bluuebunny/crossref_metadata_2025_split huggingface dataset:
N‐arylhexahydropyrimidines. Part 1. Synthesis and 1H NMR characterization of 1,3‐Di and 1,2,3‐trisubstituted derivatives
Authors: Perillo Isabel A. , García María B. , Bisceglia Juan Á. , Orelli Liliana R. 
Published: March 2009

AbstractA series of N‐arylhexahydropyrimidines la‐1 were synthesized by condensation of N‐aryl‐N'‐alkyl‐ (or aryl)‐1,3‐propanediamines 2a‐h with aldehydes. Reactions with formaldehyde proceeded in hydroalcoholic solution, while condensation with aromatic aldehydes required in general the use of activated molecular sieves. 1H NMR spectra of compounds la‐1 were analyzed and the results correlated with their conforma‐tional features. Derivatives devoid of a 2‐substituent la‐g show fast ring reversal and N‐inversion. The presence of a 2‐aryl group shifts the ring reversal equilibrium towards conformations where the 2‐aryl substituent is equatorial. Differential assignment of axial and equatorial hydrogens in these compounds was made on the basis of coupling constants and chemical shift values. In compound 1k spectral data suggest the axial orientation of the N‐methyl group. Such findings were confirmed in the corresponding NOESY spectrum.
The synthesis and properties of new carbohydrate‐modified mesoionic thiazolo[3,2‐α]pyrimidine‐5,7‐dione acyclonucleosides
Authors: Stoelting Daniel T. , Mbagwu Godwin O. , Scott Tina , Long Michael , Sharpe Elsa L. 
Published: March 2009

AbstractThe synthesis of the first examples of Class II mesoionic thiazolopyrimidine acyclonucleosides (MTA) incorporating the 2,3‐dihydroxypropyl moiety as the sugar simulator is described. First, 2‐bromothiazole was reacted with excess 1‐amino‐2,3‐propanediol acetonide via an aromatic nucleophilic substitution reaction to yield 1‐(2‐thiazolylamino)‐2,3‐propanediol acetonide. This acetonide intermediate was condensed at 160° with substituted bis(2,4,6‐trichlorophenyl) malonic esters to form a series of protected acyclonucleosides termed anhydro‐(8‐((2,2‐dimethyl‐1,3‐dioxolan‐4‐yl)methyl)‐5‐hydroxy‐7‐oxothiazolo[3,2‐a]pyrimi‐dinium hydroxides) which differ in their 6‐position substituent. Deprotection of these acyclonucleosides using p‐toluenesulfonic acid catalyst in methanol at 65° yielded the desired Class II MTA, anhydro‐(8‐(2,3‐dihydroxypropyl)‐5‐hydroxy‐7‐oxothiazolo[3,2‐a]pyrimidinium hydroxides).
Synthesis of 3‐aryl‐5‐styryl‐2‐pyrazolines by the reaction of (E,E)‐cinnamylideneacetophenones with hydrazines and their oxidation into pyrazoles
Authors: LÉvai Albert , Patonay TamÁs , Silva Artur M. S. , Pinto Diana C. G. A. , Cavaleiro José A. S. 
Published: March 2009

AbstractNew 3‐aryl‐5‐styryl‐2‐pyrazolines have been synthesized by the reaction of (E,E)‐cinnamylideneace‐tophenones with hydrazines. These 2‐pyrazolines have also been converted into the corresponding pyrazoles by oxidation with chloranil. Structures of all new compounds have been elucidated by elemental analysis, mass spectrometry, ir and nmr spectroscopic measurements.
Novel syntheses of polysubstituted pyrroles and oxazoles by 1,3‐dipolar cycloaddition reactions of benzotriazole‐stabilized nitrile ylides
Authors: Katritzky Alan R. , Zhang Suoming , Wang Mingyi , Kolb Hartmuth C. , Steel Peter J. 
Published: March 2009

Abstract1,3‐Dipolar cycloadditions of benzotriazole‐stabilized nitrile ylides with benzyl α,β‐unsaturated‐carboxy‐lates and aldehydes as dipolarophiles proceeded smoothly and efficiently to give polysubstituted pyrroles and oxazoles, respectively, in good yields.
Synthesis and molecular structure of novel 4‐aryloctahydropyrido‐[1,2‐c]pyrimidine derivatives
Authors: Herold Franciszek , Kleps Jerzy , Szczȩsna Beata , Anulewicz‐Ostrowska Romana 
Published: March 2009

