bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactions of furazano[3,4‐b]quinoxalines with phosphorus ylides and an unusual oxidative transformation of the transylidation product
Authors: Gallos John K. , Lianis Pygmalion S. , Nicolaides Demetrios N.
Published: March 2009

Reactions of furazano[3,4‐b]quinoxalines 1 with phosphorus ylides 2 afford the transylidation product 3 and/or 4,9‐dihydrofurazano[3,4‐b]quinoxalines 4. Oxidation of 3 with phenyliodide bis‐trifluoroacetate gave the fused furan derivative 13 in high yield.
The reaction of arylmagnesium bromides with N‐(ω‐bromoalkyl)phthalimides
Authors: Braun Loren L. , Xia Jing , Cooney Mark J. , Ahmed Mohammed K. , Isaacson Eugene I.
Published: March 2009

The reaction of the N‐(ω‐bromoalkyl)phthalimides, 1 and 2, with a series of arylmagnesium bromides in tetrahydrofuran yielded the corresponding oxazoloisoindoles 4a‐4h and oxazinoisoindoles 5a‐5f. At low temperatures, phenylmagnesium bromide, on treatment with 1 and 2, yielded the open‐chain alcohols, 7 and 8. With 3, phenylmagnesium bromide yielded the corresponding alcohol 9 under any conditions utilized.

In several cases, the products isolated from the reaction of 1 with arylmagnesium bromides were shown to depend on the order of addition, with monoarylated oxazoloisoindoles 4c and 4d being formed when the Grignard reagent was added to 1, and triarylated products 10a and 10b formed when the order of addition was reversed. A further triarylated product 10c was also obtained by the latter method.
Mass spectrometric intramolecular cyclization reactions of some 2‐N‐phenyliminoperhydro‐1,3‐oxazines
Authors: Vainiotalo Pirjo , Fülöp Ferenc , Bernáth GÁBor , Pihlaja Kalevi
Published: March 2009

Mass spectrometric fragmentation of four monocyclic and eight condensed skeleton 2‐N‐phenyliminoper‐hydro‐1,3‐oxazine derivatives have been characterized by metastable ion analysis, collision induced dissociation measurements, exact mass measurements and ion structural studies. Extensive rearrangement reactions, best characterized in terms of intramolecular cyclizations, took place. Namely, when R = H the N‐cyclization was almost exclusive whereas in cases where R > H steric reasons rendered the O‐cyclization more feasible. Part of the fragmentation of the R = H compounds seemed to occur via the amino form. On the other hand the methane chemical ionization spectra of cis‐ and trans‐anellated 5,6‐trimethylene‐2‐N‐phenyliminoperhydro‐1,3‐oxazines proved that at least some imino structure was present in the gas phase.
Dipolar cycloaddition reactions of organic azides with some acetylenic compounds
Authors: Abu‐Orabi Sultan T. , Atfah M. Adnan , Jibril Ibrahim , Mari'i Fakhri M. , Ali Amer Al‐Sheikh
Published: March 2009

Phenyl azide 1 and several substituted benzyl azides 2a‐o underwent 1,3‐dipolar cycloaddition reactions with dimethyl acetylenedicarboxylate 3, phenylacetylene 4 and ethyl propiolate 5 to afford the triazoles 6‐13. The reactions of these azides with ethyl propiolate were found to be completely regiospecific.
Transformations of isomeric naphthopyranones. The synthesis of substituted β‐naphthyl‐α,β‐dehydro‐α‐amino acid derivatives
Authors: Ornik Brina , Stanovnik Branko , Tišler Miha
Published: March 2009

The opening of the pyranone ring in 2H‐naphtho[1,2‐b]pyran‐2‐one derivative (1) and 3H‐naphtho[2,1‐b]‐pyran‐3‐one derivatives 8 and 20 with nucleophiles afforded 3‐(naphthyl‐1)‐ and 3‐(naphthyl‐2)propenoates (substituted β‐naphthyl‐α,β‐dehydro‐α‐amino acid derivatives) 7, 13, 14, 15, 24, and 35.
Synthesis of new proton‐ionizable crown ether compounds containing substituted lh‐pyridin‐4‐one subcyclic units
Authors: Huszthy Peter , Kertesz Julia , Bradshaw Jerald S. , Izatt Reed M. , Redd J. Ty
Published: March 2009

Five novel pyridono‐18‐crown‐6 (10‐14) and two new benzyloxy‐substituted pyridino‐18‐crown‐6 (15 and 16) ligands have been prepared. By the catalytic hydrogenative removal of the benzyl group from the benzyloxy moiety at position 4 of the pyridine ring of 15 and 16, pyridono‐18‐crown‐6 ethers 5 and 12 were obtained. These ligands were transformed to their 3,5‐dibromo (10 and 13) and 3,5‐dinitro derivatives (11 and 14) by treatment with bromine in methylene chloride and nitric acid in acetic anhydride, respectively. The latter proton‐ionizable crown ethers have pKavalues of about 7.5 for 10 and 13 and 4.5 for 11 and 14. Thus, they are good candidates for complexation and proton‐coupled transport of selected cations.
Synthesis and preliminary use of naphthyl quinazoline and isoquinoline oxazolines for asymmetric allylic oxidation
Authors: Andrus Merritt B. , Sekhar B. B. V. Soma
Published: March 2009

This paper is dedicated to Professor Jerald S. Bradshaw, undergraduate mentor of MBA, with warmth and gratitude for his encouragement and outstanding leadership.

Four new oxazoline ligands, 4‐naphthyl‐2‐phenylquinazoline 4 and 1‐naphthylisoquinoline 5 were made using Suzuki coupling, a Pictet‐Gams reaction, and S‐amino alcohol. Preliminary use as ligands for asymmetric copper catalyzed allylic oxidation with cyclohex‐ene and perester showed promise providing S‐cyclohexenyl benzoate product in moderate enantioselectivity (64%ee).
Metal binding studies with macrocyclic hexathioethers: Transition metal complexes of 22S6 and 20S6
Authors: Grant Gregory J. , Brandow Christopher G. , Bruce Chrystal Williams , Bryant Mark A. , Kirk Rebecca M. , Lee Sabrina D. , Rickerd Kerry R. , Mehne Larry F.
Published: March 2009

