bluuebunny/crossref_metadata_2025_split huggingface dataset:
The reaction of N‐carboalkoxy reissert analogs with carboxylic acids
Authors: Popp Frank D. , Duarte Frederick F. , Uff Barrie C. 
Published: April 2009

AbstractThe reaction of N‐carboalkoxy Reissert analogs in the presence of carboxylic acids yields the corresponding ester and heterocyclic base. Use of methoxy substituted benzoic acids yields, instead of the ester, the respective anhydride. Amides can also be prepared in a similar fashion.
Synthesis and hydrolysis of substituted imidazolinium salts. Behaviour of the degradation products on varying pH
Authors: Fernández Beatriz M. , Reverdito Ana M. , Paolucci Guillermo A. , Perillo Isabel A. 
Published: April 2009

AbstractReaction of l‐alkyl‐2,3‐diarylimidazolinium iodides 1a‐i with alkaline solutions afforded N'‐alkyl‐N‐aroyl‐N‐arylethylenediamines 2a‐i. Compounds 2 are stable under acid conditions but in neutral or alkaline media rearrange giving N‐alkyl‐N‐aroyl‐N‐arylethylenediamines 3a‐i. Treating compounds 3 with concentrated acids reverse reaction 3 → 2 takes place.Kinetic studies were performed on this intramolecular N → N' aroyl transfer over the Ho‐pH range −0.9 to 2.30. Compounds 3 undergo acyl transfer to give 2 by a mechanism which involves a change in the rate determining step from formation to catalysed decomposition of a heterocyclic intermediate I2+ on going from Ho to pH values. The existence of maxima in the pH rate profile allowed to determine apparent pKa values of the imidazolidine intermediates which gave good correlation with Hammett sigma values. Stability of these heterocycles was also predicted by determination of thermodynamic parameters.
Nouvelle méthode de synthèse de thiazolopyridines
Authors: Couture Axel , Grandclaudon Pierre , Huguerre Eric 
Published: April 2009

AbstractIl est démontré que la condensation de thioesters aromatiques et aliphatiques avec l'anion d'orthoaminochloropyridines diversement préparé constitue la meilleure stratégie d'accès vers des systèmes polyhétérocycliques condensés tels que les thiazolopyridines. La formation éventuelle de thioamides intermédiaires peut être complétée par une conversion chimique ou photochimique en produits de condensation désirés.
Kinetic study on the anelation of heterocycles. 1. Quinoxalinone derivatives synthesized by hinsberg reaction
Authors: Abasolo María I. , Gaozza Carlos H. , Fernández Beatriz M. 
Published: April 2009

AbstractKinetic studies on the Hinsberg condensation were performed trying to improve yields and achieve regio‐selectivity in the attainment of benzene‐substituted 3‐methylquinoxalin‐2(1H)‐ones. The course of the reactions between o‐phenylenediamine (o‐PDA) and substituted o‐PDA with pyruvic acid (2a) or ethyl pyruvate (2b) were followed by uv spectrophotometry at different pH values. The formation of 3‐methylquinoxalin‐2(1H)‐one (6a) was improved using sulphuric acid‐water mixtures, in which the reaction proceeded by a different mechanism. 3‐Methyl‐7‐methoxyquinoxalin‐2(1H)‐one (7b) was regioselectively synthesized independently of the pH of the reaction media. Reaction of 2‐amino‐4‐methylamine (1c) with 2a or 2b led to a mixture of 6 and 7‐quinoxalinone isomers, 6c and 7c, while 2‐amino‐4‐nitroaniline (1d) and 2,4‐diaminoaniline (1e) with 2a or 2b did not afford the heterocycle. In every case reactions with 2a were 100–1000 times faster than those with 2b. Mechanisms are proposed trying to account for the experimental results.
A 6‐bromocoumarin analog of chloramphenicol
Authors: Joshi Ramachandra V. , Badiger Virupax V. 
Published: April 2009

