bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 1H‐thieno[3,4‐c]pyrazoles, thieno[3,4‐b]furans, selenolo[3,4‐b]furans and pyrrolo[3,4‐d]thiazoles
Authors: Shafiee A. , Ebrahimzadeh M. A. , Shahbazi J. , Hamedpanah S. 
Published: March 2009

AbstractStarting from the readily available aryl 2‐methyl‐5‐phenyl‐3‐furyl ketones, 5‐methyl‐1H‐1‐phenylpyrazole‐4‐yl ketones and 4‐methyl‐2‐phenyl‐5‐thiazolylcarboxaldehyde, a series of 2‐phenyl‐4‐arylthieno[3,4‐b]‐furan, 2‐phenyl‐4‐(p‐methoxyphenyl)selenolo[3,4‐b]furan, 4‐aryl‐1H‐1‐phenylthieno[3,4‐c]pyrazole and 5‐benzyl‐2‐phenylpyrrolo[3,4‐d]thiazole were prepared in high yield.
1,3‐Dipolar cycloaddition of 1,2‐o‐isopropylidene‐α‐d‐xylopentadialdo‐1,4‐furanosenitrile oxide to some alkenes
Authors: Fascio Mirta L. , Montesano Verónica J. , D'Accorso Norma B. 
Published: March 2009

AbstractThe synthesis of five 3‐(1,2‐O‐isopropylidene‐α‐D‐xylofuranosyl)‐5‐substituted‐2‐isoxazolines obtained by 1,3‐dipolar cycloaddition are described, as well as the intermediate products from the synthetic route. The physical and spectroscopic characterization of these compounds are reported.
A novel reaction of (2a7‐trinito‐9H‐fluoren‐9‐ylidene)‐propanedinitrile with N‐arylisoindolines
Authors: Hassan Alaa A. , Döpp Dietrich , Henkel Gerald 
Published: March 2009

AbstractN‐Arylisoindolines 1a‐c reacted with (2,4, 7‐trinitro‐9H‐fluoren‐9‐ylidene)propanedinitrile (A) in pyridine with admission of air via a net α‐H‐atom abstraction and formation of [3‐(2‐aryl‐3‐arylimino‐2,3‐dihydro‐ 1H‐isoindol‐1‐ylidene)‐2‐aryl‐2,3‐dihydro‐1H‐isoindol‐1‐ylidene]propanedinitriles 2a‐c, N‐[2‐aryl‐3‐(2‐aryl‐3‐arylimino‐2,3‐dihydro‐1H‐isoindolyl‐1‐idene)‐2,3‐dihydro‐1H‐isoindol‐1‐ylidene]arenamines 3a, b, N, N'‐[2‐aryl‐1H‐isoindole‐1,3(2H)‐diylidene]bisarenamines 4a, b and N‐arylphthalimides 5a‐c in moderate yields. 2,4,7‐Trinitro‐9‐fluorenone as well as one reduction product each of the latter and of A, namely compounds 6 and 7, respectively, are also found. The structure of 2b has been unambiguously confirmed by an X‐ray crystal structure analysis. A rationale for the conversions observed is presented. These involve dehydrogenation and oxidative couplings of 1a‐c as well as transfer of N‐aryl fragment from 1a‐c to intermediate products.
The solid‐state michael addition of 3‐methyl‐1‐phenyl‐5‐pyrazolone
Authors: Li Xiao‐Liu , Wang Yong‐Mei , Tian Bing , Matsuura Teruo , Meng Ji‐Ben 
Published: March 2009

AbstractA novel solid‐state Michael addition between pyrazolone 1 and 4‐arylidenepyrazolones 2 at ambient temperature produced Michael adducts, 4,4′‐arylidenebis(3‐methyl‐1‐phenyl‐5‐pyrazolones) 3. Pyrazolones 3 formed salts 4 with Cu2+ in solution, indicating the enolic structure of the pyrazolone rings. The reactivity of 2 with 1 is discussed in terms of the electronic and steric effects of the substituent on the arylidene group of compounds 2. Pyrazolone 1 also underwent the solid state Michael addition reaction with maleimide at 100° to give the adducts 7,8 and 9.
Facile synthesis of fused purines from 8‐aminotheophylline
Authors: Ueda Taisei , Oh Rikisei , Nagai Shin‐Ichi , Sakakibara Jinsaku 
Published: March 2009