The two macrocyclic hexathioethers, 1,4,7,12,15,18‐hexathiacyclodocosane (22S6) and 1,4,7,11,14,17‐hexathiacycloeicosane (20S6) have been examined with respect to their complexation behavior towards a variety of transition metals ions. In all of these complexes, the two ligands generate relatively strong ligand field, but their field strengths fall between the smaller ring and stronger field hexathioether ligands (such as 18S6) and larger ring and weaker field ligands, such as 24S6. The stability of the complexes towards hydrolysis parallels their reduced field strengths with first row transition metal complexes of both ligands showing enhanced sensitivity to solvolysis reactions compared to the analogous 18S6 complexes. In general, the electrochemical behavior of the hexathioether complexes shows metal centered oxidations which occur at higher potentials than those complexes involving trithioethers. We suggest that the hexathioether ligand is less able to expand and contract during the reduction and oxidation of the metal center. The complex [Pd(22S6)]2+ does not display the unusual spectroscopic and electrochemical properties observed in the analogous 18S6 complex.
Nucleic acid related compounds. 114. Synthesis of 2,6‐(disubstituted)purine 2′,3′‐dideoxynucleosides and selected cytotoxic, anti‐hepatitis b, and adenosine deaminase substrate activities
Authors: Robins Morris J. , Lindmark R. J. , Wnukt Stanislaw F. , Wilson John S. , Madej Danuta , Tyrrell D. Lorne J. , Gati Wendy P.
Published: March 2009

Selected 2,6‐(disubstituted)purine 2′,3′‐didehydro‐2′,3′‐dideoxynucleosides and 2′,3′‐dideoxynucleosides were prepared and evaluated. Treatment of 5′‐protected ribonucleosides with phenoxythiocarbonyl chloride and 4‐(dimethylamino)pyridine, or under Schotten‐Baumann conditions, gave high yields of 2′,3′‐O‐thiono‐carbonates that underwent Corey‐Winter elimination. Treatment of unprotected ribonucleosides with α‐ace‐toxyisobutyryl bromide in “moist” acetonitrile gave trans 2′,3′‐bromohydrin acetate mixtures that underwent reductive elimination with zinc‐copper couple or zinc/acetic acid. Catalytic hydrogenation of the resulting 2′,3′‐enes gave 2′,3′‐dideoxynucleosides. Treatment of the 2‐amino‐6‐chloropurine and 6‐amino‐2‐fluoro‐purine derivatives with nucleophiles gave 2,6‐(disubstituted)purine 2′,3′‐dideoxynucleosides. 2′,3′‐Dideoxyguanosine and the 2‐amino‐6‐[amino (16d), methoxy (16b), ethoxy (16c), and methylamino (16j)]purine 2′,3′‐dideoxynucleosides showed good anti‐hepatitis B activity with infected primary duck hepatocytes. Cytotoxic effects with selected analogues were evaluated in human T‐lymphoblastic and promyelocytic leukemia cell lines. The 2‐amino‐6‐fluoro derivative 16m was the most cytotoxic of the 2‐amino‐6‐(substituted)purine 2′,3′‐dideoxynucleosides, and 2‐fluoro‐2′,3′‐dideoxyadenosine (21a) was the most cytotoxic compound. The order of efficiency of hydrolysis of the 6‐substituent from 2‐amino‐6‐(sub‐stituted)purine 2′,3′‐dideoxynucleosides (Vmax/Km) with adenosine deaminase from calf intestine was: 2‐amino‐6‐[amino (16d) > methoxy (16b) > ethoxy (16c)], all of which were ≤3% of the efficiency with adenosine. The 6‐methylamino derivative 16j, as well as 16b, 16c, and 16d were readily converted into 2′,3′‐dideoxyguanosine by duck cell supernatants.
Synthesis of (S)‐3‐heteroaryl‐2‐hydroxy‐l‐propyl benzoates by ‘ring switching’ methodology
Authors: Mihelič Damjana , Jakše Renata , Svete Jurij , Stanovnik Branko , Grdadolnik Simona GoliČ
Published: March 2009

(S)‐5‐Benzoyloxymethyl‐3‐[(E)‐(dimethylamino)methylidene]tetrahydrofuran‐2‐one (6), prepared in 5 steps from L‐glutamic acid (1), was used as precursor in a one step ‘ring switching’ synthesis of (S)‐2‐hydroxy‐3‐heteroaryl‐l‐propyl benzoates 13‐18, 23, 24. In the reaction of 6 with 2‐aminopyridine (21) and 2‐amino‐4,6‐dimethylpyrimidine (22) the corresponding dimethylamine substitution products (25, 26) were obtained.
Synthesis of a novel ring‐expanded (“fat”) nucleotide analogue of phosphonomethoxyethylguanine (PMEG) containing the imidazo[4,5‐e][1,3]diazepine ring system
Authors: Chen Huan‐Ming , Hosmane Ramachandra S.
Published: March 2009

The synthesis of 6‐amino‐4,5‐dihydro‐8H‐1‐(2‐phosphonylmethoxyethyl)imidazo[4,5‐e][1,3]diazepine‐4,8‐dione (7), a novel ring‐expanded (“fat”) acyclic nucleotide analogue of phosphonomethoxyethylguanine (PMEG), has been reported. It was prepared in 4 steps in 51% overall yield starting from dimethyl imida‐zole‐4,5‐dicarboxylate.
Pseudo‐crown ether‐like structure by hydrogen‐bonded dimerization: A water complex with bis(2′‐hydroxyethyl) 2,6‐pyridinedicarboxylate in solid, solution, and gas phases
Authors: Habata Yoichi , Takeshita Makoto , Fukuda Yoji , Akabori Sadatoshi , Bradshaw Jerald S.
Published: March 2009

Dedicated to Professor Jerald S. Bradshaw Bis(2′‐hydroxyethyl) 2,6‐pyridinedicarboxylate (1) was prepared and the structure was characterized in solid (fourier transform‐ir and X‐ray analyses), in liquid (1H and 13C nmr titrations), and in the gas‐phase (fast atom bombardment (fab) and electron spray ionization (esi) ms). Two bis(2′‐hydroxyethyl) 2,6‐pyridinedicarboxylate molecules each with an included water molecule are bound together through hydrogen bonding to give a pseudo‐macrocycle in the solid state and in chloroform solution. The fab and esi mass spectra also suggested that ligand 1 forms a dimer in the gas‐phase.
On the reaction of 3,4‐dihydropyrimidones with nitric acid. Preparation and x‐ray structure analysis of a stable nitrolic acid
Authors: Puchala Agnieszka , Belaj Ferdinand , Kappe C. Oliver , Bergman Jan
Published: March 2009

A series of substituted 3,4‐dihydro‐2‐pyrimidones (DHPMs) was reacted with nitric acid under different reaction conditions. Treatment of DHPMs with 50‐65% nitric acid at 0 °C led to the formation of the corresponding dehydrogenated 2‐pyrimidones in moderate to good yields. In contrast, reaction of one representative DHPM with 60% nitric acid at 50 °C led to an unusually stable nitrolic acid, involving a formal nitration, nitrosation, and dehydrogenation step. The molecular structure of this product was determined by X‐ray crystallographic analysis
Free‐radical 4‐nitrophenylation of thieno[2,3‐b]pyridine. Part 3: Consideration of mechanistic and selectivity factors involved in the substitution process
Authors: Klemm Leroy H. , Reed Scott M.
Published: March 2009

A 1:1 geometrically oriented encounter complex between thieno[2,3‐b]pyridine (1) and 4‐nitrophenyldia‐zoacetate (2) is proposed to account for the dominant formation (ca. 64%) of the 2‐isomer in the mixture of 4‐nitrophenyl‐l isomers obtained previously. A mechanism involving one‐electron transfer from 1 to 2 plus fragmentation of 2· into 4‐nitrophenyl free radical, N2, and acetate ion is invoked. Formation of other isomers is discussed.

