bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractBy 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

AbstractThe 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

AbstractMicrowave 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

AbstractA 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.
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

AbstractThe 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

AbstractChiral 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

Abstract5‐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

AbstractTetrahydro‐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

AbstractA 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

AbstractNevirapine (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.
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

AbstractType 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

AbstractThe 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

AbstractNovel 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

AbstractReaction 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThermal 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

AbstractThe 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

AbstractThe 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

AbstractN‐(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

AbstractHydrolysis 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

AbstractPorphyrin‐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

AbstractThe 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

AbstractThe 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

AbstractFerrocenyl 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

AbstractFor 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

AbstractIn 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

Abstract2‐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

AbstractA 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.