Abstractdl‐threo‐2‐Dichloroacetamidol‐1‐[3‐(6‐bromocoumarinyl)]propane‐1,3‐diol (7) was synthesized according to Sorm's method. The fragmentation of dichloroacetamidomethyl 3‐(6‐bromocoumarinyl)ketone (4) under electron impact is reported. The results of in vitro antibacterial screening of the newly synthesized compounds have been presented.
Synthesis of 4,7‐dihydro‐4‐oxoisoxazolo[5,4‐b]pyridine‐5‐carboxylic acid derivatives as potential antimicrobial agents
Authors: Chiarino D. , Napoletano M. , Sala A. 
Published: April 2009

AbstractSynthetic approaches to 3‐substituted‐7‐ethyl‐4,7‐dihydro‐4‐oxoisoxazolo[5,4‐b]pyridine‐5‐carboxylic acid derivatives from 3‐substituted‐5‐aminoisoxazoles are reported.
Flavonoids. 41. Stereospecific synthesis of 2,3‐dihydro‐c‐3‐substituted‐t‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐ones
Authors: Patonay Tamás , Patonay‐Péli Erzsébet , Litkei György , Szilágyi László , Batta Gyula , Dinya Zoltán 
Published: April 2009

AbstractThe synthesis of 2,3‐dihydro‐t‐3‐mesyloxy‐c‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐one (1) is described. The reaction of mesylate 1 with various nucleophiles, first of all O‐ and N‐nucleophiles, yields the corresponding 2,3‐dihydro‐c‐3‐substituted‐t‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐ones 2b, 7b, 9, 10, 12, 14 and 18. Azide 14 is a useful intermediate for the synthesis of flavonoids 15–17.
Correlation of the rates of solvolysis of the S‐Ethyldibenzothiophenium Ion
Authors: Kevill Dennis N. , Anderson Steven W. 
Published: April 2009

AbstractThe specific rates of solvolysis of S‐ethyldibenzothiophenium trifluoromethanesulfonate have been found to give a good linear correlation with the previously determined specific rates of solvolysis of the triethyloxonium ion, and hence with the solvent nucleophilicity scale established from the triethyloxonium ion study. A value for the sensitivity to changes in solvent nucleophilicity (1) of greater than unity (1.15) is in accord with reactivity‐selectivity considerations.
Aktive malonester als synthons für heterocyclen: Eine methode zur herstellung von 4‐hydroxy‐2(1H)‐pyridonen
Authors: Kappe Thomas , Ajili Samir , Stadlbauer Wolfgang 
Published: April 2009

Abstract4‐Hydroxy‐2(1H)‐pyridone 3 können in ausgezeichneten Ausbeuten aus den Azomethinen 1 mit Trichlorphenyl‐malonaten 2 hergestellt werden, wobei die Variation der Substituenten in 1‐, 3‐, 5‐ und 6‐Stellung in einem weiten Rahmen möglich ist. Auf diese Weise werden auch in 5,6‐Stellung überbrückte Pyridone 5, 7 synthetisiert. Weiters wird die Herstellung 1‐unsubstituierter Pyridone über die Entbenzylierung der 1‐Benzylpyridone 3a,b sowie die Halogenierung zu isomeren 2‐ bzw. 4‐Chlorpyridonen 8, 9 und dem Dichlorpyridin 10 beschrieben.
The synthesis of a series of (α‐amino)indol‐3‐yl ketones
Authors: Sanchez Joseph P. , Parcell Robert F. 
Published: April 2009

AbstractA series of [(α‐amino)indol‐3‐yl]‐2‐methyl‐1‐propanones and [(α‐amino)indol‐3‐yl]cyclopentylmethanones has been synthesized by a variety of reductive reactions performed on the corresponding series of (α‐azido)‐indol‐3‐yl ketones. One of the more interesting reductive procedures involved the palladium‐catalyzed decomposition of formic acid with the formation of hydrogen in situ. The (α‐azido)ketones were prepared in excellent yield by the displacement of the tertiary bromine atom from the (α‐bromo)ketones using sodium azide in N,N‐dimethylformamide. Bromination was accomplished by using either cupric bromide in ethyl acetate/chloroform or phenyltrimethylammonium tribromide in tetrahydrofuran.
An intramolecular cyclization of 7‐substituted 6‐fluoro‐ 1,8‐naphthyridine and ‐quinoline derivatives
Authors: Nishimura Yoshiro , Minamida Akira , Matsumoto Jun‐Ichi 
Published: April 2009