It is noted that there is a close correlation between orientational rules plus mechanisms of reaction for numerous free‐radical substitutions (SR) with SN reactions of alkyllithiums on furan, thiophene, N‐alkylpyrroles, pyridine, and their condensed aromatic molecules, including 1, as substrates. Also isomeric selectivities for SE, SN, and SR substitutions into 1 were shown to be qualitatively consistent with one another. While SE reactions occur largely at position 3 and then at 2, SN and SR reactions occur either at 2 or 6. Selectivity for positions 4 or 5 is small or zero.
Synthesis of diazadibenzo‐18‐crown‐6 ligands with appended chromophoric and fluorophoric groups as potential metal ion chemosensors
Authors: Xue Guo‐Ping , Savage Paul B. , Krakowiak Krzysztof E. , Izatt Reed M. , Bradshaw Jerald S.
Published: March 2009

Six new diazadibenzo‐18‐crown‐6 ligands substituted with two each of 8‐hydroxyquinoline (7), 8‐amino‐quinoline (attached through its C‐2 or C‐7 position) (12 and 13), 8‐methoxyquinoline (18), 5‐chloro‐8‐methoxyquinoline (19), and dansylamidoethyl (21) side arms were synthesized as potential metal ion chemosensors and potential reagents for the selective extraction of certain metal ions from aqueous solutions. Ligands 7, 12, 13, 18, and 19 were synthesized by reductive amination of diazadibenzo‐18‐crown‐6 (5) and the appropriate quinolinecarboxaldehydes. Bis(dansylamidoethyl)‐substituted ligand 21 was synthesized by treating diazacrown ether 5 with N‐dansylaziridine (20).
Synthesis of some isomeric quinoxaline derivatives with 6‐azauracil cycle
Authors: Wiedermannová Iveta , Slouka Jan
Published: March 2009

By diazotization of 3‐(2‐aminophenyl)‐1,2‐dihydroquinoxaline 1c, its 3‐(4‐aminophenyl)‐isomer2c, 3‐(2‐aminobenzyl)‐1,2‐dihydroquinoxaline‐2‐one 3c and its 3‐(4‐aminobenzyl)‐isomer 4c and by azo coupling of formed diazonium salts with ethyl cyanoacetylcarbamate, corresponding hydrazones ld‐4d were prepared. Cyclization of these compounds afforded compounds containing two heterocyclic rings with acidic N‐H groups in their molecules: 3‐[2‐(5‐cyano‐6‐azauracil‐1‐yl)‐phenyl]‐1,2‐dihydroquinoxaline‐2‐one 1e, its 4‐isomer 2e, 3‐[2‐(5‐cyano‐6‐azauracil‐1‐yl)‐benzyl]‐1,2‐dihydroquinoxaline‐2‐one 3e and its 4‐isomer 4e. The aminoderivative 1c was prepared by the reaction of N‐acetylisatine with o‐phenylenediamine and by hydrolysis of prepared N‐acetylderivative 1a. The aminoderivative 2c was prepared by the condensation of 4‐acetylaminophenylglyoxylic acid with o‐phenylenediamine and by hydrolysis of prepared N‐acetylderivative 2a. The aminoderivative 3c was prepared by the condensation of 2‐nitrophenylpyruvic acid with o‐phenylenediamine and by the reduction of the formed nitroderivative 3b and finally starting aminoderivative 4c was obtained by the condensation of o‐phenylenediamine with 4‐aminophenylpyruvic acid.
Synthesis and chemical reactivity of 3‐oxo‐2‐arylhydrazono‐propanenitriles
Authors: Abdallah Sanaa O. , Metwally Nadia H. , Anwar Hany F. , Elnagdi Mohamed H.
Published: March 2009

2‐Formyl‐2‐arylhydrazonoethanenitriles 6b‐d where prepared via reacting enaminonitrile 2b,c with aromatic diazonium salts. These reacted with phenylhydrazine to yield bis hydrazones that were converted to arylazopyr‐azoles via a novel Vilsmeier‐Haack reaction type. Reaction of 6c with hydroxylamine afforded oxime that could be successfully cyclised into arylazoisoxazole. Reaction of 6c with hydrazine hydrate to yield arylazoamino‐pyrazole that proved to be excellent precursors for synthesis functional substituted pyrazolopyrimidines.
Preparation of 1,3‐selenazoles using selenazadienes
Authors: Koketsu Mamoru , Imagawa Michie , Mio Takumi , Ishihara Hideharu
Published: March 2009

Reactions of selenazadienes with chloroacetonitrile yielded 1,3‐selenazol‐5‐carbonitriles in moderate to high yields. Reactions of the selenazadienes with chloroacetyl chloride and then with amines gave 1,3‐sele‐nazole‐5‐carboxamides.
Synthesis of 32‐phenyl‐substituted methyl E/Z‐pyropheophorbide‐a's from methyl E/Z‐pyropehophorbide‐a 131‐ketoximes
Authors: Wang Jin‐Jun , Imafuku Kimiaki , Shim Yong Key , Jiang Gui‐Ji
Published: March 2009

Methyl E/Z‐pyropheophorbide‐a 131‐ketoximes 2a,b and their O‐acetyl derivatives 3a,b were oxidized with osmium(VIII) oxide to give aldehydes 4a,b and 5a,b, respectively. The Wittig reactions of the aldehyde chlorines 4a,b and 5a,b with benzyltriphenylphosphonium chloride were performed to form the corresponding methyl (31E/Z,131E/Z)‐32‐phenylpyropheophorbide‐a 131‐ketoximes 6aa‐bb and their O‐acetyl derivatives 7aa‐bb; hydrolysis of these ketoximes 6aa,ba and 6ab,bb in formic acid produced methyl (E/Z)‐32‐phenylpyropheophorbide‐a's 8a,b.
Selective nucleophilic replacement of the benzylsulfanyl group in 2,4‐disulfanyl‐substituted thieno[2,3‐d]pyrimidin‐6‐carboxylic acid derivatives by secondary amines
Authors: Briel Detlef , Drescher Simon , Dobner Bodo
Published: March 2009

Thieno[2,3‐d]pyrimidines with benzylsulfanyl and allylsulfanyl group in the presence of other alkylsul‐fanyl substituents react selectively under mild conditions with secondary amines under replacement of the benzyl or allyl residue whereas the other substituents remain intact. This enables the synthesis of different basic substituted derivatives with potentially biologically activity.
Multinuclear NMR studies and ab initio structure calculations of hindered phencyclone diels‐alder adducts from symmetrical cyclic dienophiles: Cyclohexene, vinylene carbonate, vinylene trithiocarbonate and two N‐aryl maleimides
Authors: Callahan Ronald , Ramirez Orlando , Rosmarion Kerstin , Rothchild Robert , Bynum Kevin C.
Published: March 2009

