bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitroimidazoles. XII. A simple and efficient synthesis of 1‐methyl‐5‐nitroimidazole‐2‐acetic acid
Authors: Moezzi A. M. , Ghanbarpour A. , Shafiee A. 
Published: March 2009

AbstractReaction of 1‐methyl‐5‐nitroimidazole‐2‐carboxyl chloride (9) with diazomethane afforded 2‐diazo‐1‐(1‐memyl‐5‐nitro‐2‐imidazolyl)ethanone (10). Successive rearrangement of compound 10 via Arndt‐Eastert rearrangement yielded 1‐memyl‐5‐mtroimidazole‐2‐acetic acid (1), which was converted to its corresponding methyl ester 11 with etheral solution of diazomethane.
Synthesis of new proton‐ionizable dibenzocrown ethers
Authors: Kim Jong Seung , Bartsch Richard A. 
Published: March 2009

AbstractA series of structurally related dibenzo‐15‐crown‐5, dibenzo‐18‐crown‐6, and dibenzo‐21‐crown‐7 compounds with oxymethylacetoxy side arms is synthesized by reaction of the corresponding crown ether alcohols with potassium hydride and bromoacetic acid. Multi‐step synthetic routes to the crown ether alcohol precursors are reported.
Reaction of 5‐amino‐1‐aryl‐3‐methylpyrazoles with benzylidene derivatives of meldrum's acid: Synthesis and characterization of pyrazolo[3,4‐b]pyridinones
Authors: Quiroga Jairo , Hormaza Angelina , Insuasty Braulio , Márquez Manuel 
Published: March 2009

AbstractA series of dihydropyrazolo[3,4‐b]pyridin‐6‐ones 3 was prepared by cyclization of 5‐amino‐1‐aryl‐3‐methylpyrazoles 1 and Meldrum's acid benzylidene derivatives 2 in nitrobenzene. The structure of 4,5‐dihydropyrazolo[3,4‐b]pyridin‐6‐ones and reaction orientation were determined by nmr measurements.
The synthesis of hexahydrooxoepithiopyridinedicarboximides by the reaction of thioamides with N‐substituted maleimides
Authors: Takido Toshio , Tamura Sachiko , Sato Kenji , Kamijo Haruo , Nakazawa Toshikatsu , Seno Manabu , Hata Tadashi 
Published: March 2009

AbstractThe synthesis of hexahydrooxoepithiopyridinedicarboxyimide (5: X2 = N‐Ph) by the reaction of thioamides 1 with N‐substituted maleimide (2a) was examined. The reaction of primary thioamides, such as thiobenzamide and p‐toluthioamide with N‐phenylmaleimide gives compounds 5 together with corresponding 4‐hydroxy‐1,3‐thiazoles 4. However, a similar reaction of secondary thioamides, such as N‐methylthioacetamide, thiobenzanilide, with N‐phenylmaleimide did not provide compounds 5 without addition of acid. The reaction pathway and the configuration of 5 were also investigated.
Synthesis of 4‐aryl‐4,7,8,9‐tetrahydro‐6H‐pyrazolo[3,4‐b]quinolin‐5‐ones
Authors: Quiroga Jairo , Insuasty Braulio , Hormaza Angelina , Saitz Claudio , Jullian Carolina 
Published: March 2009

AbstractReaction of 5‐amino‐3‐methyl‐1‐phenylpyrazole (1a) and 5‐amino‐3‐(4‐chlorophenyl)‐1H‐pyrazole (1b) with dimedone (2) and p‐susbstituted benzaldehydes 3 in ethanol, afforded in all cases tricyclic linear 4‐aryl‐7,7‐dimethyl‐4,7,8,9‐tetrahydro‐6H‐pyrazolo[3,4‐b]quinolin‐5‐ones (4a‐j) in good yields. The linear structures and hence the regiospecificity of the reaction were established by nmr measurements.
Synthesis of some substituted dibenzodiazepinones and pyridobenzodiazepinones
Authors: Cohen Victor I. , Jin Biyun , Cohen Emil I. , Zeeberg Barry R. , Reba Richard C. 
Published: March 2009