AbstractFused purines 3a‐f were prepared by one‐step from 8‐aminotheophylline (1) and α,ω‐dibromoalkanes in N, N‐dimethylformamide in the presence of sodium hydride. Reaction of 3c‐e with chloroacetyl chloride followed by treatment with dimethylamine gave 6a‐c. A one‐step reaction of 1 with ethyl bromopropionate gave 1,3‐dimethyl‐1,2,3,4,6,7,8,9‐octahydropyrimido[2,1‐f]purine‐2,4,8‐trione (7b). Facile syntheses of 7a, c, d from 1 were also carried out.
Synthesis of pyrimido[4,5‐b]quinolines in the reaction of 6‐aminopyrimidines with dimedone and benzaldehydes
Authors: Quiroga J. , Hormaza A. , Insuasty B. , Ortíz A. J. , Sánchez A. , Nogueras M. 
Published: March 2009

AbstractThe reaction of 6‐aminopyrimidines 1a, b with dimedone (2) and p‐substituted benzaldehydes 3a‐d in ethanol afforded in all cases new regiospecific synthesis of tricyclic, linear 5‐aryl‐5,6,7,8,9,10‐hexahydropyrimido[4,5‐b]quinolines 4a‐h in good yields. The linear structures and hence the regiospecificity of the reaction were established by nmr measurements.
Synthesis of the methanesulfonates of α‐(4‐chlorophenyl)‐α‐[1‐(2‐chlorophenyl)emenyl]‐1H‐1,2,4‐triazole‐1‐ethanol and α‐[1‐(2‐chlorophenyl)ethenyl]‐α‐(2,4‐difluorophenyl)‐1H‐1,2,4‐triazole‐1‐ethanol, alpha styryl carbinol antifungal agents
Authors: Pesti Jaan A. , Downard Jill A. , Lauritsen Mark D. , Kauffman Goss S. , Bryant Walter M. , Huhn George F. , Arnett John F. , Yule Robert E. , Segretario James , Nelson Kimberly A. , Gorko Edward F. , Page Gary O. , Lloyd Lisa M. , Olson Richard E. , Bamum Christopher S. , Mrowca Joseph J. 
Published: March 2009

AbstractThe methanesulfonates of (α‐(4‐chlorophenyl)‐α‐[1‐(2‐chlorophenyl)ethenyl]‐1H‐1,2,4‐triazole‐1‐ethanol and α‐[1‐(2‐chlorophenyl)ethenyl]‐α‐(2,4‐difluorophenyl)‐1H‐1,2,4‐triazole‐1‐ethanol (1a, b) are orally effective α‐styryl carbinol derivatives developed for the treatment and prevention of systemic fungal infections. Practical new processes amenable for the large‐scale production of these compounds are described. Of note is the selection of dichlorostyrene as a convenient precursor of the styryl portion, modification of a sensitive Grignard addition into a realistic preparative reaction and the use of 1,2,4‐triazole simultaneously as a base transfer agent and nucleophile.
A new simple synthesis of 3,5‐disubstituted 1‐amino‐1,3,5‐triazine‐2,4,6‐triones from ethoxycarbonylhydrazones and isocyanates
Authors: Chau François , Malanda Jean‐Claude , Milcent René 
Published: March 2009

AbstractThe 3,5‐disubstituted 1‐amino‐1,3,5‐triazine‐2,4,6‐triones were synthesized in good yields from aromatic aldehyde or ketone ethoxycarbonylhydrazones by treatment with aryl or methyl isocyanates in boiling triethylamine followed by hydrolysis with hydrochloric acid solution.
Synthesis of 6‐cyanopyrido[2,3‐d]pyrimidinones in the reaction of 6‐amino‐4‐pyrimidinones with arylidene derivatives of malonodinitrile
Authors: Quiroga Jairo , Alvarado Mario , Insuasty Braulio , Nogueras Manuel , Sánchez Adolfo , Cobo Justo 
Published: March 2009