A series of hindered Diels‐Alder adducts have been prepared from phencyclone, 1, with various unusual symmetrical cyclic dienophiles, including cyclohexene, 2a; vinylene carbonate, 2b; vinylene trithiocarbonate, 2c; and the N‐aryl maleimides: N‐(4‐dimethylamino‐3,5‐dinitrophenyl)maleimide (“Tuppy's maleimide”), 2d; and N‐[3,5‐bis(trifluoromethyl)phenyl]maleimide, 2e. The highly hindered adducts, 3a‐e, respectively, were extensively characterized by one‐ and two‐dimensional NMR methods, observing proton, carbon‐13 and fluorine‐19. High resolution COSY45 spectra permitted rigorous proton NMR assignments. The 2D heteronuclear C‐H chemical shift correlation spectra (HETCOR, XHCORR) were obtained for adducts 3a‐d, allowing specific assignments for protonated carbons. Corrections to earlier proton NMR assignments for the vinylene carbonate adduct are given; results of the gated decoupling 13C NMR experiment for this adduct supported endo adduct stereochemistry. Relative proton chemical shifts for bridgehead phenyls of adduct 3c appeared anomalous relative to other adducts, suggesting possible special anisotropic interactions (with endocyclic sulfur or other anisotropic groups in the product) due to the unusual calculated orientation of the phenyls. The unsubstituted bridgehead phenyls in all adducts were shown to exhibit slow exchange limit (SEL) 1H and 13C spectra on the NMR timescales at ambient temperatures (7 tesla) showing slow rotations about the C(sp3)‐C(aryl sp2) bonds. The rapid rotation of the N‐aryl rings of the maleimide adducts was indicated by fast exchange limit spectra, suggesting that ortho substitution of the N‐aryl ring may be necessary to slow this rotation to the SEL regime. Ab initio geometry optimizations at the Hartree‐Fock level were carried out for each adduct, with the 6‐31G* basis sets. Appreciable geometry differences were seen in calculated structures, and significant NMR chemical shift differences were experimentally observed, depending on the nature of the groups attached to the (Z)‐HC=CH moiety of the dienophiles.
Synthesis of new substituted 5‐methyl‐3,5‐diphenylimidazolidine‐2,4‐diones from substituted 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas
Authors: Sedlák Miloš , Keder Roman , Hanusek Jiří , Růzička Aleš
Published: March 2009

The reaction of substituted phenyl isocyanates with 2‐amino‐2‐phenylpropanenitrile and 2‐amino‐2‐(4‐nitrophenyl)propanenitrile has been used to prepare substituted 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas. In anhydrous phosphoric acid the first products to be formed from 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas are phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles, which on subsequent hydrolysis give the respective ureidocarboxylic acids. On prolongation of the reaction time, the phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles rearrange to give phosphates of 5‐methyl‐4‐imino‐3,5‐diphenylimidazolidin‐2‐ones, and these are subsequently hydrolysed to the respective substituted 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The ureidocarboxylic acids were also prepared by alkaline hydrolysis of 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones and ureidocarboxylic acids were characterised by their 1H and 13C NMR spectra. Structure of the 5‐methyl‐5‐(4‐nitrophenyl)‐3‐phenylimidazolidine‐2,4‐dione was verified by X‐ray diffraction. The alkaline hydrolysis of individual imidazolidine‐2,4‐diones was studies spectrophoto‐metrically in sodium hydroxide solutions at 25 °C. The rate‐limiting step of the base catalysed hydrolysis consists in decomposition of the tetrahedral intermediate. The reaction is faster if electron‐acceptor sub‐stituents are present in the 3‐phenyl group of imidazolidine‐2,4‐dione cycle. The pKa values of individual 5‐methyl‐3,5‐diphenylimidazolidine‐2,4‐diones have been determined kinetically.
Reaction of β‐cyano esters with hydrazine hydrate. Unexpected formation of dipyrrolo[1,2‐b:1′,2′‐e][1,2,4,5]tetrazine, a novel ring system
Authors: Wejroch Krystyna , Lange Jerzy , Wesołowska Aneta , Ski Tadeusz Jagodzi , Sadowska Maja , Karolak‐Wojciechowska Janina
Published: March 2009

Some intermediates and by‐products of the title reaction, known to yield 6‐hydrazinopyridazine‐3‐one derivatives, were isolated or detected when the amount of hydrazine hydrate used to react with two model β‐cyano esters was reduced to less than two equivalents. N'‐(1‐amino‐4‐hydrazino‐4‐oxo‐2‐phenylbutyli‐dene)‐4‐hydrazino‐4‐oxo‐2‐phenylbutanehydrazonamide and 3,3,8,8‐tetramethyl‐2,3,7,8‐tetrahydro‐1H,6H‐dipyrrolo[1,2‐b:1′,2′‐e][1,2,4,5]tetrazine‐1,6‐dione were isolated as the terminal products of side‐reactions; they were unreactive to hydrazine. The latter compound is a derivative of a novel ring system. Mechanism of the reaction was proposed.
Synthesis of meso‐tetra acid and ester functionalized calix[4]pyrroles
Authors: Akar Ahmet , Aydogan Abdullah
Published: March 2009

Novel meso‐tetracarboxylic acid and meso‐tetraester functionalized calix[4]pyrroles were synthesized by condensation of pyrrole with levulinic acid and ethyl pyruvate in sufficient yields. In addition, mixed condensation products can also be synthesized using this method. These new compounds may be useful as molecular receptors and polyfunctional starting materials for further derivatization.
Synthesis, characterization and biological activity of some 1,2,4‐triazine derivatives
Authors: El‐Barbary A. A. , Sakran M. A. , El‐Madani A. M. , Nielsen Claus
Published: March 2009

4‐Amino‐6‐methyl‐3‐(2H)‐thioxo‐5‐(4H)‐oxo‐1,2,4‐triazine (1) was condensed with 2‐methyl (or phenyl)‐4H‐3,1‐benzoxazin‐4‐one (5a,b) in boiling acetic acid to give compounds 8‐11. Reacting 1 with chloroacetyl chloride afforded the corresponding chloroacetamido and triazinothiadiazine derivatives 12 and 13. Condensing 2 with succinic anhydride and/or phthalic anhydride yielded compounds 14 and 15. Benzoylation of 4‐amino‐6‐methyl‐3‐(2H)‐thioxo‐5‐(4H)‐oxo‐2‐(2,3,4,5‐tetra‐O‐acetyl‐α‐D‐glucopyra‐nosyl)‐1,2,4‐triazine (19) afforded the corresponding 4‐N,N‐dibenzoyl derivative 20. Deblocking of the N‐2 glycoside 21 and the S‐glycoside 22 by methanolic ammonia gave compounds 23 and 24. Acetylation of 4‐amino glycoside 25a afforded the corresponding 4‐mono‐ and 4‐diacetyl derivatives 26 and 27. Deamination of 25a,b yielded compounds 28a,b. Methylation of compound 28b afforded the corresponding N4‐ and S‐methyl derivatives 29 and 30.
Synthesis of 2‐amino‐4,5‐dihydro‐3‐methanesulfonylfurans (and ‐thiophenes)
Authors: Yamagata Kenji , Okabe Fumi , Maruoka Hiroshi , Tagawa Yoshinobu
Published: March 2009

