derivatives 6a and 6b.N‐Methylpiperideine derivatives 3a and 3c were obtained by their dehydration while the correspondingN‐unsubstituted compounds 3b and 3d were prepared indirectly by a three‐step procedure. Hydrogenation of piperideine 3a provided the corresponding piperidine derivative 4a which after demethylation yielded 4b. Similar 4‐pyridyl derivatives 4c and 4d were prepared by a similar strategyviathe corresponding methoxy derivatives.
Structural identification of a novel degradant of the antibiotic pirlimycin formed under thermal stress conditions
Authors: Crow Frank W. , Duholke Wayne K. , Martin Gary E. , Smith Richard F. , Thamann Thomas J. , Cooper Anne M. , Hallberg John W. , Blinn James R. , Chidestere Constance G.
Published: March 2009

The structure of a novel, thermally‐induced degradant of the antibiotic pirlimycin is presented. The degradant was discovered during thermal stress stability testing of pirlimycin. The structure was determined using high resolution mass spectrometry, ms/ms fragmentation, and extensive nmr studies including a combination of homonuclear TOCSY and gradient, inverse‐detected 2‐D nmr experiments which included GHSQC and GHMBC. All nmr, high resolution ms and ms/ms fragmentation data are consistent with loss of a molecule of HCl during a ring closure involving one of the hydroxyl moieties from the sugar portion of the molecule forming a tetrahydrofurano[3,2‐b]perhydropyran ring structure. The X‐ray crystal structure is reported for pirlimycin. Using this structure molecular modelling studies are performed which demonstrate the feasibility of the formation of the new structure.
Hydrobromic acid‐dimethyl sulfoxide reagent for dealkylation of 5,10‐dialkyl‐5,10‐dihydrophenazines: Synthesis of 10‐alkyl‐2(10H)‐phenazinones
Authors: Sugimoto Akira , Yoshino Yasuyuki , Watanabe Ryo , Mizuno Kazuhiko , Uehara Kaku
Published: March 2009

By the reaction of 5,10‐dialkyl‐substituted 5,10‐dihydrophenazine with hydrobromic acid in dimethyl sulfoxide at 90–110°, 10‐alkyl‐2(10H)‐phenazinone was obtained as a major product. Brominated dihydrophenazine was isolated in the case of 1,6‐dichloro‐5,10‐dimethyl‐5,10‐dihydrophenazine.
Synthesis of spiropyrazolines via 1,3‐dipolar cycloaddition of nitrilimines
Authors: Jedlovská Eva , Fišera Lubor , Lévai Albert , Tóth Gábor , Balázs Barbara
Published: March 2009

The regio‐ and stereoselective synthesis of spiropyrazolines 7 and 8 via 1,3‐dipolar cycloaddition of C‐2‐(5‐nitrofuryl)‐N‐methylnitrilimine, C‐2‐(5‐nitrofuryl)‐N‐phenylnitrilimine and C‐4‐nitrophenyl‐N‐methyl‐nitrilimine to (E)‐3‐benzylidenechromanone (1), ‐1‐thiochromanone 2, ‐1‐tetralone 3 and (E)‐3‐benzylidene‐flavanone (4) is reported. The relative configuration and conformations of the spiropyrazolines were elucidated by various nmr methods.
Microwave synthesis and anticonvulsant activity of 2‐benzyl‐1(2H)‐phthalazinones
Authors: Kornet Milton J. , Shackleford George
Published: March 2009

Microwave irradiation of 1(2H)‐phthalazinone with benzyl halides and potassium carbonate in dimethyl‐formamide afforded 2‐benzyl‐1(2H)phthalazinones in modest yields. These products were tested in mice and rats in maximal electroshock and pentylenetetrazole seizure models for anticonvulsant activity, and in the rotorod test for neurotoxicity. A majority of the compounds exhibited anticonvulsant protection. The p‐aminobenzyl analog 1f was the most active compound in the maximal electroshock assay; it's ED50 value was 19.46 mg/kg and the TD50 was 61.35 mg/kg. In the rat, the values were 3.71 mg/kg and >125 mg/kg, respectively.
Direct conversion to 2‐phenyl‐4‐quinolones via a 4‐alkoxyflavylium salt from a naturally occurring flavanone
Authors: Sato Shingo , Kumagai Hironobu , Matsuba Shigeru , Kumazawa Toshihiro , Onodera Jun‐Ichi , Suzuki Masanobu
Published: March 2009

A flavanone, in which a hydroxyl group at the 5‐position was protected with a methyl group, converted to the corresponding 5‐methoxy‐2‐phenyl‐4‐quinolone via flavylium salt under mild conditions. Flavanone‐O‐rhamnoglucoside, naringin, was also converted to 5‐methoxy‐2‐phenyl‐4‐quinolon‐7‐O‐rhamnoglucoside in the same way in an overall 25% yield.
The azomethine ylid strategy for β‐lactam synthesis
Authors: Gallagher Timothy
Published: March 2009

A summary of the development, mechanistic features, and scope of the azomethine ylid strategy for the synthesis of a variety of bicyclic β‐lactam derivatives, including carbapenams, carbapenems as well as heteroatom substituted variants, is presented.
N‐tert‐butoxycarbonyl‐N‐substituted hydrazines in SNAr displacements. Synthetic pathways to N‐1‐substituted anthrapyrazoles, aza‐anthrapyrazoles and aza‐benzothiopyranoindazoles
Authors: Oliva Ambrogio , Ellis Michael , Fiocchi L. , Menta Ernesto , Krapcho A. Paul
Published: March 2009