AbstractA series of new 4‐aryloctahydropyrido[1,2‐c]pyrimidine‐1,3‐diones 6a,b,d‐h and j were synthesized by intramolecular cyclization of α‐aryl‐α‐(1‐ethoxycarbonyl‐2‐piperidyl)‐acetamide derivatives 5a,b,d‐h and j. The structures of compounds were determined by 1H and 13C nmr spectroscopy. Nmr and X‐ray diffraction data indicate that the configuration at the C4, C4a stereocenters constitute RR and SS pair.
Recyclizations of 2‐aminobenzylimines and thioaroylhydrazones of N‐substituted N‐hydroxy‐3‐oxobutanamides
Authors: Zelenin Kirill N. , Lagoda Igor V. , Alekseyev Valeriy V. , Sinkkonen Jari , Pihlaja Kalevi , Shaikhutdinov Roustem A. 
Published: March 2009

AbstractA universal scheme is proposed for the molecular design of heterocyclic recyclizations by replacing the exocyclic hydroxyl groups in exo‐trig‐ ring‐chain tautomeric molecules with substituted amines or hydrazines. The practical applicability of this approach is demonstrated by the condensations of 5‐hydroxy‐5‐methyl‐3‐isoxazolidinones with thioaroyl‐hydrazines and 2‐aminomethylaniline. The condensation products were studied by modern 1H, 13C and 15N NMR spectroscopic methods using three solvents: CDC13, DMSO[D6] and CD3CN. The solvent was found to have a strong effect to the relative amounts of the tautomers.
Synthesis of some new pyridazino cinnoline derivatives
Authors: Soliman A. M. 
Published: March 2009

Abstract2,5‐Dibromo‐3,6‐(dihydrazino or diphenylhydrazino)‐1,4‐benzoquinone 1a,b reacts with active methyl‐ene reagents to give some new functionally substituted pyridazino cinnoline derivatives.
Synthesis and reactions of 6‐methylsulfanyl‐2,4‐dithioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐carbonitrile
Authors: Briel Detlef , Franz Tanja , Dobner Bodo 
Published: March 2009

AbstractThe synthesis of 6‐methylsulfanyl‐2,4‐dithioxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carbonitrile 4 is described. Compound 4 was reacted with various alkylants. The reaction with chloroacetic acid derivatives results in the formation of thieno[2,3‐d]pyrimidines 8. When methyl iodide was used 2,4,6‐tris(methylsul‐fanyl)pyrimidine‐5‐carbonitrile 5 was obtained. The substitution of the methylsulfanyl groups in compound 5 by several N‐nuclophiles leads to amino substituted pyrimidines.
Facile synthesis of model 1,4‐dihydro‐1H‐1,3,4‐benzotriazepin‐5‐ones
Authors: Abu Thaher Bassam A. , Zahra Jalal A. , El‐Abadelah Mustafa M. 
Published: March 2009

Abstract2‐Aminobenzoic acid reacts readily, in the presence of triethylamine, with hydrazonoyl chlorides (5a‐c) (precursors of the reactive nitrile imine 1,3‐dipolar species) to afford high yields of the corresponding acyclic amidrazone adducts (6a‐c). The latter adducts undergo, in THF in presence of 1,1‐carbonyldiimida‐zole, smooth intramolecular cyclization involving the activated carboxyl and the NH‐ termini to deliver unequivocally the respective dihydro‐1,3,4‐benzotriazepin‐5‐ones (7a‐c).
2‐Chloro‐4,5‐dihydroimidazole, Part X. Revisiting route to N‐heteroarylimidazolidin‐2‐ones
Authors: Sa̧czewski Franciszek , Bulakowska Anita , Gdaniec Maria 
Published: March 2009