2‐Amino‐4,5‐dihydro‐3‐methanesulfonylfurans 7 and 2‐amino‐4,5‐dihydro‐3‐methanesulfonylthiophenes 8 were prepared by deamidation of tetrahydro‐2‐imino‐3‐methanesulfonyl‐3‐furancarboxamides 3 and of tetrahydro‐2‐imino‐3‐methanesulfonyl‐3‐thiophenecarboxamides 4 with bases. Compounds 3 and 4 were obtained by reaction of 2‐amino‐4,5‐dihydro‐3‐furancarboxamides 1 and 2‐amino‐4,5‐dihydro‐3‐thio‐phenecarboxamides 2 with methanesulfonyl chloride in the presence of triethylamine.
A facile one‐pot synthesis of novel substituted 1,2,3,4‐tetrahydropyrimidines Part 5 : Synthesis of bis[(l‐alkyl/aralkyl)‐5‐benzoyl‐6‐methylthio‐1,2,3,4‐tetrahydropyrimidinyl]alkane and benzene, bis[3‐phenyl‐7‐methyl‐4,5,6,7‐tetrahydropyrazolo[3,4‐d]‐pyrimidinyl]alkane and bis[1‐benzyl‐7‐phenyl‐1,2,3,4‐tetrahydro‐pyrazolo[1,5‐a]triazinyl]alkane and benzene
Authors: Dutta Milan Ch. , Chanda Kaushik , Vishwakarma Jai N. , Helissey Philippe
Published: March 2009

Bis‐1,2,3,4‐tetrahydropyrimidinylalkanes/benzenes 2a‐f have been synthesized by the reaction of N,S‐acetals with formaldehyde and diamines. Reaction of pyrazoles 3a and 3b with diamines and formaldehyde yield bis‐4,5,6,7‐tetrahydropyrazolo[3,4‐d]pyrimidinylalkanes 4a‐b and bis‐1,2,3,4‐tetrahydropyrazolo[1,5‐a]triazinylalkanes and benzene 5a‐c respectively in good yields.
Synthesis, characterization and spectral studies of various newer 4‐benzyloxy‐1H‐indole‐2‐carboxylic acid (arylidene)‐hydrazides
Authors: Jain Asheesh Kumar , Gupta Pradeep Kumar , Ganesan Kumaran , Pande Ambuja , Pardasani Deepak , Malhotra Ramesh Chandra
Published: March 2009

4‐Benzyloxyindole‐2‐carboxylic acid hydrazide reacts with aromatic and heterocyclic aldehydes in alcoholic medium in refluxing conditions to give 4‐benzyloxy‐1H‐indole‐2‐carboxylic acid (arylidene)‐hydrazides, important synthetic intermediates for the synthesis of a newer class of pharmacologically active compounds. We describe here the synthesis of various 4‐benzyloxy‐1H‐indole‐2‐carboxylic acid (arylidene)‐hydrazides by conventional as well as microwave irradiation techniques. The structures of these compounds have been confirmed by spectroscopic techniques (FTIR, NMR and MS). Some of the interesting features of the electron impact mass spectral fragmentation pattern of these compounds are also discussed.
Reaction of 1,3‐dicarbonyl compounds with o‐phenylenediamine or 3,3′‐diaminobenzidine in water or under solvent‐free conditions via microwave irradiation
Authors: Wang Zhong‐Xia , Qin Hua‐Li
Published: March 2009

Reaction of ophenylenediamine with β‐diketones or β‐ketoesters in water formed 2‐substituted benzimi‐dazoles. Reaction of 3,3′‐diaminobenzidine gave similar results. Under microwave irradiation conditions solvent‐free reaction of o‐phenylenediamine with β‐ketoesters afforded l,5‐benzodiazepin‐2‐one derivatives. An exception is the reaction of o‐phenylenediamine with ethyl acetoacetate under microwave irradiation, which gave 2‐methylbenzimidazole.
A microwave induced cyclisation of α‐phenylsulfonyl‐enaminoacrylates for the preparation of 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives
Authors: López Simón E. , Salazar José , Rebollo Oscar , Restrepo Jelem
Published: March 2009

Several 4‐aryl‐4H‐1,4‐benzothiazine 1,1‐dioxide derivatives have been prepared in good yields by microwave promoted cyclisation of α‐phenylsulfonyl‐enaminoacrylate intermediates in basic media. Benzothiazines were obtained without the use of a catalyst in short reaction times.
Syntheses ofN‐[3‐(1‐methyl‐1H‐2‐imidazolyl)propyl]benzamides andN‐[3‐(1‐methyl‐1H‐2‐imidazolyl)propyl]benzenesulfonamides
Authors: Shafiee A. , Shabani P. , Vosooghi M. , Foroumadi A.
Published: March 2009

A series of substitutedN‐(4‐substituted‐benzoyl)‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines (13) andN‐arylsulfonyl‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines (14) were prepared from the reaction of 3‐(1‐methyl‐1H‐imidazol‐2‐yl)propan‐1‐amine (7) with substituted benzoyl chloride or substituted‐benzene sulfonyl chloride respectively. Compound7was prepared by two independent methods.
A rapid and efficient method for the reduction of quinoxalines
Authors: McKinney Andrew M. , Jackson Kevin R. , Salvatore Ralph Nicholas , Savrides Elena‐Maria , Edattel Mary Jane , Gavin Terrence
Published: March 2009

Mono and di‐substituted alkyl and aryl quinoxalines are rapidly reduced in high yield to their respective 1,2,3,4‐tetrahydro‐derivatives by borane in THF solution. In the case of the 2,3‐di‐substituted compounds, reduction is stereoselective yielding exclusively the cis‐isomers. Sodium borohydride in acetic acid also reduces alkyl and aryl quinoxalines, but proceeds with lower yields and often produces side products. Sodium borohydride in ethanol reduces quinoxaline and 2‐methylquinoxaline in high yield; however, the reaction is very slow, whereas 2,3‐dialkyl and 2‐aryl quinoxalines are not efficiently reduced by sodium borohydride in ethanol.
New data about the reaction of benzyolacetonitrile with malononitrile and its self‐condensation
Authors: Abdelrazek Fathy M. , Michael Farid A.
Published: March 2009

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The reactions of benzoylacetonitrile with malononitrile in refluxing pyridine and its self condensation under fusion conditions in the presence of ammonium acetate and in refluxing pyridine were reinvestigated. New data were found and plausible mechanisms to account for the formation of the products are suggested.
Aziridines as templates: A general strategy for the stereospecific synthesis of 2‐azetidinones
Authors: Sharma S. D. , Kanwar Seema , Rajpoot Shivani
Published: March 2009