The synthesis of several N‐tert‐butoxycarbonyl(Boc)‐protected‐N‐substituted hydrazines has been accomplished. The use of these protected hydrazines in SNAr substitutions leads to products in which the most nucleophilic nitrogen displaces the leaving group. Treatment of these compounds with trifluoroacetic acid readily removes the Boc‐protecting group and the intermediates readily undergo cyclizations to yield N‐1‐substituted aza‐benzothiopyranoindazoles, anthrapyrazoles and aza‐anthrapyrazoles. Side chain buildup was employed in the synthesis of several aza‐anthrapyrazoles.
Syntheses of chiral bishomodiazacalix[4]arenes incorporating amino acid residues: Molecular recognition for racemic ammonium ions by the macrocycles possessing tyrosine residues
Authors: Ito Kazuaki , Ohta Takanori , Ohba Yoshihiro , Sone Tyo
Published: March 2009

Chiral bishomodiazacalix[4]arenes containing amino acid residues were prepared. The 1H and 13C nmr spectra indicated that the macrocycles preferably adopted a cone conformation, which suggested that the cyclophane moiety was in a chiral twisted form. Circular dichroism spectra supported the existence of the chirality of the cyclophane unit, and showed that intramolecular hydrogen bonding plays an important role in the transmission of the chirality from the amino acid residues to the cyclophane moiety. Macrocycles bearing a tyrosine residue have a π‐base cavity large enough to include the ammonium ion, and can serve as a shift reagent for the racemic ammonium ions upon complexation during a 1H nmr analysis.
Synthesis of new functionalized imidazo[2,1‐b]thiazoles and thiazolo[3,2‐a]pyrimidines
Authors: Peterlin‐Mašič Lucija , Malešič Mateja , Breznik Matej , Krbavčič AleŠ
Published: March 2009

5‐Oxo‐5H‐[1,3]thiazolo[3,2‐a]pyrimidine‐6‐carboxylic acid (4), and 6‐methylimidazo[2,1‐b]thiazole‐5‐carboxylic acid (17) were reacted with amines 6a‐i by the reaction with oxalyl chloride and N, N‐di methyl‐formamide as a catalyst into primary and secondary amide derivatives 7‐14 and 19‐22. From compound 24 N,N'‐disubstituted ureas 26, 27 and perhydroimidazo[1,5‐c]thiazole 29 derivatives of imidazo[2,1‐b]thiazole were prepared. By nmr analysis of compound 29, the existence of two stereoisomers resulting from both optical, due to centre of chirality at C7′a, and conformational isomerism, due to restricted C5N6′ bond rotation were proved.
Studies on pyrrolidinones. Preparation of 1,5,6‐10b‐tetrahydro‐2H‐pyrrolo[1,2‐c]quinazoline‐3‐ones from pyroglutamic acid
Authors: Ghammarti Samira El , Rigo Benoít , Mejdi Hechmi , Hénichart Jean‐Pierre , Couturier Daniel
Published: March 2009

Tetrahydro‐2H‐pyrrolo[1,2‐c]quinazoline‐3‐ones are easily obtained from the Friedel‐Crafts cyclization of N‐arylaminomethyl pyroglutamic acids. This reaction occurrs via an acyliminium salt formed by decarboxylation of the acid function.
An expedient synthesis of 2,3‐dihydro‐5,6‐dimethoxy‐3‐methylsulfonamido‐1,2‐benzisothiazole‐1,1‐dioxide via intramolecular sulfamoyl michael addition
Authors: Bassin J. P. , Al‐Nawwar K. , Frearson M. J.
Published: March 2009

A simple method of introducing a sulfamoylmethyl group on carbon‐3 in 1,2‐benzisothiazole‐1,1‐dioxide is described.
Synthesis of five nevirapine metabolites
Authors: Grozinger Karl G. , Byrne Denis P. , Nummy Laurence J. , Ridges Michael D. , Salvagno Annette
Published: March 2009

Nevirapine (1) is a non‐nucleoside reverse transcriptase inhibitor marketed for HIV treatment by Boehringer Ingelheim as Viramune® since 1996.In vitrostudies of nevirapine biotransformation using human liver microsomes demonstrated the formation of five major metabolites. This paper describes the syntheses of these metabolites.
Synthesis of azaindenoquinoline analogs of amsacrine
Authors: Barret R. , Ortillon S. , Mulamba M. , Laronze J. Y. , Lévy J. , Trentesaux C.
Published: March 2009

Five azaindenoquinolines were synthesized in order to study their antitumoral activity.
On triazoles XLI [1]. Synthesis of meso‐ionic [1,2,4]triazolo[5,1‐c]thiadiazoles
Authors: Reiter József , Barkóczy József , Argay Gyula , Kálmán Alajos
Published: March 2009

Type 6 meso‐ionic [1,2,4]triazolo[5,1‐c]thiadiazoles were synthesised by oxidation of the corresponding N‐methyl‐N'‐(substitutedbenzal)‐5‐amino‐3‐substituted‐1,2,4‐triazol‐1‐yl)thiohydrazide (3) type bases or their [1,2,4]triazolo[5,1‐d][1,2,3,6]tetrazepin‐5‐thion (4) type ring tautomers. Besides spectroscopical evidence a preparative proof of their structure was also provided. X‐ray diffraction analysis of 3‐methylthio‐6‐morpholino‐1,2,4‐triazolo[5,1‐c]thiadiazole (8) showed quite unusual bond lengths for the N1‐S and S‐C3 bonds of the thiadiazole ring proving the meso‐ionic character of these derivatives unequivocally.
Synthesis of thiazole, oxazole and heterocyclic ring‐substituted 1,2‐dioxanes
Authors: Sakata Michiharu , Shirakawa Yumi , Kamata Nobuhito , Sakaguchi Yuko , Nishino Hiroshi , Ouyang Jie , Kurosawa Kazu
Published: March 2009