AbstractThe ureidation reactions of 2‐ and 4‐picoline N‐oxides with 2‐chloro‐4,5‐dihydroimidazole are described. A mechanism of novel thioureidation reaction of 4‐picoline N‐oxide with 2‐(4,5‐dihydro‐1H‐imidazol‐2‐ylthioxy)‐4,5‐dihydro‐1H‐imidazole is proposed. Structural assignment is confirmed by 1H and 13C nmr as well as by X‐ray crystallography.
Synthesis and structural characterisation of 4H‐1,3‐benzothiazine derivatives
Authors: Fodor Lajos , Bernáth Gábor , Sinkkonen Jari , Pihlaja Kalevi 
Published: March 2009

AbstractThe ring‐closure reactions of N‐arylthiomethylaroylamide derivatives (1a‐g) in the presence of phospho ‐rus oxychloride gave 2‐aryl‐4H‐1,3‐benzo‐thiazines (2a‐g). 2‐(3‐Chlorophenyl)‐6‐methyl‐4H‐1,3‐benzoth‐iazine (2b) was reduced with Zn to obtain the corresponding 2,3‐dihydro derivative (3b). Potassium permanganate oxidation of 2‐(4‐chlorophenyl)‐2,3‐diethoxy‐4H‐ (2e) and 2‐(2‐fluorophenyl)‐6,7‐diefhoxy‐4H‐1,3‐benzo‐thiazines (2g) gave the corresponding 4‐ones (4e,g). The reactions of 2‐(4‐chlorophenyl)‐6‐mefhyl‐4H‐1,3‐benzofhiazine (2c) with substituted acetyl chlorides led to linearly condensed ß‐lactams (5a,b). The structures of the compounds studied were confirmed by 1H and 13C NMR and by their characteristic mass spectrometric fragmentations.
Isolation of methyl (RS)‐1‐tert‐butoxycarbonyl‐3‐cyanomethyl‐1,2‐dihydro‐2‐oxo‐5H‐pyrrole‐5‐carboxylate, the key‐intermediate in base‐catalyzed formation of racemic products by 1,3‐dipolar cycloadditions to methyl (S)‐1‐tert‐butoxycarbonyl‐3‐[(E)‐cyanomethylidene]‐2‐pyrrolidinone‐5‐carboxylate
Authors: Škof Marko , Pirc Samo , Rečnik Simon , Svete Jurij , Stanovnik Branko , Golič Ljubo , Selič Lovro 
Published: March 2009

AbstractCycloadditions of various 1,3‐dipoles to methyl (S)‐1‐tert‐butoxycarbonyl‐3‐[(E)‐cyanomethylidene]‐2‐pyrrolidinone‐5‐carboxylate (9) were studied. Reactions of 9 with diazomethane (10) and 2,4,6‐trimethoxy‐benzonitrile oxide (11), carried out under neutral conditions, gave the corresponding optically active spiro compounds 16‐18 with low diastereoselectivity (20‐30% diastereomeric excess). On the other hand, reactions of 9 with nitrile oxide 11 and nitrile imines 14, 15, carried out in the presence of a base, afforded racemic pyrazolo and isoxazolo fused 2‐pyrrolidinones 21‐23 in 82‐86% diastereomeric excess. Optically active dipolarophile 9 was isomerized in the presence of basic alumina to give methyl (RS)‐1‐tert‐butoxy‐carbonyl‐3‐cyanomethyl‐1,2‐dihydro‐2‐oxo‐5H‐pyrrole‐5‐carboxylate (19). Treatment of the racemic dipolarophile 19 with dipoles 11 and 14, afforded fused 2‐pyrrolidinones 23 and 21. These observations support compound 19 as the key‐intermediate in the formation of racemic cycloadducts 21‐23.
Efficient photochemical synthesis of tricyclic keto‐indoles
Authors: Tietcheu Christèle , Garcia Christophe , Gardette Daniel , Dugat Denise , Gramain Jean‐Claude 
Published: March 2009

AbstractTricyclic keto‐indoles were synthesized by photocyclization of easily obtained enaminones in an electro‐cyclic photochemical reaction. The three methods reported were chosen according to the enaminone structure. The most general procedure using one‐step synthesis was carried out in a benzene‐methanol solution in the presence of sodium methylate. In the case of base sensitive substrates, the best method was photocyclization followed by oxidation. Besides, N‐unsubstituted indoles with a five‐membered ring were prepared by a photolysis reaction. All three methods are efficient and easy to perform.
Heterocyclization reaction of 2‐(2‐methylaziridin‐1‐yl)‐3‐ureidopyridines under appel's conditions
Authors: Lim Ji‐Sun , Lee Kee‐Jung 
Published: March 2009