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Various routes to a variety of azridine‐2‐carboxylates have been described and the stereochemistry of these compounds has been determined by spectroscopic methods. Further, greater diversity of β‐lactams via ring expansion of these azridines‐2‐carboxylates were obtained by a general, efficient and direct stereospecific approach.
Cycloaddition reaction of schiff bases with ketenes generated by pyrolysis of 2‐aryl‐substituted 1,5,7‐trioxaspiro[2.5]octane‐4,8‐diones
Authors: Tsuno Takashi , Kondo Kosuke , Sugiyama Kunio
Published: March 2009

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The α‐oxo ketenes 6 which are generated by the pyrolysis of the 2‐aryl‐substituted 1,5,7‐trioxaspiro[2.5]octane‐4,8‐diones 1, were reacted with Schiff bases 2 to give spiro compounds constructed between the β‐lactam and 1,3‐dioxolan‐4‐one; i.e., the 2,3,6‐triaryl‐2‐aza‐5,7‐dioxaspiro[3.4]octane‐1,8‐diones 3 and 4. Hydrogenation of the mixture of 3a and 4a in the presence of catalytic amount of Pd‐C produced the trans‐2‐benzyloxy‐1,4‐diphenyl‐β‐lactam‐3‐carboxylic acid 9.
Amination of pyrido[3,2,1‐jk]carbazol‐6‐ones
Authors: Dang Hoai V. , Stadlbauer Wolfgang
Published: March 2009

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Amination of 4‐hydroxypyridocarbazolones 1 with aniline or benzylamine gave in good yields 4‐amines 3. With piperidine in a sealed tube from 4‐hydroxy‐ or 4‐chloro‐5‐alkylpyridocarbazolones 1 or 4 ring opened 1‐acylcarbazoles 5 were obtained. Only 4‐hydroxy‐5‐phenyl‐pyridocarbazolone 1d gave 4‐amines 6. Reduction of 4‐azidopyridocarbazolones 7 either by catalytic hydrogenation or in a 2‐step synthesis via phosphazenes 8 gave 4‐aminopyridocarbazolones 9. Amines 9 were also obtained from benzylamines 3 by catalytic debenzylation. A one step amination of 4‐hydroxy‐5‐phenylpyridocarbazolone 1d via debenzylation to 9d was observed by reaction with benzylammonium chloride. At elevated temperatures the highly fused 6,13b‐diazaindeno[1,2,3‐hi]chrysenone 10 was formed from 1d.
A facile KF/Al2O3 mediated method for the synthesis of substituted 3‐arylchromene‐2‐thiones
Authors: Xu Xiaowei , Hu Yongzhou
Published: March 2009

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A convenient and efficient method for the preparation of 3‐aryl‐chromene‐2‐thiones was reported. These compounds 2a‐2o with various functional groups were synthesized in high yield by a KF/Al2O3 meditated reaction of deoxybenzoins with CS2 under mild conditions.
Synthesis of novel 2‐aminoimidazo[4,5‐b]pyridines, including the thieno analogue of the cooked‐food mutagen IFP
Authors: Björk Malin , Grivas Spiros
Published: March 2009

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Eight new compounds, including three new ring systems obtained via the Friedländer condensation of ortho‐aminothiophenecarbaldehydes 11, 21 and 24 with creatinine (8), are reported. The condensation afforded 1, which is the thieno analogue of the cooked‐food mutagen IFP (2‐amino‐1,6‐dimethylfuro[2,3‐e]imidazo[4,5‐b]pyridine), and the benzothieno[2,3‐e]‐ and benzothieno[3,2‐e]imidazo[4,5‐b]pyridines 2 and 3. Attempts to condense 11 with isocreatinine (12) were unsuccesful. Desulfurization of 3 gave the known cooked‐food carcinogen PhIP. The 2‐nitro (4) and 2‐hydroxy (5) derivatives of 3 are reported. The related 2‐amino‐1‐methyl‐imidazo[4,5‐b]benzothiophene (25) was synthesized by a different route. Fully assigned 1H and 13C nmr data of all new compounds are reported.
Synthesis of 1‐substituted 3,5‐diaryl‐2‐pyrazolines by the reaction of α,β‐unsaturated ketones with hydrazines
Authors: Lévai Albert , Jekö József
Published: March 2009

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1‐Acetyl‐, 1‐propionyl‐ and 1‐phenyl‐3,5‐diaryl‐2‐pyrazolines have been synthesized by the reaction of the appropriate α,β‐unsaturated ketones with hydrazine or phenylhydrazine in hot acetic acid or propionic acid. Structures of all new 2‐pyrazolines 16‐40 have been elucidated by microanalyses, 1H and 13C nmr spectroscopies.
The synthesis of substituted phenylpyrimidines via suzuki coupling reactions
Authors: Delia Thomas J. , Schomaker Jennifer M. , Kalinda Alvin S.
Published: March 2009

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This paper describes the mon‐, di‐, and triarylation of the pyrimidine ring. It is possible to introduce one or more aryl rings in generally good yields and in a specific order, namely first in position 4, second in position 6, followed by position 2. A study of solvent and catalyst requirements has also been conducted.
Synthesis of some new spiro naphtho[2,3‐d][1,3]dithiole‐4,9‐dione derivatives
Authors: El‐Shafie A. K. , Soliman A. M. , Sultan A. A. , Abd‐Alla E.
Published: March 2009

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2(1‐Acetyl‐2‐oxopropylidene)naphtho[2,3‐d][1,3]dithiole‐4,9‐dione 1 reacts with a variety of bidentates reagents to give some new functionally substituted spiro naphthodithiole‐4,9‐dione derivatives.
The synthesis of new azoniathiahelicenes
Authors: Sato Kiyoshi , Katayama Yuu , Yamagishi Takamichi , Arai Sadao
Published: March 2009

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Synthesis of new azonia derivatives of thia[6]helicene (1) and thia[7]helicene (2) is described. The Knoevenagel condensation of 2‐methylbenzothieno[3,2‐a]quinolizinium salt (8) with appropriate arylaldehydes yielded 2‐(arylvinyl)benzothieno[3,2‐a]quinolizinium salts (9 and 10), respectively. Photocyclization of 2‐styrylbenzothieno[3,2‐a]quinolizinium salt (8) gave 7a‐azonia‐5‐thia[6]helicene (1) in 63% yield. Similarly, 2‐[2‐(2‐naphthyl)vinyl]benzothieno[3,2‐a]quinolizinium salt (10) afforded 7a‐azonia‐5‐thia[7]helicene (2) in 56% yield. The complete and unambiguous assignment of their 1H‐ and 13C‐nmr spectra was performed by utilizing two‐dimensional nmr spectroscopic methods.
Aromatization of 1,4‐dihydropyridines in the presence of methanesulfonic acid/NaNO2/wet SiO2 under both heterogeneous and solvent free conditions
Authors: Niknam Khodabakhsh , Razavian Seyed Mehdi , Zolfigol Mohammah Ali , Mohammahpoor‐Baltork Iraj
Published: March 2009