AbstractThis paper describes the synthesis of a new series of 7‐amino‐5‐aryl‐6‐cyano‐5,8‐dihydropyrido‐[2,3‐d]pyrimidin‐4(3H)‐ones 3 from the reaction of 6‐amino‐4‐pyrimidinones 1 with arylidene derivatives of malonodinitrile 2. The structure of the final compounds was determined on the basis of nmr measurements, especially by 1H, 1H‐, 1H, 13C COSY, DEPT, HMBC and HMQC experiments.
Syntheses and properties of chiral pentahomothiazacalix[3]arenes
Authors: Ito Kazuaki , Ohba Yoshihiro , Sone Tyo 
Published: March 2009

AbstractChiral calixarene analogs incorporating an aminoethanethiol unit such as L‐cysteine into their rings were prepared. Conformational analysis of the macrocycles by using 1H and 13C nmr spectroscopy revealed that their preferred conformation was a cone, which was more stable in chloroform than in toluene. The introduction of an aminoethanethiol moiety into the macrocyclic ring caused ring fluctuation, however, the carboxylic acid derivative was a highly rigid structure in the cone form. The 1H nmr and circular dichroism spectra of the macrocycles showed the existence of chirality of the phenol‐formaldehyde unit, which was induced by the chirality of the cysteine moiety.
Synthesis of the bi‐heterocyclic parent ring system 1,2,4‐triazolo[4,3‐b][1,2,4,5]tetrazine and some 3,6‐disubstituted derivatives
Authors: Chavez David E. , Hiskey Michael A. 
Published: March 2009

AbstractThe synthesis of the previously unknown parent ring system was developed. Treatment of 3‐hydrazino‐1,2,4,5‐tetrazine (4) with diethoxymethyl acetate gave the parent ring system. Similar treatment of 3‐(3,5‐dimethylpyrazol‐1‐yl)‐6‐hydrazino‐1,2,4,5‐tetrazine (2) with one carbon cyclizing reagents gave 3,6‐di‐substituted derivatives of the 1,2,4‐triazolo‐1,2,4,5‐tetrazine ring system.
Reactions of 2‐aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates with hydroxylamine and hydrazines
Authors: Wang Dao‐Lin , Imafuku Kimiaki 
Published: March 2009

Abstract2‐Aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates1a‐creacted with hydroxylamine hydrochloride and hydrazine sulfate in the presence of triethylamine to afford 2‐aryl‐4,9‐dihydrocyclohepta[b]pyran‐4,9‐dione 4‐oximes3a‐cand 4‐hydrazones4a‐cin good yields, respectively. On the other hand, the reactions with methylhydrazine and phenylhydrazine gave respectively 1‐methyl‐ and 1‐phenyl‐substituted 5‐aryl‐3‐(3‐tropolonyl)pyrazoles5a‐cand6a‐cin excellent yields. Treatment with 4‐nitrophenylhydrazine gave 2‐aryl‐4,9‐dihydrocyclohepta[b]pyran‐4,9‐dione 4‐(4‐nitrophenyl)hydrazones7a‐cin good yields.
Cryptolepinone vs. Hydroxycryptolepine: Resolution of a question of substituent functionality and double bond isomerization
Authors: Sharaf Maged H. M. , Schiff Paul L. , Tackie Albert N. , Martin Gary E. 
Published: March 2009

AbstractAn indolo[3,2‐b]quinoline alkaloid bearing an N‐methyl substituent at N5, and an oxygen moiety at the 11‐position has been variously described as both cryptolepinone and 11‐hydroxycryptolepine by independent research groups. The structure of this alkaloid is unequivocally confirmed as the former, cryptolepinone, with substantial changes in double bond isomerization relative to that which would be required if it were indeed the latter. The structure of the alkaloid was confirmed by, total assignment of the 1H, 13C, and 15N nmr spectra at natural abundance using 3 mm micro inverse nmr probe technology at 400 and 500 MHz.
Chemoselective synthesis of 1‐alkyl‐4‐(4‐amino‐2,6‐dichlorophenoxy)‐5‐halopyridazin‐6‐ones
Authors: Kweon Deok‐Heon , Chung Ju‐Wha , Cho Su‐Dong , Kim Sung‐Kyu , Yoon Yong‐Jin 
Published: March 2009