AbstractThe reaction of 2‐(2‐methylaziridin‐1‐yl)‐3‐ureidopyridines12with triphenylphosphine, carbon tetra‐chloride, and triethylamine (Appel's conditions) led to the corresponding carbodiimides13, which underwent intramolecular cycloaddition reaction with aziridine under the reaction conditions to give the pyridine‐fused heterocycles, 2,3‐dihydro‐1H‐imidazo[2′,3′:2,3]imidazo[4,5‐b]pyridines16and 12,13‐dihydro‐5H‐1,3 ‐benzodiazepino [2′,3′:2,3] imidazo[4,5‐b]pyridines17.
Synthesis of new 1,2‐dihydrophthalazines
Authors: Lukács Gyula , Simig Gyula 
Published: March 2009

AbstractNew 6‐chloro‐ and 6,7‐dichloro‐4‐(4‐aminophenyl)‐2‐(N‐alkylcarbamoyl)‐1,2‐dihydrophthalazines (12,18) were synthesized starting from 6‐chloro‐ and 6,7‐dichloro‐4‐(4‐nitrophenyl)phthalazine (8). Routes to 1‐unsubstituted (12) and 1‐methyl (18) derivatives are different. Key intermediates 8 were prepared from 4‐chloro‐ and 3,4‐dichlorotoluene via ortho‐formylbenzophenone derivatives 7.
Synthesis of novel pyrido[3′,2′:5,6]thiopyrano[3,2‐b]indol‐5(6H)‐ones and 6H‐pyrido[3′,2′:5,6]thiopyrano[4,3‐b]quinolines, two new heterocyclic ring systems
Authors: Da Settimo Antonio , Marini Anna María , Primofiore Giampaolo , Da Settimo Federico , Salerno Silvia , Simorini Francesca , Pardi Gianluca , La Motta Concettina , Bertini Daniele 
Published: March 2009

AbstractThe synthesis of new pyrido[3′,2′:5,6]thiopyrano[3,2‐b]indol‐5(6H)‐ones was accomplished by the Fischer‐indole cyclization of some 2,3‐dihydro‐3‐phenylhydrazonothiopyrano[2,3‐b]pyridin‐4(4H)‐ones, obtained from the 2,3‐dihydro‐3‐hydroxymethylenethiopyrano[2,3‐b]pyridin‐4(4H)‐one, by the Japp‐Klingemann reaction.6H‐Pyrido[3′,2′:5,6]thiopyrano[4,3‐b]quinolines were obtained by reaction of 2,3‐dihydrothiopyrano‐[2,3‐b]pyridin‐4(4H)‐ones with o‐aminobenzaldehyde or 5‐substituted isatins. The preparation of some derivatives, functionalized with an alkylamino‐substituted side chain, is also described.
An approach to novel fused triazole or tetrazole derivatives starting from benzimidazo[1,2‐a]quinazoline‐5(7H)‐one and 5,7‐dihydro‐5‐oxopyrido[3′,2′:5,6]pyrimido[1,2‐a]benzimidazole
Authors: Da Settimo Antonio , Primofiore Giampaolo , Da Settimo Federico , Pardi Gianluca , Simorini Francesca , Marini Anna Maria 
Published: March 2009

AbstractThe synthetic potential of the title compounds benzimidazo[1,2‐a]quinazoline‐5(7H)‐one 2a and 5,7‐dihydro‐5‐oxopyrido[3′,2′:5,6]pyrimido[1,2‐a]benzimidazole 2b for the construction of novel polyhetero‐cyclic frameworks is reported. Compounds 2a,b, by conversion into their thio analogues 3a,b, were used for the synthesis of tetrazole (5a,b) and triazole (7a,b) derivatives, as well as for an unexpected synthesis of tri‐azoles 8a,b, isomers of 7a,b, resulting from the occurrence of a Dimroth rearrangement.
Synthesis of pyrrolidine based natural or unnatural product derivatives (1): Application of efficient asymmetric induction of C‐2 position in polysubstituted pyrrolidines
Authors: Jeong Hyung Jae , Lee Ju Man , Kim Min Kyu , Lee Sang‐Gyeong 
Published: March 2009