The reactions of 4‐bromoacetyl‐3‐methoxy‐3‐methyl‐6,6‐diphenyl‐1,2‐dioxane with thioureas or thioamides gave 3‐methoxy‐3‐methyl‐6,6‐diphenyl‐4‐(4‐thiazolyl)‐1,2‐dioxanes in 63–90% yields. The similar reaction of 4‐bromoacetyl‐3‐methoxy‐3‐methyl‐6,6‐diphenyl‐1,2‐dioxane with acetamide gave 3‐methoxy‐3‐methyl‐4‐(2‐methyl‐4‐oxazolyl)‐6,6‐diphenyl‐1,2‐dioxane in 39% yields. The reactions of 4‐bromoacetyl‐3‐methoxy‐3‐methyl‐6,6‐diphenyl‐1,2‐dioxane with 3‐alkyl‐4‐amino‐5‐mercaptot[1,2,4]triazoles yielded 3‐methoxy‐3‐methyl‐6,6‐diphenyl‐4‐[3‐(5‐alkyl[1,2,4]triazolo[3,4‐b]‐2,3‐dihydro‐6H‐[1,3,4]thiadiazinyl)]‐1,2‐dioxanes in moderate yields (43–46%).
A facile synthesis and antimicrobial activity of 2,10‐dichloro‐6‐(aryloxy/thiophenoxy)‐4,8‐dinitrodibenzol[d,g][1,3,6,2]‐dioxathiaphosphocin‐ 6‐oxides
Authors: Reddy C. Devendranath , Berlin K. Darrell , Rao L. Nagaprasada
Published: March 2009

Novel 6‐substituted 2,10‐dichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphocin‐6‐oxides 4 were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenyl sulfide (2) with different aryl phosphorodichloridates, trichloromethylphosphonic dichloride and O‐2‐chloroethyl phosphoryldichloride (3) in the presence of triethylamine at 55–60°. Some of these compounds are prepared by reacting the monochloride, 2,6,10‐trichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphoein‐6‐oxide (5) in situ with substituted phenols and thiols. 5 is prepared by condensing 2 with phosphorus oxychloride. The 1H nmr chemical shifts of the dibenzodioxathiaphosphocin moiety indicates the presence of more than one conformer in solution. However the presence of more than one conformer in each example cannot be entirely eliminated. Interestingly 4d on oxidation to 12‐sulphone by H2O2 in acetic acid medium yielded only 12‐sulphoxide 6a. The ir, 1H, 13C, 31P nmr and mass spectral data are discussed. Some of these compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and antibacterial activity on Bacillus subtilis and Klebsiella pneumoniae. A few of them possess significant activity.
Synthesis and analgesic‐antiinflammatory activities of ethyl 2‐[3‐(1‐phenoxy(methoxy)carbonyl‐4‐aryl‐(alkyl)‐1,4‐dihydropyridyl)]acetates
Authors: Agudoawu Sammy A. , Knaus Edward E.
Published: March 2009

Reaction of ethyl 2‐(3‐pyridyl)acetate 4a or ethyl 2‐methyl‐2‐(3‐pyridyl)acetate 4b, with phenyl chloroformate or methyl chloroform ate, afforded the intermediate pyridinium salt 5 which undergoes regioselective nucleophilic attack at C‐4 upon reaction with a Grignard reagent in the presence of a cuprous iodide catalyst at −23° to yield the corresponding ethyl 2‐[3‐(1‐phenoxy(methoxy)carbonyl‐4‐aryl(alkyl)‐1,4‐dihydropyridyl)]acetates 6a‐f in 64–96% chemical yield. No product arising from reaction of the ester substituent of the pyridinium salt 5 with the Grignard reagent was observed. The 1H nmr spectra of 6a‐f exhibited dual resonances for the 1,4‐dihydropyridyl H‐2, H‐5 and H‐6 protons at 25° in deuteriochloroform. These dual resonaces were attributed to two different rotameric configurations resulting from restricted rotation about the nitrogen‐to‐carbonyl carbamate bond due to its double bond character. Compound 6 generally exhibited superior analgesic and antiinflammatory activities, compared to the reference drugs aspirin and ibuprofen, respectively. These structure‐activity correlations indicate the 1,4‐dihydropyridyl ring system present in 6 is a suitable bioisostere for the aryl (heteroaryl) ring present in aryl(heteroaryl)acetic acid non‐steroidal antiinflammatory drugs.
Synthesis of bis(indolylmaleimide) macrocycles
Authors: Mahboobi Siavosh , Dechant Irene , Reindl Hans , Pongratz Herwig , Popp Alfred , Schollmeyer Dieter
Published: March 2009

The synthesis of a novel class of macrocyclic bis(indolylmaleimides) is reported. The key step involves the intermolecular connection of 2,2′‐bridged indoles with 3,4‐dibromo‐2,5‐dihydro‐1H‐2,5‐pyrroledione (dibromomaleimide) derivatives. The bis(indolylmaleimides) afforded by this method were further processed by intramolecular nucleophilic substitution of the remaining bromo substituents forming flexible N‐substituted macrocycles (9a‐9j, 10a‐10e) and, by connecting both maleimides, semi rigid macrocycles (7a‐7xx).
An efficient O‐dealkylation procedure for the synthesis of (3as,cis)‐1,2,3,3a,8,8a‐hexahydro‐1,3a,8‐trimethylpyrrolo[2,3‐b]indol‐5‐yl‐3,4‐dihydro‐2(1H)‐isoquinolinecarboxylate
Authors: Gao Zhongli , Lee Thomas B. K. , Rauckman Barbara S.
Published: March 2009

The title compound is synthesized in high yields and purity from (‐)‐eserethole (2a) via a lithium bromide catalyzed hydrobromic acid O‐dealkylation procedure as the key step.
A novel and facile reaction toN6‐alkylated adenosineviabenzotriazole as a synthetic auxiliary
Authors: Afify Hanan M. N. M. , Pedersen Erik B. , Zahran Magdy A.
Published: March 2009

The reaction of benzotriazole with aliphatic, aromatic or heteroaromatic aldehyde and adenosine leads to a benzotriazole adduct which is reduced with sodium borohydride to the correspondingN6‐alkylated adenosine derivatives. This procedure is also utilized in a new route toN6‐(3‐iodobenzyl)adenosine‐5′‐N‐methyluronamide (IB‐MECA) which is considered an important adenosine agonist at A3adenosine receptors.
Synthesis of new 2,2′‐disubstituted 5,5′‐dimethyl‐4,4′‐bitriazoles and 2‐(4‐Triazolyl)quinoxalines
Authors: Invidiata Francesco Paolo , Aiello Stefania , Furno' Giancarlo , Aiello Enrico , Simoni Daniele , Rondanin Riccardo
Published: March 2009