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A combination of methanesulfonic acid and sodium nitrite in the presence of wet SiO2 was used as an effective oxidizing agent for the oxidation of 1,4‐dihydropyridines to the corresponding pyridine derivatives under mild and heterogeneous conditions in excellent yields.
Synthesis of 9‐[1‐benzyl‐5‐(alkylsulfonyl)‐1H‐2‐imidazolyl]perhydro‐1,8‐acridinediones
Authors: Hadizadeh F. , Mehri N.
Published: March 2009

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Tricyclic dihydropyridines like ZM244085 are potential KATP channel openers. In this study 3‐cyanophenyl ring of ZM244085 was replaced with imidazolyl ring. So, 9‐[1‐benzyl‐5‐(alkylsulfonyl)‐1H‐2‐imidazolyl]perhydro‐1,8‐acridinediones (5d‐f) were synthesized from 2‐alkylsulfonyl‐1‐benzyl‐5‐formylimidazole (4d‐f) and cyclohexane‐1,3‐dione according to classical Hantzch synthesis as potential potassium channel modulators.
Novel 3‐benzoyl‐2‐piperazinylquinoxaline derivatives as potential antitumor agents
Authors: Piras Sandra , Loriga Mario , Carta Antonio , Paglietti Giuseppe , Paola Costi M. , Ferrari Stefania
Published: March 2009

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A series of new benzoylquinoxaline derivatives (7‐26) was synthesized and evaluated for antitumor activity against a panel of 60 human cell lines at the NCI of Bethesda. Among the compounds which have passed the preliminary screening, compound 23 exhibited the best profile and growth inhibition activity at 100 ‐ 10 μM. The compounds were then tested towards a folate‐dependent enzymes bio‐library including Thymidylate synthases enzymes and human Dihydrofolate reductase at 10 μM. The most of compounds exhibited a moderate inhibitory activity towards all or some of the enzymes tested with detectable inhibition constants (Ki) values in the range of 0.6‐70 μM. Compounds 21, 23, 24 showed Ki in the range of 10‐38 μM against both hDHFR and hTS.
Synthesis of oxadiazoloquinoxaline, oxathiadiazoloquinoxaline and oxadiazolobenzothiazine derivatives
Authors: Fylaktakidou Konstantina C. , Litinas Konstantinos E. , Saragliadis Athanasios , Adamopoulos Spyros G. , Nicolaides Demetrios N.
Published: March 2009

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Bis‐amidoxime1reacts with phosgene, thiophosgene and thionylchloride to give the corresponding bisfused oxadiazolo‐ and oxathiadiazoloquinoxalines2, 4, 5along with the unexpected furazano‐derivative3, while monoamidoximes9, 13by treatment with ethyl chloroformate affords the oxadiazoloquinoxaline and the oxadiazolobenzothiazine derivatives14, 15along with the dicarboxylated product16.
A practical approach for spiro‐ and 5‐monoalkylated barbituric acids
Authors: Singh Palwinder , Paul Kamaldeep
Published: March 2009

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The single step reactions of N,N′‐ substituted/‐unsubstituted barbituric acids with various alkyl dihalides under phase transfer catalytic conditions using DMF‐K2CO3 (base), TBAHSO4 (catalyst) provide spirobarbituric acids in moderate to high yields. Irrespective of the existence of C5‐monoalkylated compounds in the enolic form (confirmed by the isolation of some of its analogues), the second alkylation predominantly takes place at C5. The underlying mechanism for the reaction is discussed. The 5,7‐dimethyl‐5,7‐diaza‐spiro[2.5]octane‐4,6,8‐trione undergoes ring opening with NaCN, PhSH, HS(CH2)2OH and Br2 to provide 5‐monoalkylated barbiturates which are otherwise difficult to prepare by the usual alkylation of barbituric acids.
Tautomerism, regioisomerism, and cyclization reactions of acridinyl thiosemicarbazides
Authors: Klika Karel D. , Balentová Eva , Pihlaja Kalevi , Bernát Juraj , Imrich Ján , Vavrušová Martina , Kleinpeter Erich , Koch Andreas
Published: March 2009

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The regioselectivities of methyl‐ and phenylhydrazine with acridin‐9‐yl isothiocyanate (thus yielding thiosemicarbazides with acridine substituted on the urea‐type side) were examined. Methylhydrazine regioselectivity was high with the α‐nitrogen atom overwhelmingly more nucleophilic than the β‐nitrogen atom; phenylhydrazine regioselectivity was poor but varied with the solvent and only in the case of ethanol was nucleophilic predominance of the α‐nitrogen atom pronounced. Of note, whilst both phenyl thiosemicarbazides were present in solution only as spiro forms, the methyl product was present as an equilibrium mixture of open‐chain and spiro thiosemicarbazides. Reactions on the NH2 blocked analogue of methyl acridin‐9‐ylthiosemicarbazide (1‐isopropylidene‐2‐methylthiosemicarbazide) were also examined. Interestingly, present in the starting material itself was a structural motif of novelty wherein a triazolethione represented the major species of an equilibrium between cyclic and open‐chain forms.
Anodic cyanation of 1‐arylpyrroles
Authors: Liu Wei , Ma Yuan , Zhao Yu‐Fen , Yin Ying‐Wu
Published: March 2009

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The electrooxidation of several 1‐arylpyrroles has been carried out in methanol containing sodium cyanide at a platinum anode in a divided cell. In all instances, replacement of a heteroaromatic hydrogen by a cyano group occurred. On the basis of electroanalytical results, the anodic cyanation of the title compounds could be designed an EC process. As a result of two‐electron oxidation, the corresponding pyrrole cyanides were obtained in yields ranging from 76‐85%. The advantages of electrochemistry synthesis of pyrrole cyanides are simple reaction condition, low cost and high purity products.
Synthesis and characterization of a series of 1,x‐bis‐(4‐oxo‐3,4‐dihydro‐1,2,3‐benzotriazin‐3‐yl)alkanes
Authors: Hunter Naomi , Vaughan Keith
Published: March 2009