AbstractSome fluoro‐ and iodo‐derivative of 5‐[[4‐[(4‐diisobutylamino)butyl]‐1‐phenyl]acetyl]‐10,11‐dihydro‐5H‐dibenzo[b,e][1,4]diazepin‐1l‐one and 11‐[[4‐[(dialkylamino)butyl]‐1‐phenyl]acetyl]‐5,11‐dihydro‐6H‐pyrido[2,3‐b][1,4]benzodiazepin‐6‐ones 6 (Scheme 1) and their analogues were synthesized. The synthesis of dibenzodiazepinones 1 (Scheme 1) is based on the reaction between 1,4‐phenylenediamine and substituted benzoic acids. The intermediate pyridobenzodiazepinones 3 (Scheme 1) were prepared by condensation of 2‐chloro‐3‐aminopyridine with methyl anthranilate and its chlorine derivative. The condensation of 4‐[(halo)alkyl]phenylacetyl chloride with dibenzodiazepinones and pyridobenzodiazepinones followed by the reaction of mono‐ or dialkyl‐ or dialkenylamine provides 6 (Scheme 1).
New lariat ether carboxylic and hydroxamic acids: Synthesis and lanthanide ion complexation
Authors: Elshani Sadik , Noriyuki Randal , Wai Chien M. , Natale N. R. , Bartsch Richard A. 
Published: March 2009

AbstractTwenty‐six new lariat ether carboxylic and hydroxamic acids based upon dibenzo‐13‐crown‐4, dibenzo‐14‐crown‐4, dibenzo‐16‐crown‐5 and dibenzo‐19‐crown‐6 ring systems are synthesized and the solid‐state structure for a dibenzo‐19‐crown‐6 lariat ether hydroxamic acid is determined. The efficiency and selectivity for lanthanide ion extraction into chloroform by these proton‐ionizable lariat ethers is strongly influenced by the crown ether ring size, lipophilic group attachment site and identity of the acidic function. In general, the lariat ether hydroxamic acids were more efficient and selective lanthanide ion extractants than the corresponding lariat ether carboxylic acids. The 1H nmr and ir binding studies indicate that both the macrocyclic polyether unit and the proton‐ionizable group are involved in lanthanide ion complexation.
Synthesis of novel 5‐aryl‐6‐cyano‐3H,8H‐pyrido[2,3‐d]pyrimidine‐4,7‐diones in the reaction of 6‐amino‐4‐pyrimidinones with benzaldehyde and ethyl cyanoacetate
Authors: Quiroga Jairo , Alvarado Mario , Insuasty Braulio , Nogueras Manuel , Sánchez Adolfo , López M. Dolores 
Published: March 2009

AbstractThe title compounds 4 and 5 have been prepared in one‐step reaction from 6‐amino‐4‐pyrimidinones 1, the corresponding 4‐substituted benzaldehyde 2 and ethyl cyanoacetate 3 in very good yields. The structure of the final compounds was determined on the basis of nmr measurements, especially by 1H, 1H‐, 1H,13C COSY, and DEPT.
Cyclecondensation of 3‐amino‐1,2,4‐triazole with substituted methyl cinnamates
Authors: Desenko Sergey M. , Lipson Victoria V. , Shishkin Oleg V. , Komykhov Sergey A. , Orlov Valery D. , Lakin Evgeny E. , Kuznetsov Valery P. , Meier Herbert 
Published: March 2009

AbstractThe reaction of 3‐amino‐1,2,4‐triazole (1) with substituted methyl cinnamates2a‐hleads selectively to the formation of 7‐aryl‐6,7‐dihydro[1,2,4]triazolo[1,5‐a]pyrimidin‐5(4H)‐ones3a‐h. The structure eluci dation of the products is based on ir,1H and13C nmr measurements and X‐ray diffraction.
Arylidene imidazothiazoles. Synthesis, structure and benzodiazepine receptor binding
Authors: Kieć‐Kononowicz Katarzyna , Szymańska Ewa , Karolak‐Wojciechowska Janina , Ksiazek Waldemar , Müller Christa E. , Geis Uli 
Published: March 2009