Thermal rearrangement of 3‐acylisoxazole arylhydrazones allowed facile preparation of 2H‐1,2,3‐triazoles which were firstly reacted with isoamyl nitrite and then with an opportune arylhydrazine to produce the corresponding α‐hydroxyiminohydrazones 8a‐h. The reaction of compounds 8a‐h with phosphorus pentachloride afforded the desired 4,4′‐bitriazoles 1a‐h. The α‐hydroxyiminoketone derivative 7 or the α‐diketone 14 reacted easily with 1,2‐phenylenediamine to afford 1,2,3‐triazoles 2a‐c bearing the quinoxaline moiety at position 4. Improved yields of the quinoxalines 2a‐c were obtained when 1,2‐phenylenediamine was reacted with the dioxime 15.
Synthesis of novel 5H, 11H‐pyrido[2′,3′:2,3]thiopyrano[4,3‐b]‐indoles by fischer‐indole cyclization
Authors: Da Settimo Antonio , Marini Anna Maria , Primofiore Giampaolo , Da Settimo Federico , Salerno Silvia , La Motta Concettina , Pardi Gianluca , Ferrarini Pier Luigi , Mori Claudio
Published: March 2009

The synthesis of the title compounds 5H, 11H‐pyrido[2′,3′:2,3]thiopyrano[4,3‐b]indoles was accomplished by the Fischer indole cyclization of some 2,3‐dihydrothiopyrano[2,3‐b]pyridin‐4(4H)‐one phenylhydrazones and 7‐methyl‐2,3‐dihydrothiopyrano[2,3‐b]pyridin‐4(4H)‐one phenylhydrazones. The synthesis of the new 2,3‐dihydrothiopyrano[2,3‐b]pyridin‐4(4H)‐one, which was used as one of the starting compounds, is also described.
A novel and direct synthetic route to substituted 1,5‐dihydro‐4H‐[1]benzopyrano[4,3‐b]pyridine‐4,5‐diones
Authors: Světlík Jan , Prónayová Nad'A , Hanuš Vladimír
Published: March 2009

The condensation of 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one and substituted 2‐hydroxybenzaldehydes with ammonium acetate gave the title heterocycles. Synthesis of 1,5‐dihydro‐2‐methyl‐4H‐[1]naphtho‐[1′,2′:5,6]pyrano[4,3‐b]‐pyridine‐4,5‐dione is also described. A reaction mechanism is discussed.
Synthesis of 2‐amino‐7,8‐dihydro‐6(5H)‐quinazolinone, 2,4‐diamino‐7,8‐dihydro‐6(5H)‐quinazolinone, 5,6,7,8‐tetrahydro‐2,6‐quinazoline‐diamine and 5,6,7,8‐tetrahydro‐2,4,6‐quinazolinetriamine derivatives
Authors: Marinko Petra , Obreza AleŠ , Peterlin‐Mašič Lucija , Krbavčič AleŠ , Kikelj Danijel
Published: March 2009

N‐(2‐Amino‐5,6,7,8‐tetrahydro‐6‐quinazolinyl)acetamide (9) and N‐(2,4‐diamino‐5,6,7,8‐tetrahydro‐6‐quinazolinyl)acetamide (6) were synthesized from N‐(4‐oxocyclohexyl)acetamide (5) as novel peptidomimetic building blocks. With similar purpose, N‐(6‐oxo‐5,6,7,8‐tetrahydro‐2‐quinazolinyl)acetamide (18) and N‐[2‐(acetylamino)‐6‐oxo‐5,6,7,8‐tetrahydro‐4‐quinazolinyl]acetamide (14) were prepared from cyclohexane‐1,4‐dione monoethylene ketal (11).
Hydrolysis of methylthiazolopyridines. X‐ray crystal structure of 3‐acetamido‐2(1H)‐pyridinethione
Authors: Giorgi Gianluca , Salvini Laura , Ponticelli Fabio
Published: March 2009

Hydrolysis of 2‐methylthiazolo[5,4‐b]pyridine resulted in ring opening of the thiazole and formation of 3‐acetamido‐2(1H)‐pyridinethione whose X‐ray crystal structure has been determined.
Porphyrin derivatives: Synthesis and potential applications
Authors: Cavaleiro José A. S. , Neves Maria G. P. M. , Tomé Augusto C. , Silva Artur M. S. , Faustino Maria A. F. , Lacerda Paula S. , Silva Ana M. G.
Published: March 2009

Porphyrin‐porphyrin and porphyrin‐chlorin dimers have been synthesized and evaluated for their photo‐physical and in vivo photodynamic therapy properties. Two of them can become potential new photosensitizers. Study of the reactivity of meso‐tetraaryl porphyrins, as dienophiles, in Diels‐Alder transformations and as dipolarophiles in 1,3‐dipolar cycloadditions, has been undertaken. New synthetic methodologies for certain chlorin, bacteriochlorin and isobacteriochlorin type macrocycles, with potential biological significance, have been established.
Novel heterocyclic construction via dipolar cycloadditions to 1,2‐dicarbonyl compounds
Authors: Nair Vijay , Sheela K. C. , Radhakrishnan K. V. , Vinod A. U. , Nair J. Somarajan , Rajesh C. , Treesa P. M.
Published: March 2009

The reactivity of o‐quinones and other 1,2‐diones towards a variety of dipolar species viz‐, nitrile oxides, carbonyl ylides, betaines and mesoionic compounds has been investigated. In most cases, these reactions occur with the participation of C=O group as the dipolarophile leading to the synthesis of novel heterocyclic compounds.
Reactivity studies of ethyl(Z)‐N‐(2‐amino‐1,2‐dicyanovinyl) formimidate with carbonyl compounds in the presence of base
Authors: Joséalves M. , Carvalho M. Alice , Fernanda M. , Proença J. R. P. , Booth Brian L.
Published: March 2009