AbstractA synthesis of 1,4‐oxazine and pyrazine ring systems by an intramolecular cyclization of 7‐substituted 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine and ‐quinoline derivatives having a nitrogen or oxygen nucleophilic site in the C‐7 appendage was studied. The in vitro antibacterial activities of compounds prepared by this method were tested.
Synthesis of 3,4‐Dihydro‐2‐methyl‐3‐oxo‐N‐aryl‐2H‐[1]benzothieno[3,2‐e1,2‐thiazine‐4‐carboxamide 1,1‐Dioxides
Authors: Marfat A. , Chambers R. J. 
Published: April 2009

AbstractA novel synthesis of the title compounds, representing a new heterocyclic ring system, is described. Chlorosulphonation of 3‐methylbenzo[b]thiophene followed by reaction with methylamine gave sulfonamide, 4. Lithiation of 4, followed by quenching with carbon dioxide yielded acetic acid, 5. Cyclodehydration of 5 to benzothienothiazine 6 followed by reaction with aryl isocyanates afforded the desired benzothieno[3,2‐e]‐1,2‐thiazine‐4‐carboxamides 1a‐f.
Sur le mécanisme de la réaction de meth‐cohn‐tarnowski de préparation des thiocoumarines
Authors: El‐Ahmad Youssef , Reynaud Pierre 
Published: April 2009

AbstractLa mise en oeuvre du t‐butylthio‐2 benzaldéhyde et la cyclisation par chauffage dans l'acide polyphosphorique des (t‐butylthio‐2 phényl)‐3 cyano‐2 acrylamides conduit intermédiairement aux carboxamido‐3 imino‐2 2H‐(benzo[b]thiopyranne‐1), hydrolysables en thiocoumarines. Les auteurs suggèrent la formation intermédiaire d'un ion thiophénate prenant naissance par un mécanisme électronique à six centres.
Synthesis of 1,4,5‐trisubstituted imidazoles as juvenile hormone analogues
Authors: Bernasconi Silvana , Jommi Giancarlo , Pagliarin Roberto , Tavecchia Paolo 
Published: April 2009

AbstractEight compounds containing N‐ or N′‐alkylated imidazole rings have been synthesized and their structures have been chemically and spectroscopically demonstrated. These molecules, submitted to biological tests in order to evaluate their activity as juvenile hormones, provoke morphological changes in the pupae of Tenebrio Molitor.
Macrocyclic polyether‐diester compounds as phase‐transfer catalysts
Authors: Anchisi Carlo , Corda Luciana , Fadda Anna Maria , Maccioni Anna Maria , Podda Gianni 
Published: April 2009

AbstractThree new macrocyclic polyether‐diester have been prepared. The catalytic activity of these compounds has been tested in the Br/I exchange reactions of octyl bromide with different ionic diameter cations.
Synthesis and physicochemical studies on 1,2‐bisazolylethanes
Authors: Torres J. , Lavandera J. L. , Cabildo P. , Claramunt R. M. , Elguero J. 
Published: April 2009

AbstractTwenty symmetrical and asymmetrical 1,2‐bisazolylethanes have been obtained from azoles and 1,2‐dibromoethane or 1‐chloro‐2‐(pyrazol‐1‐yl)ethane by phase transfer catalysis (PTC). The 1H and 13C nmr properties are reported and the chemical shifts of the ethylene carbon atoms discussed using an additive model.
A facile synthesis of [1,2,4]triazino[3,2‐f]purines and [1,2,4]triazepino[3,2‐f]purines
Authors: Ueda Taisei , Adachi Tsuneyasu , Nagai Shin‐Ichi , Sakakibara Jinsaku , Murata Mitsuo 
Published: April 2009