AbstractA novel method for synthesis of polysubstituted pyrrolidines, which possess a C‐2 stereocenter, was developed. The strategy involves Grignard addition to the succinimide, derived from L‐tartaric acid, followed by stereocontrolled triethylsilane promoted reduction of the resulting cyclic amidols.
Enaminones in heterocyclic synthesis: A new regioselective synthesis of 2,3,6‐trisubstituted pyridines, 6‐substituted‐3‐aroylpyridines and 1,3,5‐triaroylbenzenes
Authors: Al‐Saleh Balkis , Abdelkhalik Mervat Mohammed , Eltoukhy Afaf Mohammed , Elnagdi Mohammed Hilmy 
Published: March 2009

Abstract1‐Substituted‐3‐dimethylaminopropenones 1a‐d reacted with acetylacetone and with ethyl acetoacetate to yield regioselectively 2,3,6‐trisubstituted pyridines. Refluxing 1a‐d in acetic acid/ammonium acetate resulted in the formation of 6‐substituted‐3‐aroylpyridines, whereas refluxing in acetic acid alone afforded 1,3,5‐triaroylbenzene.
Synthesis of zincic phthalocyanine derivative functionalized with four peripheral tetrathiafulvalene units
Authors: Hu Yingyu , Shen Yongjia 
Published: March 2009

AbstractA zincic phthalocyanine (Pc) derivative functionalized with four peripheral substituted tetrathiafulvalene (TTF) units has been synthesized. The intermediates and target compound have been characterized by 1H‐nmr, 13C‐nmr, ms, EA, uv‐vis and mp. The molecular weight of H2Pc‐TTF4 can not be found in mass spectra. 1H‐nmr spectra and mp determination show both H2PC‐TTF4 and ZnPc‐TTF4 are isomer‐mixtures. Uv‐vis spectra indicate that the aggregation of H2PC‐TTF4 is solvent dependent and the introduction of Zn atom affects the solubility of the assembly.
Ultrasonic irradiation of the ullmann condensation: Application to the preparation of dioxolo, dioxino, cyclopent, and imidazolo anthranilic acid derivatives
Authors: Robin Maxime , Pique Valérie , Faure Robert , Galy Jean‐Pierre 
Published: March 2009

AbstractThe synthesis of N‐aryl anthranilic acid derivatives bearing dioxolo, dioxino, cyclopent, and imidazolo supplementary ring systems is reported. The Ullmann‐Goldberg condensation of the N‐aryl anthranilic acid is improved in yield and reaction time, compared to conventional heating; by ultrasonic irradiation.
Synthesis and biological evaluation of 9‐thia‐5,10‐dideazafolic acid
Authors: Wall Mark , Benkovic Stephen J. 
Published: March 2009

AbstractThe folate analogue, 9‐thia‐5,10‐dideazafolic acid (3b), was obtained in an efficient two‐step procedure in an overall yield of 60%. The previously unknown intermediate dimethyl‐thiocarbamic acid S‐(2‐amino‐3,4‐dihydo‐4‐oxo‐pyrido[2,3‐d]pyrimidin‐6‐yl) ester (5) was prepared via the condensation of 2,6‐diamino‐3H‐pyrimidin‐4‐one and S‐(2‐malonaldehyde)‐1,1,3,3‐tetramethylthiouronium bromide (4). Compound 5, in a one pot procedure, was deprotected using sodium hydroxide and then coupled to diethyl N‐[(4‐chloromethyl)benzoyl]‐L‐glutamate, followed by saponification of the ethyl esters to give the 9‐thia‐5,10‐dideazafolic acid (3b). Compound 3b was a potent inhibitor of human 5‐aminoimidazole‐4‐carboxamide ribonucleotide transformylase (Ki of 8 ± 5 μM) and showed no inhibition of human glycinamide ribonu‐cleotide transformylase at concentrations as high as 50 μM. Compound 3b was screened by the National Cancer Institute Developmental Therapeutics Program against 60 human tumors and was found to be active against a leukemia RPMI‐8226 cell line where the LC50 was 1 μM.
A convenient method for the preparation of highly substituted pyrimidines: Synthesis of tri‐ and tetra‐subsituted pyrimidines from 1,3‐dicarbonyl compounds and N,N,N‐tris‐(trimethylsilyl)amidines
Authors: Ghosh Usha , Katzenellenbogen John A. 
Published: March 2009