The reaction of ethyl(Z)‐N‐(2‐amino‐1,2‐dicyanovinyl)formimidate6with carbonyl compounds in the presence of triethyl amine occurs with formation of the Schiff s base and intramolecular hydrolysis of the adjacent cyano group to give the alkylideneamino derivatives8a‐f. When the α‐carbon of the ketone has at least one proton, the prolonged contact of8a‐fwith triethylamine causes intramolecular cyclization between this carbon and the imidate carbon atom to form a seven membered ring. This is followed by cyclization of the cyano and amido groups, leading to the pyrrolo[4,3‐b][1,4]diazepines9. If a strong base is used the first ring to be formed is the pyrrole ring as evidenced in the reaction of8awith 1,8‐diazabicyclo[5.4.0]undec‐7‐ene leading to14. The subsequent addition of methyl amine to the reaction mixture, caused cleavage of the alkylideneamino unit and formation of the amidine function from the imi date (15). The addition of acid to the imidates8aand8fled to the diazepine compounds10aand10frespectively. A suspension of compound8ein ethanol and triethylamine evolved to a pyrazinone structure12under kinetic conditions (4 hours, room temperature) and to the pyrrolo[4,3‐b][1,4]diazepine9eunder thermodynamic conditions (48 hours, room temperature).
Formation and cycloaddition reactions of ferrocenyl nitrones
Authors: Coutouli‐Argyropoulou Evdoxia , Sabbas Ioannis , Konarski Stefan
Published: March 2009

Ferrocenyl nitrones derived from aldehydes or oximes react with electron deficient alkenes to give ferrocenylisoxazolidines. 5‐Methoxycarbonylisoxazolidines are further transformed to ferrocenyl‐pyrrolidinones by reductive cleavage. The regio‐ and stereoselectivity of the reactions are discussed.
On the way to unsymmetrical terpyridines carrying carboxylic acids
Authors: Raboin Jean‐Christophe , Kirsch Gilbert , Beley Marc
Published: March 2009

For the first time arv unsymmetrical 2,2′‐6′2″‐terpyridine carry two carboxylic acids has been prepared using Hantzsch's method for pyridine ring formation and furan as a latent carboxylic group.
A series of diarylsubstituted oximes as potential substrate for new aldose reductase inhibitors
Authors: Rakowitz Dietmar , Heinisch Gottfried , Lukavsky Peter , Kiendler Sigrid , Trenkwalder Cornelia , Barlocco Daniela , Rastelli Giulio , Costantino Luca
Published: March 2009

In the course of our research aimed at the discovery of new compounds acting as aldose reductase inhibitors, we tested a series of some (E)‐ and (Z)‐ω‐[[(aryldiazinylmethylene)amino]oxy]alkanoic acids, which were found to have moderatein vitroinhibitory activity. On this basis we have now prepared several new derivatives modified both at the length of the chain and at its terminal carboxylic group, together with compounds carrying various substituents at the phenyl ring. This paper describes their synthesis and biological properties.
The synthesis of novel nonclassical reversed bridge quinazoline antifolates as inhibitors of thymidylate synthase
Authors: Gangjee Aleem , Kotharé Mohit , Kisliuk Roy L.
Published: March 2009

2‐Amino‐6‐methyl‐5‐(pyridin‐4‐ylsulfanyl)‐3H‐quinazolin‐4‐one (3, AG337) a lipophilic thymidylate synthase inhibitor, is currently in clinical trials as an antitumor agent. On the basis of the crystal structure of 3 and the classical inhibitor 10‐propargyl‐5,8‐dideazafolic acid (1, PDDF) with thymidylate synthase, we designed and synthesized a series of nonclassical 2‐amino‐6‐substituted‐3H‐quinazolin‐4‐ones 4–13, with a variety of electron withdrawing groups in the side chain (with the exception of compound 4). Molecular modeling indicates that these reversed bridge (N9–C10) 6‐substituted analogues orient their side chain C10‐substituent such that it lies between that of 1 and 3. These compounds were obtained by reduc tive amination of 6‐aminoquinazoline 16 and the appropriate aryl aldehyde 17 or aryl ketone 18. For ana logues 11–13, the yield depended on the substitutents on the aryl ketone 18 (comparison of 11 and 13). With the exception of analogue 13, all the compounds in the series were poor inhibitors of thymidylate synthase from Lactobacillus casei, Pneumocystis carinii and human sources.
Practical synthesis of (S)‐7‐(2‐isopropylamino)ethylcamptothecin hydrochloride, potent topoisomerase I inhibitor
Authors: Ahn Soon Kil , Choi Nam Song , Jeong Byeong Seon , Kim Kye Kwang , Journ Duck Jin , Kim Joon Kyum , Lee Sang Joon , Kim Jung Woo , Hong Chung , Jew Sang‐Sup
Published: March 2009

A practical semi‐synthetic method of (S)‐7‐(2‐isopropylamino)ethylcamptothecin hydrochloride has been developed. The Mannich reaction of (S)‐7‐methylcamptothecin with isopropylamine hydrochloride in dimethyl sulfoxide as a formaldehyde source gave the desired product in moderate yield.
Quantitative synthesis and NMR characterization of perhydro‐1,3,5‐tris(alkylpolyalkoxyl)‐S‐triazines
Authors: Wolak Thomas J. , Wollenberg Kurt F. , Adams Paul E.
Published: March 2009

Unhindered polyalkoxylated primary amines, upon treatment with an equimolar equivalent of formalde hyde, cyclized quantitatively to afford perhydro‐1,3,5‐s‐triazines. This sereis of derivatives, based upon primary amine terminated poly(propylene and butylene oxides), possessed a molecular weight range of 1,900–5,800. Structure confirmation was accomplished by gel permeation chromatography and 2D nmr spectroscopy methods.
Synthesis of pyrrolo[2,1‐a]phthalazines by 1,3‐dipolar cycloaddition of phthalazinium N‐ylides with alkenes in the presence of tetrakis‐pyridine cobalt (II) dichromate
Authors: Zhou Jian , Hu Yuefei , Hu Hongwen
Published: March 2009