AbstractSome 1‐alkyl‐4‐(4‐amino‐2,6‐dichlorophenoxy)‐5‐halopyridazin‐6‐ones were synthesized chemoselectively from 1‐alkyl‐4,5‐dihalopyridazin‐6‐ones and 4‐amino‐2,6‐dichlorophenol via a fluoride ion‐assisted reaction.
Pyridazines. XV. Synthesis of 6‐aryl‐5‐amino‐3(2H)‐pyridazinones as potential platelet aggregation inhibitors
Authors: Estevez Isabel , Raviña Enrique , Sotelo Eddy 
Published: March 2009

AbstractSeveral 3(2H)‐pyridazinones with amino groups at the 5‐position of the pyridazine nucleus have been prepared. The 6‐aryl‐5‐halo‐3(2H)‐pyridazinones obtained from mucochloric and mucobromic acid lead to the corresponding 5‐alkylamino‐3(2H)‐pyridazinones, which were tested as platelet aggregation inhibitors.
Computational investigation of the suitability of heterocyclic aromatic compounds with two heteroatoms in the 1 and 3 ring positions as dienes for the diels alder reaction
Authors: Jursic Branko S. 
Published: March 2009

AbstractSemiempirical and density functional theory computational studies were carried out with the target determining the reactivity of five membered heterocycles with heteroatoms in the 1 and 3 positions as dienes for Diels‐Alder reactions. The relative reactivity was evaluated in their reaction with acetylene, ethylene, and cyclopropene as dienophiles for cycloaddition. Qualitative criteria such as uniformity of heterocycle bond orders, change of bond orders and frontier molecular orbital energies in transformation of reactants into transition state structures were used to determine the relative reactivity in comparison with furan. These results are compared with the computed activation barriers as well as with experimental findings, where available. If cycloaddition is feasible with these heterocycles, a new synthetic transformation of simple organic compounds to valuable prostaglandin derivatives can be accomplished.
Synthesis of pyrazolecarbonylaminopyridinecarboxamides as herbicides
Authors: Parlow John J. 
Published: March 2009

AbstractTarget compounds from a herbicide lead area, pyrazolecarboxamides, were selected and synthesized. These targets were chosen based on 1) “structural” similarities of 2a‐c with other known bleaching herbicides, and 2) the structure activity relationship previously established with analogs of the lead compound 2a. Syntheses of three target compounds were accomplished, two of which involved various transformations and regioselective additions with a pyridine nucleus to afford novel pyridine derivatives. These targets were tested in whole plant assays with the herbicidal data reported.
Steric promotion of cyclization reactions: Substituent effect studies in the furan intramolecular diels‐alder reaction
Authors: Mcnelis Brian J. , Starr Jeremy T. , Dang Hung 
Published: March 2009

AbstractSeven alkyl and aryl substituted N‐allyl‐N‐(methylfuran)‐sulfonamide compounds have been synthesized and their rates of cyclization and equilibrium product concentrations determined. Increased steric bulk on the sulfonamide substituent has been shown to increase both the rate of cyclization and yields of these reactions. A three‐fold increase in rate and 15% increase in yield was observed as the substituent was varied from methyl to triisopropylbenzene.
A convenient synthesis of 2‐amino‐4H‐1,3,4‐oxadiazino[5,6‐b]‐quinoxaline derivatives
Authors: Kim Ho Sik , Kim Tong Eun , Lee Seong Uk , Kim Dong Il , Han Sung Wook , Okamoto Yoshihisa , Mitomi Takako , Kurasawa Yoshihisa 
Published: March 2009

AbstractThe reaction of 6‐chloro‐2‐(1‐methylhydrazino)quinoxaline 4‐oxide 5 with a 2‐fold molar amount of ethyl chloroglyoxalate gave ethyl 8‐chloro‐4‐methyl‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxaline‐2‐carboxylate 6, whose reaction with hydrazine hydrate afforded the C2‐hydrazinocarbonyl derivative 7. The reaction of compound 7 with nitrous acid provided the C2‐acylazide derivative 8, which was converted into the C2‐amino 9, C2‐carbamate 11a‐c, 12a,b, and C2‐ureido 13a‐c, 14 derivatives. The mass spectral fragmentation patterns were examined for compounds 10–14, wherein the molecular ion peak did not appear in the mass spectra of compounds 10c, 11a‐c, 12a,b, 13c, and 14.
A facile one‐pot synthesis of 2,5‐disubstituted oxazoles using iodobenzene diacetate
Authors: Varma Rajender S. , Kumar Dalip 
Published: March 2009