AbstractA modification of the Pinner pyrimidine synthesis has been developed that utilizes trimethylsilyl amidines and results in greatly improved yield of highly substituted pyrimidines.
Preparation of substituted 1,3‐dihydro‐2H‐imidazo[4,5‐c]pyridin‐2‐ones
Authors: Bakke Jan M. , Gautun Hanna S. H. , Svensen Harald 
Published: March 2009

AbstractA new synthetic route to 6‐substituted‐imidazo[4,5‐c]pyridin‐2‐ons from 4‐aminopyridine has been investigated. 4‐Aminopyridine protected as alkyl carbamates were nitrated with dinitrogen pentoxide to the corresponding methyl, i‐propyl and t‐butyl 3‐nitropyridin‐4‐yl carbamates (5a‐c) in 51‐63 % yields. Attempts to substitute these in the 6‐position by the ONSH and the VNS techniques succeeded with butyl‐amine and the t‐butyl carbamate 9. From the methyl or t‐butyl 3‐nitropyridin‐4‐yl carbamates 5a, 5c 1,3‐dihydro‐2H‐imidazo[4,5‐c]pyridin‐2‐one (1) was formed in 73 and 39 % yields, respectively. t‐Butyl 6‐N‐butylamin‐3‐aminopyridin‐4‐yl carbamate (6) gave 6‐butylamino‐1,3‐dihydro‐2H‐imidazo[4,5‐c]‐pyridin‐2‐one (7) in 53 % yield.
Synthesis of (+/‐) mappicine and mappicine ketone
Authors: Henegar Kevin E. , Baughman Ted A. 
Published: March 2009

AbstractMappicine and mappicine ketone are camptothecin analogs of interest as antiviral agents. A novel synthesis of these compounds is described using a Friedlander condensation. The requisite ketone is prepared via a regioselective ortho‐directed metallation/alkylation of a trisubstituted pyridine. This is condensed with N‐t‐butyloxycarbonyl‐o‐aminobenzaldehyde as a convenient, stable o‐aminobenzaldehyde equivalent in the Friedlander condensation.
1,2,3‐ and 1,2,4‐triazolium salts, pyrazoles, and quinoxalines from diarylnitrilimines and isocyanides: A study of the scope
Authors: Moderhack Dietrich , Daoud Ali 
Published: March 2009

AbstractFormation of the four title compounds has been found to be strongly dependent on substituents: 1,2,3‐Triazolium salts 6 do not arise from nitrilimines 2 that have an electron‐acceptor attached to either the C‐ or the N‐phenyl group. Likewise tert‐butyl and aryl isocyanides do not afford this class of compounds; from the former isocyanide, dequaternization products 7 are obtained instead, whereas from the latter 1,2,4‐triazolium salts 11 are formed. Compounds 11 with tert‐butyl group at the ring are unstable too, giving rise to triazoles 13. Pyrazole formation (analogues of 14) is completely suppressed when both tert‐butyl and aryl isocyanides are used, whereas access to this ring system works best with see‐alkyl isocyanides (the influence of substituents of 2 being almost negligible in this case). Formation of quinoxalines 23 which arise from intermediary 1,2‐diazets 22 by ring expansion is much favoured on employment of 2 that bears a donator substituent at the N‐phenyl group, and under this premise ring closure to 22 is virtually independent on the nature of the isocyanide. Formation of 23 is not observed with 2 having acceptor groups.
The effect of intramolecular‐hydrogen bonds in the synthesis of novel imidates from a 13‐membered dioxadithia crown ether diester
Authors: Karaböcek Serdar , Degirmencioglu Ismail , Karaböcek Nevin , Er Mustafa , Serbest Kerim 
Published: March 2009