We describe here, for the first time, that 1‐cyano‐3‐benzoyl‐1,2,3,10b‐tetrahydropyrrolo[2,1‐a]phthalazine (8), prepared by 1,3‐dipolar cycloaddition of 2‐phenacyl phthalazinium bromide (6a) with acrylonitrile (7a), can be aromatized by tetrakis‐pyridine cobalt (II) dichromate (TPCD) to give 1‐cyano‐3‐benzoylpyrrolo[2,1‐α]phthalazine (9a) in good yield. Furthermore, a general and convenient one‐pot procedure for preparation of pyrrolo[2,1‐α]phthalazines (9a‐p) was developed by 1,3‐dipolar cycloaddition of phthala zinium N‐ylides (6a‐c) with alkenes (7a‐g) in the presence of TPCD.
Syntheses of new unsymmetrically dodecakis(trifluoroethoxy)‐substituted metallophthalocyanines by a palladium‐catalyzed cross‐coupling reaction
Authors: Tian Minquan , Wada Tatsuo , Sasabe Hiroyuki
Published: March 2009

Novel unsymmetrical vanadyl and zinc dodecakis(2,2,2‐trifluoroethoxy)phthalocyaninates with an iodo group were synthesized by a statistical condensation route. The palladium‐catalyzed coupling reaction between such monoiodinated metallophthalocyanines and terminal acetylenic derivatives gave various new unsymmetrically dodecakis(2,2,2‐trifluoroethoxy)‐substituted metallophthalocyanines with extended exocyclic π‐conjugation. Unsymmetrical zinc dodecakis(2,2,2‐trifluoroethoxy)phthalocyaninate with a nitro group was also prepared for comparison. All the target phthalocyanines were separated by common col umn chromatography and characterized by elemental analysis, ir and 1H‐nmr, uv‐visible and fast‐atombombardment mass spectroscopy.
A new efficient synthesis of 3‐(hydroxymethyl)‐4H‐chromen‐4‐ones
Authors: Bolós Jordi , Loscertales Teresa , Nieto Joan , Sacristán Aurelio , Ortiz José A.
Published: March 2009

An efficient and versatile synthesis of variously substituted 3‐(hydroxymethyl)‐4H‐chromen‐4‐ones is reported. The compounds are prepared by hydroxymethylation of the precursor 2‐hydroxy‐4‐chromanones followed by acid dehydration.
A new synthesis of N‐alkyl pyrazolidine‐3,5‐diones and tetrahydropyridazine‐3,6‐diones
Authors: Le Bourdonnec Bertrand , Meulon Emmanuelle , Yous Saïd , Houssin Raymond , Hénichart Jean‐Pierre
Published: March 2009

N‐alkyl pyrazolidine‐3,5‐diones and tetrahydropyridazine‐3,6‐diones have been synthesized by a new method in a three‐step sequence from dialkyl malonates or succinates respectively.
Ring transformations of heterocyclic compounds. XIX. Spiro[dihydropyridine‐indolines] novel heterocycles with two spiro‐condensed N‐containing subunits easy accessible by 1,3‐oxazinium ring transformation
Authors: Zimmermann Thomas , Abram Ulrich
Published: March 2009

The synthesis of hitherto unknown 1‐benzoyl‐1′,3′,3′‐trimethyl‐4,6‐diphenylspiro[1,2‐dihydropyridine‐2,2′‐indolines] 5 from 2,4,6‐triphenyl‐1,3‐oxazinium tetrafluoroborate (1b) and 1,3,3‐trimethyl‐2‐methyleneindolines 2 (used as such or generated in situ from the corresponding 3H‐indolium salts 4) in the presence of triethylamine in anhydrous acetonitrile by a 3,6‐[C3N+C2] 1,3‐oxazinium ring transformation is reported. Structure elucidation is performed by an X‐ray structure determination of the spiro[dihydropyridine‐indoline] 5a. Spectroscopic data of the transformation products and their mode of formation are discussed.
Quinolone analogues 2. A facile synthesis of novel 3‐substituted 1‐alkyl‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Sakurai Kazunori , Kajiwara Shinnosuke , Harada Kazuho , Okamoto Yoshihisa , Kim Ho Sik
Published: March 2009

The reaction of the 2‐(1‐alkylhydrazino)‐6‐chloroquinoxaline 4‐oxides 1a,b with diethyl acetone‐dicarboxylate or 1,3‐cyclohexanedione gave ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐1,5‐dihydropyridazino[3,4‐b]quinoxaline‐3‐carboxylates 5a,b or 6‐alkyl‐10‐chloro‐1‐oxo‐1,2,3,4,6,12‐hexahydroquinoxalino[2,3‐c]cinnolines 7a,b, respectively. Oxidation of compounds 5a,b with nitrous acid afforded the ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐4‐hydroxy‐1,4‐dihydropyridazino‐[3,4‐b]quinoxaline‐4‐carboxylates 9a,b, whose reaction with base provided the ethyl 2‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)acetates 6a,b, respectively. On the other hand, oxidation of compounds 7a,b with N‐bromosuccinimide/water furnished the 4‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)butyric acids 8a,b, respectively. The reaction of compound 8a with hydroxylamine gave 4‐(7‐chloro‐4‐hydroxyimino‐1‐methyl‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)‐butyric acid 12.
Research on heterocyclic compounds. XLII. The vilsmeier reaction in the synthesis of imidazo[1,2‐a]pyrimidine derivatives
Authors: Laneri Sonia , Sacchi Antonia , Abignente Enrico
Published: March 2009

The Vilsmeier reaction on imidazo[1,2‐a]pyrimidine ring is reported. The 3‐formyl derivative obtained is oxidized to yield the corresponding carboxylic acid.
Synthesis and structural analysis of (E)‐2‐(2′‐nitrovinyl)indoles from the corresponding 2‐formylindole derivatives
Authors: Rodriguez J. Gonzalo , Lafuente Antonio , Garcïa‐Almaraz Pablo
Published: March 2009