AbstractA facile one‐pot synthesis of oxazoles 1a‐h is described that utilizes readily available aromatic α‐methyl ketones and a safe hypervalent iodine reagent, iodobenzene diacetate.
Manganese triacetate oxidation of phenolic schiffs bases: Synthesis of 2‐arylbenzoxazoles
Authors: Varma Rajender S. , Kumar Dalip 
Published: March 2009

AbstractA concise synthesis of 2‐arylbenzoxazoles, 5a‐f, is described that occurs via the oxidative cyclization of Schiff's bases, 1a‐f, using relatively benign reagent, manganese triacetate.
Structure and properties of ethyl (2‐benzimidazolyl)cyanoacetimidate
Authors: Yamaguchi Yoshimi , Okamoto Yoshihisa , Harada Kazuho 
Published: March 2009

AbstractThe revision of the structure of hydrolytic product from 4‐cyano‐1‐ethoxypyrirnido[1,6‐a]benzimidazole (1) and the properties of ethyl (2‐benzimidazolyl)cyanoacetimidate (3a) are described.
Successive electron transfer reaction of the lithium salt of 5‐methyl‐5,10‐dihydrophenazine anion with 4‐nitrophenethyl bromide via 4‐nitrostyrene
Authors: Sugimoto Akira , Maruyama Hideyuki , Takahashi Wataru , Mizuno Kazuhiko , Uehara Kaku , Adachi Tomohiro 
Published: March 2009

AbstractThe reaction of lithium salt of 5‐methyl‐5,10‐dihydrophenazine anion with 4‐nitrophenethyl bromide in 1,2‐dimethoxyethane gave unexpected compounds, 1,2‐bis[5‐(10‐methyl‐5,10‐dihydrophenazinyl)]‐1‐(4‐nitrophenyl)ethane and 1,4‐bis(4‐nitrophenyl)‐1,4‐bis[5‐(10‐methyl‐5,10‐dihydrophenazinyl)]butane, while the reaction in dimethyl sulfoxide brought about the formation of 5‐methyl‐10‐(4‐nitrophenethyl)‐5,10‐dihydrophenazine. The successive electron transfer mechanism is proposed for the former reaction via 4‐nitrostyrene.
Reactions of arylglyoxals with tetrasulfur tetranitrides (S4N4): Formation of 2‐aroyl‐5‐arylimidazoles and 2‐aroyl‐5‐aryloxazoles
Authors: Kong Yung Cheol , Kim Kyongtae 
Published: March 2009

AbstractTreatment of arylglyoxal monohydrates with tetrasulfur tetranitride in p‐dioxane at reflux afforded 2‐aroyl‐5‐arylimidizoles and 2‐aroyl‐5‐aryloxazoles in 10 to 31% and 17 to 32% yields, respectively. With non‐hydrate of arylglyoxals, yields of the latter increase somewhat, whereas essentially no changes in yields of the former were observed. A mechanism is proposed for the formation of the products.
Synthesis and conformational analysis of a chiral fluorinated bilirubin analog lacking carboxyl groups
Authors: Boiadjiev Stefan E. , Lightner David A. 
Published: March 2009

AbstractAn optically active analog 1 of etiobilirubin‐IVγ with a single fluorine on each of the C(8) and C(12) alkyl groups has been synthesized in order to examine its potential for hydrogen bonding with fluorine. Circular dichroism spectroscopy reveals an unusually strong influence of 2,2,2‐trifluoroethanol solvent on diastereo‐selection of the M‐helical conformation of (81S,121S)‐1.
1,6‐ and 1,7‐naphthyridines. II. Synthesis from acyclic precursors
Authors: Blanco M. Mercedes , Perillo Isabel A. , Schapira Celia B. 
Published: March 2009