AbstractA series of arylidene imidazo[2,1‐b]thiazoles was synthesized, in order to investigate the influence of different spatial arrangements of the arylidene substituent towards the bicyclic structure of imidazo[2,1‐b]‐thiazole on benzodiazepine receptor affinity. 1,2‐ And 2,3‐cyclized derivatives ofmono‐ anddi‐substituted Z‐5‐arylidene‐2‐thiohydantoins were investigated. As an example ofEisomersE‐5‐benzylidene‐2,3‐dihydroimidazo[2,1‐b]thiazol‐6(5H)‐one was obtained. The spatial arrangement of the arylidene sub stituent toward the bicyclic structure as well as the character of isomers had little influence on the benzo diazepine receptor affinity of the compounds. It seems that the greatest influence on biological activity has the nature and the number of substituents on the phenyl ring. All investigated imidazo[2,1‐b]thiazoles were less active than previously described arylidene imidazo[2,1‐b]thiazepinones.
Synthesis of a chiral macrocyclic dibenzodicyclohexanotetraamide‐containing stationary phase for liquid chromatography
Authors: Hu Kejiang , Bradshaw Jerald S. , Dalley N. Kent , Krakowiak Krzysztof E. , Wu Naijun , Lee Milton L. 
Published: March 2009

AbstractAllyloxy‐substituted macrocyclic dibenzodicyclohexanotetraamide 2 was prepared by the following sequence. MonoBoc‐protected chiral 1,2‐cyclohexanediamine (3) was treated with isophthaloyl chloride followed by removal of the Boc group to form bisisophthalamide 5. Compound 5 was then treated with allyloxyphthaloyl chloride to form the macrocyclic tetraamide 2 in a 56% yield. Chiral selector 2 was converted to its ethoxydimethylsilane derivative and heated in a suspension of silica gel and toluene to form the chiral macrocycle‐containing silica gel phase 1. This phase separated the enantiomers of (±)‐α‐methylbenzylamine and (±)‐DL‐α‐aminobutyric acid methyl ester in a liquid chromatograph.
General preparative route to benzo[g]quinolines (1‐azaanthracenes)
Authors: Krapcho A. Paul , Gilmor Timothy P. 
Published: March 2009

AbstractA convenient synthetic pathway to benzo[g]quinolines (1‐azaanthracenes) has been developed. The nickel catalyzed coupling of methyl 2‐chloronicotinate (3a) with benzylic organo zinc reagents 2a‐e led to the methyl 2‐benzylic substituted nicotinates 4a‐e. Treatment of methyl 2‐chloro‐6‐methylnicotinate (3b)with 2a in a similar manner led to methyl 2‐benzyl‐6‐methyInicotinate (4f). The coupling of 2‐chloro‐3‐acetylpyridine (5) with benzyl zinc bromide (2a) led to 2‐benzyl‐3‐acetylpyridine (4g). The coupling of the 2,5‐dichlorobenzylic organic zinc reagent (2f) with methyl 2‐choronicotinate (3a) was unselective but readily coupled with methyl 2‐bromonicotinate (6) to yield methyl 2‐(2,5‐dichlorobenzyl)nicotinate (4h). The esters 4a‐f,h on reduction with lithium aluminum hydride led to the corresponding alcohols 7a‐f,h which were subsequently oxidized with manganese dioxide to the respective 2‐benzylic substituted pyridine‐3‐carboxaldehydes 8a‐f,h. In one case the coupling of benzy] zinc bromide (2a) with 2‐chloropyridine‐3‐carboxaldehyde (9) led directly to 2‐benzylpyridine‐3‐carboxaldehyde (8a), but in poor yield. Cyclizations of the aldehydes 8a‐d,f,h or the ketone 4g with polyphosphoric acid afforded the benzo[g]quinolines 10a‐d,f‐h in high yields. Aldehyde 8e was cyclized to 10e using a solution of sulfuric acid in methanol. Several of the benzo[g]quinolines 10c,d could be readly converted into the benzo[q]quinoline‐5,10‐diones 11c,d on treatment with ammonium ceric nitrate.
Dihydrothienopsoralens: New furocoumarins as potential photoreacting agents
Authors: Zoubir B. , Refouvelet B. , Xicluna A. , Aubin F. , Humbert P. 
Published: March 2009