Preparation of 2‐formylindoles was carried out from the appropriate methylindole by oxidation with selenium dioxide and by Vilsmeier formylation. The 2‐(2′‐nitrovinyl)indoles have been obtained by condensa tion of 2‐formylindoles with nitroalkanes in the presence of ammonium chloride in good yields. In this reac tion, only the (E)‐isomer of the 2‐(2′‐nitrovinyl)indoles was observed by1H nmr and NOE experiments. Evidence for an extended conjugation through the double bond and the nitro group can be evaluate by the deshielding effect on the olefinic protons. Moreover, the non‐Beer's law behaviour in the uv‐visible spectra suggest the existence of some sort of complex for these compounds.
Ruthenium‐Catalyzed synthesis of quinolines from anilines and N‐allylic compounds by cascade amine exchange reaction‐heteroannulation
Authors: Cho Chan Sik , Ho Oh Byoung , Shim Sang Chul , Oh Dae Hee
Published: March 2009

Anilines react with N‐allylic compounds such as triallylamine and N,N‐diallylaniline in dioxane in the presence of a catalytic amount of ruthenium(III) chloride hydrate and bis(diphenylphosphino)methane and tin(II) chloride dihydrate to afford the corresponding quinolines in high yields. Several other phosphorus ligands are also effective, but bis(diphenylphosphino)methane is the ligand of choice. A reaction pathway involving cascade amine exchange reaction‐heteroannulation is proposed for this catalytic process.
Synthesis of cyanine dyes derived from benzotellurazo‐15‐crown‐5
Authors: Ke Weijun , Luo Xuehong , Liu Xiufang , Xu Hansheng
Published: March 2009

A series of crown ether cyanine dyes including crown ether styryl cyanine dyes, crown ether merocyanine dyes and crown ether squarylium cyanine dyes (unsymmetric and symmetric) derived from key intermediate 2‐methyl‐5,6(15‐crown‐5)benzotellurazole (1) were prepared.
Synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones
Authors: Coppola Gary M.
Published: March 2009

The present review covers the synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones which include oxygen, sulfur and nitrogen substituents. Literature coverage includes publications primarily from the mid 1960's to December 1999.
1H‐4,5,6,7‐tetrahydro‐1,3‐diazepines. Part I: Synthesis, spectral and chemical properties of 1,2‐diaryl derivatives
Authors: Hedrera Mónica E. , Perillo Isabel A.
Published: March 2009

The synthesis of several 1,2‐diaryl‐1H‐4,5,6,7‐tetrahydro‐1,3‐diazepines 1 by cyclization of N‐aryl‐N'‐benzoyltetramethylenediamines 2 is described. Two alternative synthetic routes to obtain precursors 2 are discussed, being that which employes pyrrolidine as starting material the most convenient. Nucleophilic attack of compounds 1 on methyl iodide affords 1,2‐diaryl‐1H‐4,5,6,7‐tetrahydro‐1,3‐diazepinium iodides 3. 1H‐nmr spectra of these compounds are unequivocally assigned by means of NOESY experiments, 1H‐nmr spectra of compounds 1 and 3 are analyzed and compared inter se and with those of compounds 1 run in the presence of trifluoroacetic acid‐d. Reduction of compounds 1 with borane leads regiospecifically to N‐aralkyl‐N'‐aryltetramethylenediamines 7.
New 2‐methylisothiazolones
Authors: Nádel Ágnes , Pálinkás János
Published: March 2009

New N,N'‐bis(alkoxycarbonyl)‐L‐cystine bis(methylamides) 4a, 4b and N,N'‐bis(benzyloxycarbonyl)‐L‐cystine bis(methylamide) 4c have been synthesized by mixed anhydride method from the essential amino acid L‐cystine 1 in good yield. These cystine bis(methylamides) 4a,b,c have been cyclized with sulfuryl chloride. New 2‐methyl‐4‐amino‐3‐isothiazolone and 5‐chloro‐2‐methyl‐4‐amino‐3‐isothiazolone hydrobromide salts 7, 8 have been obtained by deacylation of 2‐methyl‐4‐(benzyloxycarbonyl)amino‐3‐isothiazolone 5c and 5‐chloro‐2‐methyl‐4‐(benzyloxycarbonyl)amino‐3‐isothiazolone 6c with hydrogen bromide in acetic acid. The microbicidal effect of the new 2‐methy]‐3‐isothiazolones 5a,b,c; 6a,b,c; 7 and 8 compounds obtained by the above method has been investigated.
Synthesis of analogs of the ergot alkaloids
Authors: Strekowski Lucjan , Van Aken Koen , Gulevich Yuri
Published: March 2009

A number of 3,4,5,6‐tetrahydro‐1H‐azepino[5,4,3‐cd]indole derivatives have been synthesized starting with methyl indole‐4‐carboxylate functionalized at the 3 position.
Synthesis of 5‐N‐glycosylaminopyrimidines. A new class of compounds with potential anti‐aids activity
Authors: López M. D. , Quijano M. L. , Sánchez A. , Nogueras M.
Published: March 2009

Reactions between 5,6‐diaminopyrimidines 1a‐c and pentoses 2a‐e yield 5‐N‐glycosylaminopyrirnidines or 7‐polyhydroxyalkylpteridines, depending on the presence or absence of acetic acid. The “in vitro” anti‐HIV activity of 6‐amino‐2‐methoxy‐3‐methyl‐5‐N‐D‐ribosylaminopyrimidin‐4(3H)‐one 3e, 6‐amino‐2‐methoxy‐3‐methyl‐5‐N‐β‐D‐xylopyranosylaminopyrimidin‐4(3H‐one 3f, and 6‐amino‐2‐methylthio‐5‐N‐β‐L‐xylopyranosylminopyrimidin‐4(3H)‐one 3k, appears to be promising.
Synthesis of tricyclic triazepinones related to nevirapine
Authors: Castellano Sabrina , Stefancich Giorgio , La Colla Paolo , Musiu Chiara
Published: March 2009