AbstractA number of 8‐hydroxy‐6‐methyl‐1,6‐naphthyridin‐5(6H)‐one‐7‐carboxylic acid alkyl esters 3 and the isomeric 5‐hydroxy‐7‐methyl‐1,7‐naphthyridin‐8(7H)‐one‐6‐carboxylic acid alkyl esters 4 were synthesized from acyclic precursors obtained starting from quinolinic anhydride 5. Thus, methanolysis of 5 afforded the hemiester 6 which treated with oxalyl chloride and sarcosine ethyl ester gave 3‐(N‐ethoxycarbonylmethyl‐N‐methylcarbamoyl)pyridine‐2‐carboxylic acid methyl ester 8. Compound 8 was cyclized to naphthyridines 3a‐e with sodium alkoxides. The isomeric naphthyridines 4a‐c were obtained by cyclization of the open intermediary 2‐(N‐ethoxycarbonylmethyl‐N‐methylcarbamoyl)pyridine‐3‐carboxylic acid methyl ester 9 obtained by a route that involves treatment of 5 with sarcosine ethyl ester and esterification with diazomethane. Spectroscopic properties (1H nmr, uv, ir) of compounds 3 and 4 are discussed and confirmed the proposed structures.
Pyridazine derivatives. XIX: Functionalization studies at the 5 position in the 6‐phenyl‐3(2H)‐pyridazinone system
Authors: Sotelo Eddy , Raviña Enrique , Estevez Isabel 
Published: March 2009

AbstractA series of 6‐phenyl‐3(2H)‐pyridazinones bearing different substitution at the 5 position of the pyridazinone ring were prepared in the search for new platelet aggregation inhibitors. The structure of the final compounds was determined on the basis of spectroscopics methods.
Intramolecular oxidative cyclizations in heteroarylthioureas: A versatile pathway to bridgehead heterocyclic systems
Authors: Castro Ana , Martinez Ana 
Published: March 2009

AbstractIntramolecular oxidations in N‐alkyl‐N'‐heteroarylthioureas represent a facile and versatile synthetic pathway to fused heterocyclic systems including the bridgehead ones. This kind of heterocycles are the main feature in commom biologically active compounds.
Synthesis of 3‐phenoxy‐1,3‐dihydro‐1‐isobenzofuranones by palladium‐catalyzed carbonylative cyclization of 2‐bromobenzaldehyde with phenols
Authors: Cho Chan Sik , Baek Dong Yeol , Shim Sang Chul 
Published: March 2009

Abstract2‐Bromobenzaldehyde reacts with phenols in acetonitrile under carbon monoxide pressure in the presence of a catalytic amount of bis(triphenylphosphine)palladium(II) chloride to afford the corresponding 3‐phenoxy‐1,3‐dihydro‐1‐isobenzofuranones in high yields.
The directed ortho metalation — Cross‐coupling symbiosis in heteroaromatic synthesis
Authors: Green Laine , Chauder Brian , Snieckus Victor 
Published: March 2009

AbstractThirty years after its discovery by Gilman and Wittig, the Directed ortho Metalation (DoM) reaction continues to march in synthetically useful paths. To offer evidence for this statement, this lecture review describes a new and general cumyl Directed Metalation Group (DMG) (Schemes 2–6) and a phosphine oxide DMG (Schemes 7 and 8). Aryl‐aryl cross‐coupling chemistry is highlighted by polymer support Suzuki‐Miyaura (Schemes 10 and 11) and an aryl O‐carbamate‐Grignard of value in the construction of naphthalenes (Scheme 12) and indoles (Scheme 13) and, for the latter class of compounds, in the generation of 4,5‐quinodimethane intermediates (Scheme 14) for the synthesis of corresponding annelated derivatives (Scheme 15). The marriage of DoM with the Negishi cross‐coupling reaction is demonstrated in general (Scheme 16). The concept of Directed remote Metalation (DreM) (Schemes 17 and 19) is applied to the synthesis of dibenzopyranones (Scheme 18), xanthones (Scheme 21), acridones, dibenzoazepinones, and oxindoles (Scheme 20). In this context, a carbanionic N‐to‐ortho‐C t‐Boc migration leading to anthranilate esters is also achieved (Scheme 20). For provision of diaryl ethers, diaryl sulfides, and diaryl amines, a new copper catalyst is introduced into the venerable Ullmann reaction (Scheme 22) and its extension by DoM, and cross‐coupling chemistry is indicated (Scheme 23). A recently evolving link to DoM, the Grubbs metathesis process is manifested in the total synthesis of two natural products (Schemes 25 and 26) and has anticipated use more broadly in heterocyclic synthesis. (Scheme 27).
Synthesis of two 1,3‐2,4‐calix[4]bis‐crown ethers containing two 1,2‐phenylene and one pyridine or anisole units in each crown ether moiety
Authors: Xue Guo‐Ping , Bradshaw Jerald S. , Su Ning , Krakowiak Krzysztof E. , Savage Paul B. , Izatt Reed M. 
Published: March 2009