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Reaction of isatoic anhydride with an alkanediamine in DMF solution under mild conditions affords excellent yields of the 1,x‐bis‐{(2‐aminobenzoyl‐)amino}alkanes (2a‐k), which have been characterized by IR and NMR spectroscopy, high resolution mass spectrometry and elemental analysis. Diazotization of the bis‐{(2‐aminobenzoyl‐)‐amino}alkanes in aqueous solution gives high yields of the 1,x‐bis‐(4‐oxo‐3,4‐dihydro‐1,2,3‐benzotriazin‐3‐yl)alkanes (1a‐k), whch have also been characterized by IR and NMR spectroscopy, high resolution mass spectrometry and elemental analysis. The alkanediamines employed are as follows: ethylene diamine, 1,3‐propanediamine, 1,2‐propanediamine, 2‐methyl‐1,2‐propanediamine, 2,2‐dimethyl‐1,3‐propanediamine, 2‐hydroxy‐1,3‐propanediamine, 1,4‐diaminobutane, 1,5‐diaminopentane, 1,3‐diaminopentane (DYTEK® EP diamine), 1,6‐diaminohexane and 1,7‐diaminoheptane. The alternative method of synthesis of the bis‐(4‐oxo‐3,4‐dihydro‐1,2,3‐benzotriazin‐3‐yl)alkanes (1) via the diazonium salt from methyl anthranilate was explored.
Synthesis Of 1,8‐dioxa‐dibenzo[e,h]azulenese
Authors: Pešić Dijana , Landek Ivana Ozimec , Merćaep Mladen , Mesića Milan
Published: March 2009

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A novel synthetic route to 2‐methyl‐1,8‐dioxa‐dibenzo[e,h]azulenes [1] via cyclisation of the corresponding 1,4‐dicarbonyl compound is described. 1,4‐Dicarbonyl compounds were synthesized by the alkylation reaction of the 11H‐dibenzo[b,f]oxepine‐10‐one while analogous alkylation of 11H‐dibenzo[b,f]thiepine‐10‐one resulted in formation of O‐alkylated products. Selective oxidation of 2‐methyl group afforded 1,8‐dioxa‐dibenzo[e,h]azulenes with formyl and hydroxymethyl functionality at C(2) position.
An efficient synthesis of benzo[b][1,8]naphthyridine‐3‐carboxylic methyl esters
Authors: Nithyadevi V. , Rajendran S. P.
Published: March 2009

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Methyl‐3‐(2‐chloroquinolin‐3‐yl)acrylates 5a‐i on reaction with methyl amine in acetonitrile yielded methyl‐3‐[2‐(methylamino)quinolin‐3‐yl]acrylates 6a‐i. When, these were followed by the reaction with the Vilsmeier reagent, they afforded methyl benzo[b][1,8]naphthyridin‐3‐carboxylate 7a‐i in good yields.
Cyclocondensation reactions of heterocyclic carbonyl compounds XII. The double course of cyclization of 3‐(2‐aminobenzyl)‐1,2‐dihydro‐quinoxaline‐2‐one
Authors: Fryšová Iveta , Slouka Jan , Hlaváč Jan , Lyčka Antonńan
Published: March 2009

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The cyclocondensation reaction of compound 1 in boiling hydrochloric acid had an unexpected course. Instead of supposed 5,11‐dihydro‐quinoxalino[2,3‐b]quinoline 6a, 2‐(indol‐2‐yl)‐benzimidazole 4 was isolated as the major product.
Ruthenium‐catalyzed biginelli condensation: A simple and efficient one‐pot synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones under mild reaction conditions
Authors: Jain Suman L. , Sharma Vishal B. , Sain Bir
Published: March 2009

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Ruthenium trichloride was found to be an efficient catalyst for the first time for the synthesis of a variety of 3,4‐dihydropyrimidin‐2(1H)‐ones by cyclocondensation of an aldehyde, β‐dicarbonyl compound and urea in excellent yields under mild reaction conditions.
One‐Pot stereoselective synthesis of trans‐4,5‐dialkoxy‐1,3‐bis (2‐pyrimidinyl)imidazolidines through a three‐component reaction
Authors: Ghandi Mehdi , Salimi Farshid , Olyaei Abolfazl
Published: March 2009

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Stoichiometric reaction of 2‐aminopyrimidine with formaldehyde in the presence of formic acid catalyst in water gave N,N′‐bis(2‐pyrimidinyl)methanediamine (5). Subsequent cyclocondensation of 5 with glyoxal in alcohol (MeOH, EtOH, PrOH and i‐PrOH) under reflux conditions led to the formation of the corresponding 4,5‐dialkoxy‐1,3‐bis(2‐pyrimidinyl)imidazolidines (6a‐d). 4,5‐Dihydroxy‐1,3‐bis(2‐pyrimidinyl) imidazolidine (6e) was obtained when the reaction was carried out in acetonitrile. Based on 1H NMR analysis, it was found that the trans‐dialkoxyimidazolidines (6) were selectively obtained in these cyclocondensation reactions.
A facile synthesis of 2‐substituted thieno[3′,2′‐5,6]‐pyrido[4,3‐d]pyrimidin‐4(3H)‐ones
Authors: Liu Jian‐Chao , He Hong‐Wu , Ren Qing‐Yun , Ding Ming‐Wu
Published: March 2009

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The thienopyridine derivative 2, obtained from reaction of acetoacetic ester with 1 in the presence of tin tetrachloride, was treated with triphenylphosphine in hexachloroethane and Et3N to give iminophosphorane 3. Iminophosphorane 3 reacted with phenyl isocyanate to give carbodiimide 4, which was further treated with phenols or ethenol to produce 2‐substituted 5,8,9‐trimethyl‐3‐phenyl‐thieno[3′,2′‐5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐ones 5 in presence of catalytic amount of K2CO3 or EtONa. The structures of compounds 5 were confirmed by 1H NMR, IR, MS, and elemental analysis.
Reaction of 4‐substituted thiosemicarbazides with (2,4,7‐trinitro‐9H‐fluoren‐9‐ylidene)propanedinitrile
Authors: Hassan Alaa A. , Ibrahim Yusria R. , Shawky Ahmed M. , Döpp Dietrich
Published: March 2009

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4‐Substituted thiosemicarbazides4a‐creacted with (2,4,7‐trinitro‐9H‐fluoren‐9‐ylidene)‐propanedinitrile (2) in pyridine with admission of air to form spiro[fluorene‐9,3′‐(1,2,4‐triazole)]derivatives5a‐cand (4‐substituted thiosemicarbazono)propanedinitriles6a‐cin modest yields. 2,4,7‐Trinitro‐9‐fluorenone (8) as well as one reduction product thereof and of2, namely compounds9and10, respectively are also found. A rationale for the conversions observed is presented.
Synthesis and biological activity of novel 1‐(2,3,4‐trimethoxyphenyl)‐2‐{[5‐(3,4,5‐trimethoxyphenyl)‐1,3,4‐thiadiazol‐2‐yl]thio}ethanone oxime ester derivatives
Authors: Xue Wei , Song Baoan , He Wei , Wang Hua , Yang Song , Jin Linhong , Hu Deyu , Liu Gang , Lu Ping
Published: March 2009

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In a search for new fungicide and anticancer agent with improved biological properties and different bioactivity spectrum, we designed and synthesized a series of novel oxime esters containing 1,3,4‐thiadiazole group in moderate yield starting from gallic acid. The title compounds were identified by IR, 1H NMR, 13C NMR and elemental analysis. The bioassay tests showed that these title compounds exhibit weak to moderate anticancer activity in vitro by MTT method.