AbstractThe synthesis and structural properties of three novel imidates, 11,13‐bis‐(2‐amino‐ethylimino)‐1,10‐dioxa‐4,7‐dithiacyclotridecane (2), 11,13‐bis‐(3‐aminopropylimino)‐1,10‐dioxa‐4,7‐dithiacyclotridecane, (3) and 2,11‐dioxa‐5,8‐dithia‐13,16,19,22‐tetraazabicyclo[10.10.1]tricosa‐1(22),12‐diene, (4) have been described. These compounds were synthesized by treating 1,10‐dioxa‐4,7‐dithiacyclotridecane‐11,13‐diester (1) with the appropriate diamine under N2 and their structures have been characterised by elemental analyses, 1H‐ and 13C‐nmr, ir, and mass spectral studies. Elemental analyses and spectroscopic data support the proposed imidate structures. In addition, total energy and heat of formation (Figure 2) calculated for imidates 2a‐4a and 2b‐4b by the semiempirical AM1 calculations have shown that imidates 2b‐4b having intramolecular hydrogen bonds are more stable (5‐10 kcal/mol) than compounds 2a‐4a.
Novel ‘quinolone’ metal complexes: Synthesis and spectroscopic studies of mg(II), zn(II) and ba(II) complexes with N‐methyl (or NH)‐3‐acetyl‐4‐hydroxy quinolin‐2‐one ligands
Authors: Athanasellis Giorgos , Gavrielatos Efstathios , Igglessi‐Markopoulou Olga , Markopoulos John 
Published: March 2009

AbstractThe complexation between N‐methyl‐3‐acetyl‐4‐hydroxyquinolin‐2‐one (NMeQuin) and N‐H‐3‐acetyl‐4‐hydroxy quinolin‐2‐one (NHQuin) with MgCl2, ZnCl2 and BaCl2 has been accomplished. The structure of the resulting complexes 1–5 has been elucidated through elemental analyses, FT‐IR and 1H/13C NMR Spectroscopy and Mass Spectrometry. The spectroscopic data show complexes of the general formula Mg2(OH)L3(H2O)z and ML2(H2O)Z where: M = Zn(II) and Ba(II), L = NMeQuin, NHQuin and z = 2, 4.
2‐(4‐methylpyridin‐2‐yl)‐1H‐benzimidazole derivatives. Part II, lH nmr characterization
Authors: Barni Ermanno , Barolo Claudia , Quagliotto Pierluigi , Savarino Piero , Viscardi Guido , Marabello Domenica 
Published: March 2009

AbstractA selected series of 2‐(4‐methylpyridin‐2‐yl)‐1H‐benzimidazole derivatives, bases and cyclic mono‐ and bis‐salts, were synthesized. Complete '1H nmr characterization is reported. Ambiguous assignments were solved using 1H‐1H NOESY analysis. Significant ir and 1H nmr data are presented concerning: i) tautomeric equilibrium of imidazole hydrogen; ii) hydrogen bonds; iii) conformational inversion of partially saturated rings.
Synthesis of 3‐Ω‐amino‐2‐thiohydantoins
Authors: Ryczek Józef 
Published: March 2009

AbstractIn the reaction of ethyl isothiocyanatoacetate with diamines, followed by cyclization of the intermediate product, 3‐monosubstituted thiohydantoins have been obtained. It was found that the reaction course depends on the purity of the isothiocyanate used and also, in the case of dialkylaminoamines, the self‐cyclization occurs. Besides the dialkylamino derivatives of 3‐monosubstituted 2‐thiohydantoins also new monoalkylamino, amino and heterocyclic derivatives were synthesized. The aryldiazonium derivative of 3‐monosubstituted 2‐thiohydantoin yielded both respective phenol derivative after hydrolysis and the product of coupling with 2‐naphthol.
Nickel boride mediated reductive desulfurization of 2‐thioxo‐4(3H)‐quinazolinones: A new synthesis of quinazolin‐4(3H)‐ones and 2,3‐dihydro‐4(1H)‐quinazolinones
Authors: Khurana Jitender M. , Kukreja Gagan 
Published: March 2009

AbstractA novel one‐pot approach for the synthesis of aryl substituted quinazolin‐4(3H)‐ones and 2,3‐dihydro‐4(1H)‐quinazolinones has been reported based on the reductive desulfurization of 3‐aryl‐2‐thioxo‐4(3H)‐quinazolinones with nickel boride in dry methanol at ambient temperature.