AbstractSyntheses of 1,3–2,4‐calix[4]bis‐crown ethers (1 and 2) fixed in the 1,3‐alternate conformation by 1,3‐ and 2,4‐bridges made of two modified polyether chains each containing two 1,2‐phenylene residues and one pyridine or anisyl unit are reported. The structures of compounds 1 and 2 were established by 1H nmr, 13C nmr, hrms and elemental analyses.
Isolation and structural data of the opened ring derivative of a 1,2,4‐triazolothieno‐1,4‐diazepine
Authors: Legouin Béatrice , Burgot Jean‐Louis 
Published: March 2009

AbstractThe preparation of the trihydrochloride form of 2‐[3‐(aminomethyl)‐5‐methyl‐1,2,4‐triazol‐4‐yl]‐3‐(2‐chlorobenzoyl) thieno[2,3‐c]‐4,5,6,7‐tetrahydropyridine (2) the ring opened derivative of a 1,2,4‐triazolo‐thieno‐1,4‐diazepine is described. Its structural properties are given, and are compared with those of the corresponding closed form 4H‐6‐(2‐chlorophenyl)‐1‐methyl‐7,8,9,10‐tetrahydropyrido[4′,3′:4,5]thieno[3,2‐f]‐[1,2,4]triazolo[4,3‐a][1,4]diazepine (1).
Syntheses of some new coumarin‐quinolone carboxylic acids
Authors: Trkovnik Mladen , Ivezić Zrinka 
Published: March 2009

AbstractAminocoumarin derivatives 3‐10 were condensed with diethyl ethoxymethylenemalonate to give intermediates 11‐18. Thermal cyclizations of intermediates give benzopyranopyridinecarboxylates 19‐26. These esters were hydrolyzed to the corresponding benzopyranopyridine carboxylic acids 27‐34.
Synthesis of some novel derivatives of 1,10‐phenanthroline
Authors: Garas Adel M. S. , Vagg Robert S. 
Published: March 2009

AbstractThe synthesis is described of a set of new N‐heterocyclic compounds which are derivatives of 1,10‐phenanthroline. The compounds are designed to be general purpose chelating agents which could function as tri‐, tetra‐ or hexadentate ligands with transition metal ions. Fused‐ring molecular components have been included in the design of the compounds so that they may function as binding agents to DNA through intercalation. This includes the synthesis of substituted derivatives of pyrazino[2,3‐f][1,10]phenanthroline and dipyrido[3,2‐a:2′3′‐c]phenazine.
New routes to 1‐functionally substituted arylbenzotriazoles: 3‐Benzotriazol‐1‐yl‐pyridazine‐4‐ones, 5‐benzotriazol‐1‐yl‐pyridazine‐6‐ones and 5‐benzotriazol‐1‐yl‐pyridazine‐6‐imines
Authors: Al‐Omran Fatima , Al‐Awadl Nouria , Yousef Osama , Elnagdi Mohamed Hilmy 
Published: March 2009

AbstractCondensation of 1‐arylhydrazono‐1‐benzotriazol‐1‐yl 2‐propanones (5a‐c) with DMF DMA afforded 1‐aryl‐3‐benzotriazol‐1‐yl‐1,4‐dihydropyridazine‐4‐ones (8a‐c). While condensation of 1‐functionally substituted methylbenzotriazoles 3b,c with 2‐arylhydrazono‐3‐oxoarylpropanal 13a,b give 3‐aroyl‐5‐(benzo‐triazolyl‐1‐yl)‐1,6‐dihydro‐1‐phenylpyridazine‐6‐ones and 6‐imines 14a‐d.