Abstract[1,2,4]Triazino[3,2‐f]purines 3a‐e and [1,2,4]triazepino[3,2‐f]purine 5 were synthesized by the reaction of 7,8‐diamino‐1,3‐dimethylxanthine 1 with diketones such as glyoxal, diacetyl, dibenzoyl, pyruvic aldehyde dimethyl acetal, phenylglyoxal or acetylacetone in acetic acid in the presence of boric acid or polyphosphoric acid.
Reactions of 1,3‐thiazine‐2,6‐dithiones. Part 7. Formation reactions of 3‐thioureidocinnamthioamides, 3‐[bis(alkylthio)methyleneamino]‐ and 3‐[bis(alkoxy)methyleneamino]‐dithiocinnamic acid esters by the thiazine ring opening reactions with primary amines, thiols, and alcohols. Recyclizing reactions of the acyclic thioamides and the alkyl dithiocinnamates and some related compounds
Authors: Yamamoto Tatsuo , Muraoka Motomu 
Published: April 2009

Abstract2‐Alkylamino‐ and 2‐arylamino‐1,3‐thiazine‐6‐thiones 3 were synthesized by the reactions of 1,3‐thiazine‐2,6‐dithiones 1 or 2‐methylthio‐1,3‐thiazine‐6‐thiones 2 with aliphatic or aromatic primary amines. 3‐(3‐Alkyl‐thioureido)cinnamthioamides 4 were formed on treatment of compounds 3 with primary amines. The same compounds 4 formed pyrimidine‐2,4‐dithiones 5 and primary amines by acid‐catalyzed intramolecular cyclization and the primary amines and compounds 5 gave compounds 4 quantitatively (vice versa). Further, treatment of compounds 4 (R3 = butyl, pentyl, hexyl) with hydrochloric acid or thermolysis of 4 gave rise to 2‐alkylimino‐6‐amino‐1,3‐thiazine‐5‐(N‐alkyl)carbothioamides 6 accompanied by compounds 5. Compounds 3, when allowed to react with the amines in aqueous ethanol gave 3‐alkyl‐2‐alkylaminopyrimidine‐6‐thiones 8 in addition to compounds 4 by two types of reactions occuring simultaneously.On the other hand, compounds 2, when treated with thiols and alcohols instead of primary amines in the presence of alkyl iodide, yielded alkyl 3‐[bis(alkylthio)methyleneamino]dithiocinnamates 11 and alkyl 3‐[bis(methoxy)methyleneamino]dithiocinnamates 14 respectively.The mechanisms of the formation of these cyclic and acyclic compounds here obtained are also discussed in some detail.
Reaction between o‐diamino‐1,2,6‐thiadiazine 1,1‐dioxides and aldehydes to give fused imidazo and pyrazino derivatives
Authors: Herrero Angela , Ochoa Carmen 
Published: April 2009

AbstractReaction between 3,4,5‐triamino‐1,2,6‐thiadiazine 1,1‐dioxides and aldehydes, in acetic acid or DMF, under anhydrous conditions, leads to a mixture of imidazo[4,5‐c]‐ and pyrazino[2,3‐c]‐1,2,6‐thiadiazine derivatives. The ratio of both compounds depends on the nature of the aldehydes used. The same reaction, in the absence of solvent, affords, only pyrazinothiadiazine derivatives. The uv, 1H‐ and 13C‐nmr data of the new compounds are reported.
Reactions of electron‐rich heterocycles with orthocarboxylic acid derivatives. 11. Reactions of carbazole and 4‐methoxycarbazole with triethyl orthoformate: Regiospecific functionalization of the carbazole nucleus
Authors: Witzel H. , Pindur U. 
Published: April 2009