Two novel tricyclic triazepinones structurally related to the reverse transcriptase inhibitor nevirapine were prepared from N‐(2‐nitrophenyl)‐ and N‐(3‐nitro‐2‐pyridinyl)‐1H‐pyrrol‐1‐amine. The synthetic sequence includes alkylation, reduction of the nitro group, triphosgene reaction followed by intramolecular cyclization. Activity of the two compounds against the HIV‐1 multiplication in acutely infected cells is also reported.
Facile access to 6‐substituted 1,4,5,7‐tetrahydropyrrolo[3,4‐b]‐pyridines via hantzsch type dimethyl 4‐aryl‐2‐formyl‐6‐methyl‐1,4‐dihydropyridine‐3,5‐dicarboxylates
Authors: Chudík Milostav , Marchalín Štefan , Knesl Peter , Daich Adam , Decroix Bernard
Published: March 2009

Efficient assembly of 6‐substituted 4‐aryl‐5‐oxo‐1,4,5,7‐tetrahydropyrrolo[3,4‐b]pyridines (7a‐f) is described according to a Hantzsch type reaction from formyl‐ester 4 by imination, borohydride reduction and intramolecular thermal amino‐ester cyclization. The starting compound 4 was prepared in three steps from the readily available formyl derivative 1, methyl 4,4‐dimethoxy‐3‐oxobutanoate and methyl 3‐aminocrotonate.
Heteroelectrocyclic reaction of 4‐azido‐3‐hydrazonoalkyl‐quinolines to 2‐arylaminopyrazolo[4,3‐c]quinolones
Authors: Hojas Gerhard , Fiala Werner , Stadlbauer Wolfgang
Published: March 2009

4‐Azido‐3‐acylquinolones 4 obtained from 4‐hydroxy derivatives 1 via tosylates 3 or chlorides 5, reacted with arylhydrazines 6 to generate 4‐azido‐3‐hydrazonoalkylquinolines 7. Thermolysis of 7 gave ring closure products which were assigned to 2‐arylaminopyrazolo[4,3‐c]quinolones 10. The thermal decomposition conditions of the azides 4 and 7 were studied by differential scanning calorimetry (DSC).
A facile synthesis of 3H‐indolium perchlorates by one‐pot hydrazone formation/fischer indolization
Authors: Zimmermann Thomas
Published: March 2009

N‐Substituted N‐phenylhydrazines 1, α‐branched ketones 2 and perchloric acid react in boiling ethanol to give via the in situ formed hydrazones 3 1,2,3,3‐tetrasubstituted 3H‐indolium perchlorates 4. The scope and limitations of this facile synthesis of 3H‐indolium derivatives which combines the hydrazone formation and the Fischer indolization to an one‐pot procedure are discussed.
Synthesis of nitrogen‐containing heterocycles 9. Preparation and carbon‐carbon bond cleavage of spiro[cycloalkane[1′,2′,4′]‐triazolo[1′,5′‐a][1′,3′,5′]triazine] derivatives and related compounds
Authors: Miyamoto Yoshiko
Published: March 2009

Diaminomethylenehydrazones of cyclic ketones 1–5 reacted with ethyl N‐cyanoimidate (I) at room temperature or with bis(methylthio)methylenecyanamide (II) under brief heating to give directly the corresponding spiro[cycloalkane[1′,2′,4′]triazolo[1′,5′,‐a][1′,3′‐5′]triazine] derivatives 7–12 in moderate to high yields. Ring‐opening reaction of the spiro[cycloalkanetriazolotriazine] derivatives occurred at the cycloalkane moiety upon heating in solution to give 2‐alkyl‐5‐amino[1,2,4]triazolotriazines 13–16. Diaminomethylenehydrazones 17–19, of hindered acyclic ketones, gave 2‐methyl‐7‐methylthio[1,2,4]‐triazolo[1,5‐a][1,3,5]triazines 21–23 by the reaction with II as the main products with apparent loss of 2‐methylpropane from the potential precursor, 2‐tert‐butyl‐2‐methyl‐7‐methylthio[1,2,4]triazolo[1,5‐a]‐[1,3,5]triazines 20, in good yields. In general, bis(methylthio)methylenecyanamide II was found to be a favorable reagent to the one‐step synthesis of the spiro[cycloalkanetriazolotriazine] derivatives from the diaminomethylenehydrazones. The spectral data and structural assignments of the fused triazine products are discussed.
Methoxylation of 4,5‐Dichloro‐2‐methyl‐6‐nitropyridazin‐3‐one
Authors: Park Jung‐Won , Kim Jeum‐Jong , Kim Ho‐Kyun , Kang Young‐Jin , Lee Woo Song , Yoon Yong‐Jin
Published: March 2009

This paper presents the methoxylation of 4,5‐dichloro‐2‐methyl‐6‐nitropyridazin‐3‐one with potassium carbonate/methanol.
Synthesis of 4‐(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazolidine‐3,5‐dione derivatives through cyclic transformations of 3‐(2‐phenylcarbazoyl)‐2(3H)‐benzoxazolone derivatives
Authors: Chau François , Milcent René
Published: March 2009

Four 3‐(3‐benzylidene‐2‐phenylcarbazoyl)‐2(3H)‐benzoxazolone derivatives 3 have been synthesized from benzoxazolone derivatives 1 and benzaldehyde N‐chloroformylphenylhydrazone 2. By acid hydrolysis, these compounds yielded 3‐(2‐phenylcarbazoyl)‐2(3H)benzoxazolone derivatives 4 which were not isolated and were transformed via an intramolecular reaction into 4‐(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazolidine‐3,5‐dione derivatives 5 in a good yield. Attempts to cyclize these compounds by intramolecular elimination of water into tricyclic compounds 6 with various dehydrating agents were unsuccessful.