AbstractCarbazole (1a) and 4‐methoxycarbazole (1b) can be regioselectively functionalized by reaction with triethyl orthoformate. Whereas the reaction of 1a with the ortho ester furnishes the amide acetal 2, the new carbazole derivatives 4–10 are formed, depending on the reaction conditions, in the electrophilic substitution of 1b. The products of this reaction sequence provide a contribution to studies on the mechanism of the transformation of 1b to tris‐carbazolylmethane 5. Compound 5 represents a new, three‐bladed propeller in the triheteroarylmethane series.
Heterocyclic photorearrangements. Photochemical behaviour of some 3,5‐disubstituted 1,2,4‐oxadiazoles in methanol at 254 nm
Authors: Buscemi Silvestre , Cicero Maria G. , Vivona Nicolò , Caronna Tullio 
Published: April 2009

AbstractPhotochemical behaviour of some 3,5‐disubstituted 1,2,4‐oxadiazoles in methanol at 254 nm has been investigated. Ring photoisomerization to the 1,3,4‐oxadiazole heterocycle or formation of open chain compounds involving the nucleophilic solvent was shown to depend on the nature and the position of the substituent. Photoinduced ring closure into the benzimidazole system, involving a 3‐N‐phenylamino side chain sequence and a photolytic intermediate of the oxadiazole heterocycle, is also reported.
A new synthesis of 1‐aryl‐5‐cyano‐1H‐pyrazole‐4‐carboxylic acid, ethyl esters
Authors: Beck James R. , Ackmann Stephen A. , Staszak Michael A. , Wright Fred L. 
Published: April 2009

AbstractA novel conversion of 5‐amino‐1‐aryl‐1H‐pyrazole‐4‐carboxylic acid, ethyl esters to the corresponding 5‐cyano esters is described. The process involves nonaqueous diazotization of the amine to form the methyl thioether, which is oxidized to the methyl sulfone, which, in turn, is displaced by cyanide ion. The cyano esters are precursors to chemical hybridizing agents in wheat and barley.
Photochemistry of ommochromes and related compounds
Authors: Bolognese A. , Liberatore R. , Scherillo G. 
Published: April 2009

AbstractThe photochemistry of some synthetic ommochromes, the 1‐methoxy‐11‐(β‐aspartoyl‐acetyl‐methyl ester)‐5H‐pyrido[3,2‐a]phenoxazin‐5‐one (2), the 1‐methyl‐1‐(1′‐[1′[11‐(β‐aspartoyl‐methyl ester‐imino)]ethenyl)‐ketal‐1 H,5H‐pyrido[3,2‐a]phenoxazin‐5‐one (3) and the 1,5‐dimethoxy‐11‐(β‐aspartoyl‐N‐acetyl‐methyl ester)‐pyrido[3,2‐a]phenoxazine (4), obtained from the oxidation of the 3‐hydroxykynurenine (1), has been examined. In an acidic methanol solution of 2, a reversible solvent photoaddition was observed, associated with a yellow‐red bathochromic shift. The mixture, stored in the dark, quantitatively records the starting absorption spectrum. In an acidic enviroment, 3 and 4, affording 2, show the same photochemical behaviour. A plausible mechanism, for explanation of the process is suggested.
Products from furans. V Synthesis of oxygen containing isosteres of sympathomimetic amines via 6‐hydroxy‐2H‐pyran‐3(6H)‐ones and their cis‐platinum(II) complexes
Authors: Georgiadis Minas P. , Haroutounian Serkos A. , Bailar John C. 
Published: April 2009

AbstractNovel amino analogues of sympathomimetic amines, which contain the pyran ring as a consequence of their common route of preparation, were synthesized. A modified Strecker reaction on tetrahydro‐2H‐pyran‐3‐one derivatives yielded α‐benzylamino nitriles, which upon subsequent hydrogenation and hydrogenolysis gave the target 1,2‐diamines. The prepared diamines were indeed sympathomimetic on the basis of molecular mechanics studies, since they have been found to fulfill earlier considerations on the minimal structural requirements, necessary to attain high affinity to dopamine (DA) receptors. Furthermore the prepared 1,2‐diamino compounds were used as ligands for the synthesis of cis‐Platinum(II) complexes.
Synthesis of amino derivatives of 5‐aralkylidene‐3‐pyrrolin‐2‐ones
Authors: Adembri G. , Anselmi C. , Camparini A. , Rossetti M. G. , Scotton M. 
Published: April 2009

AbstractPreparation of some derivatives of 5‐aralkylidene‐3‐pyrrolin‐2‐ones is reported. Compounds with an amino group on the phenyl ring at the 3‐position of the pyrrolinone ring showed suitable properties as potential UV‐A filters. Some of the compounds were quaternarized to enhance their solubility in aqueous solvents.
A convenient synthesis of amino‐substituted 1,3,5‐oxadiazinium salts
Authors: Al‐Talib Mahmoud , Tashtoush Hasan 
Published: April 2009

AbstractDiacyl chlorides react with dialkylcyanamide in the presence of a Lewis acid to give amino‐substituted bis‐1,3,5‐oxadiazinium salts in excellent yields. A mechanism leads to the formation of the product has been postulated. All new compounds have been characterized by 1H‐nmr, 13C‐nmr, ir‐spectroscopy and elemental analysis.
A novel urocanic acid derivative from skin tissue extracts; (E)‐3‐[1‐(1,1‐dimethyl‐3‐oxobutyl)imidazol‐4‐yl]propenoic acid
Authors: Ienaga Kazuharu , Yamamoto Atsushi , Yamada Toshio , Joh Yoshinori 
Published: April 2009

AbstractA novel derivative of urocanic acid (1) had been isolated from acetone extracts of rabbit skin tissue. It proved to be (E)‐3‐[1‐(1,1‐dimethyl‐3‐oxobutyl)imidazol‐4‐yl]propenoic acid (3c), potentially a much better ultraviolet screening agent than urocanic acid. Sterical effect of dimethyl groups in the side chain adjacent to the imidazole ring of 3c on its solubility is also discussed.
Dibromotriphenylphosphorane promoted synthesis of condensed heterocyclic systems from aromatic diamines
Authors: Al‐Khathlan Hamad , Zimmer Hans 
Published: April 2009

AbstractA new and rather widely applicable method for the synthesis of a number of tri, tetra‐, and pentacyclic compounds from ortho‐aminodiacylarylimides and dibromotriphenylphosphorane via an intramolecular cyclization is reported. A mechanism for this cyclization is proposed.
Benzimidazole condensed ring systems. 1. Syntheses and biological investigations of some substituted pyrido[1,2‐a]benzimidazoles
Authors: Rida Samia M. , Soliman Farid S. G. , Badawey El‐Sayed A. M. , El‐Ghazzawi E. , Kader O. , Kappe Thomas 
Published: April 2009

AbstractThe synthesis of some substituted 3‐hydroxy‐1‐oxo‐1H,5H‐pyrido[1,2‐a]benzimidazole‐4‐carbonitriles and 4‐ethyl carboxylates 3 and their 0‐ and N‐dialkyl derivatives 5,6 is described. 3‐Ethoxy‐5‐ethyl‐2‐phenyl‐1H,5H‐pyrido[1,2‐a]benzimidazol‐1‐one 7 was obtained during the course of ethylating the parent ester 3t with triethyl phosphate. Chlorination of 3 with phosphorus oxychloride afforded the corresponding 1,3‐dichloropyrido[1,2‐a]benzimidazoles 8 which were converted to a variety of azido, amino, morpholino and methoxy derivatives of the system. The synthesis of the indolopyridobenzimidazole 15 is also described. Two compounds exhibited in vitro antibacterial activity. Many compounds were screened for antileukemic, antimicrobial, herbicidal and plant antifungal potencies but were inactive.
Studies on the chemistry of O,N‐ and S,N‐containing heterocycles. 3. Synthesis of 1,5‐benzothiazepines with potential CNS activity
Authors: Bartsch Herbert , Erker Thomas 
Published: April 2009

AbstractThe synthesis of a series of novel triazolo[3,4‐d][1,5]benzothiazepines 6 and 7, obtained from the activated 1,5‐benzothiazepine derivatives 3 and carbohydrazides 4, is described. Under mild reaction conditions some intermediates 5 can be isolated.
Direct synthesis of 2,4‐diaminoquinazolines from 2‐fluorobenzonitriles
Authors: Hynes John B. , Pathak Alpana , Panes Constantina H. , Okeke Claudia C. 
Published: April 2009

AbstractIn a search for new methods for preparing 2,4‐diaminoquinazolines having a diversity of substituents in the benzenoid ring, it was found that the reaction of 2,6‐difluorobenzonitrile with guanidine carbonate gave 2,4‐diamino‐5‐fluoroquinazoline in excellent yield. Extension of this approach to other 2‐fluorobenzonitriles, some of which were elaborated for the first time, showed that this reaction possesses considerable generality. The cyclization was successful even when electron donating groups were present at position six. Only in two cases where a primary or secondary amino group was also present ortho to the cyano group was this transformation unsuccessful.
Reaction of pyrazine‐2,3‐dicarbonitrile and 1,3‐dimethyllumazine with the phthalimidoalkyl radical
Authors: Tada Masaru , Totoki Shintaro 
Published: April 2009

AbstractA phthalimidoalkyl radical reacts with pyrazine‐2,3‐dicarbonitrile (1) to give mono‐ and diphthalimido‐alkylpyrazine‐2,3‐dicarbonitriles 4 and 5. A similar reaction with 1,3‐dimethyllumazine (2) gave only monophthalimidoalkyl‐1,3‐dimethyllumazines 6 or 7. Hydrazine degradation of 7‐(3′‐phthalimido)propyl‐1,3‐dimethyllumazine (6c) gave a 7‐(3′‐amino)propyl derivative 8 but 7‐phthalimidomethyl‐1,3‐dimethyllumazine (6a) gave only 1,3‐dimethyllumazine (2). Thus the phthalimidomethyl group can be used as a protection group of the pteridine nucleus.
Synthesis of 2,3‐diaryl‐1,4‐diazolyl‐2,3‐epoxybutanes
Authors: Moreno‐Mañas M. , Teixidó M. 
Published: April 2009

Abstract2,3‐Diaryl‐1,4‐diazolyl‐2,3‐epoxybutanes have been prepared from dimethylstilbenes. An efficient although neglected synthesis of the required olefins has been recovered from the literature. The target compounds show moderate antifungal activity.
Pyrimidines, Part XXXI. Synthesis, reactions and properties of 6‐acyl‐1,3‐dimethylpyrrolo[2,3‐d]pyrimidine‐2,4‐diones
Authors: Salih Zuhair S. , Stegmüller Peter , Pfleiderer Wolfgang 
Published: April 2009

AbstractAcylations of 1,3‐dimethyl‐ (1) and 1,3,7‐trimethylpyrrolo[2,3‐d]pyrimidine‐2,4‐dione (2) with anhydrides in the presence of trifluoroacetic acid proceed well to give in good yields the corresponding 7‐acyl derivatives 3–11. The 6‐trichloroacetyl derivatives 5 and 6 are sensitive towards nucleophiles, which displace the trichloromethyl group easily by formation of the corresponding 6‐carboxylic acid derivatives 12–23. The newly synthesized compounds have been characterized by elemental analysis, uv and 1H nmr spectra and pKa, determinations.
Synthesis of ethyl 2‐[(1‐aryl‐1H‐1,2,4‐triazol‐3‐yl)oxy]propionates and related derivatives
Authors: Beck James R. , Babbitt George E. , Lynch Michael P. 
Published: April 2009

AbstractAlkylation of 1‐aryl‐1H‐1,2,4‐triazol‐3‐ols with ethyl 2‐bromopropionate under basic conditions resulted in the formation of 2‐[(1‐aryl‐1H‐1,2,4‐triazol‐3‐yl)oxy]propionic acid, ethyl esters. No N‐alkylated products were detected. Similar alkylation of 2‐oxo‐5‐phenyl‐1,3,4‐thiazole and the corresponding 1,3,4‐oxadiazole gave only N‐alkylated derivatives. With 4‐hydroxy‐6‐phenylpyrimidine and 2‐oxo‐4‐phenylthiazole, both O‐ and N‐alkylation occurred. Structure assignments were based on ir and 13C nmr spectral data.