AbstractA series of new dihydrothienopsoralen derivatives were synthesized from 6‐hydroxybenzo[b]furan in four steps in good yield. These compounds were prepared as potential photosensitizing and chemotherapeutic agents for psoriasis. The spectroscopy study in also reported and showed an absorbance at λ = 364 nm and fluorescence at λ = 440 nm with high molar absorptivity, wave length used to perform the photochemical and photobiological experiments.
A facile and convenient method for the preparation of macrocyclic diamides
Authors: Sharghi Hashem , Niknam Khodabakhsh , Massah Ahmad Reza 
Published: March 2009

AbstractA number of macrocyclic diamides have been synthesized from the reaction of a diacid dicarboxylic dichloride with primary diamino compound in the presence of magnesium oxide‐silica gel at room temperature in good yields. Using urea and thiourea as well as diamines to produce the corresponding macrocycles in the range of 52–56% yields are also included in this paper. One of the major advantages of this method is simple regeneration of inorganic solid and its reuse through several cycles without a decrease in activity.
Synthesis and reactions of fluoroaryl substituted 2‐amino‐3‐cyanopyrroles and pyrrolo[2,3‐d]pyrimidines
Authors: Dave Chaitanya G. , Desai Nirmal D. 
Published: March 2009

AbstractSome fluoroaryl substituted 2‐amino‐3‐cyanopyrroles 2 were synthesized from the reaction between (2‐bromo‐1‐arylalkylidene)propanedinitriles 1 and fluoroaryl substituted aromatic amines under Gewald reaction condition, which on reaction with formamide and formic acid gave 4‐aminopyrrolo[2,3‐d]pyrimidines 3 and pyrrolo[2,3‐d]‐pyrimidin‐4(3H)‐ones 4 respectively. 4‐Chloropyrrolo[2,3‐d]pyrimidines 5 were prepared by chlorination of 4 with phosphorus oxychloride, which on hydrazinolysis provided 4‐hydrazinopyrrolo[2–3‐d]pyrirnidines 6.
Reaction of E‐2‐arylidene‐1‐indanones, Z‐aurones, Z‐1‐thioaurones and Z‐2‐arylidene‐2,3‐dihydro‐1H‐indol‐3‐ones with diazomethane
Authors: Lévai Albert , Patonay Tamás 
Published: March 2009

Abstract1,3‐Dipolar cycloaddition of E‐2‐arylidene‐1‐indanones 1a‐h and Z‐aurones 3a‐c with diazomethane provided trans‐spiro‐1‐pyrazolines 2a‐h and 4a‐c, respectively, as sole products. However, the same cycloaddition of Z‐1‐thioaurones 5a‐f afforded a mixture of Z‐α‐methyl‐1‐thioaurones 6a‐f and trans‐cyclopropane derivatives 7a‐f as a result of the spontaneous denitrogenation of the initially formed 1‐pyrazolines. Similar reaction of Z‐2‐arylidene‐2,3‐dihydro‐1H‐indol‐3‐ones 8a,b and diazomethane yielded trans‐cyclopropanes 9a,b. Structure and stereochemistry of the compounds synthesized have been elucidated by nmr spectroscopic measurements.
A new rigid benzene‐bridged macrotricyclic ligand
Authors: Krakowiak Krzysztof E. , Xue Guoping , Bradshaw Jerald S. , Dalley N. Kent , Nazarenko Alexander Y. , Zhang Xian X. , Izatt Reed M. 
Published: March 2009

AbstractA macrotricyclic ligand composed of two benzene rings connected by four 2,2′‐oxydiphenoxide bridges (2) has been prepared by treating 1,2,4,5‐tetrakis[2‐(2‐hydroxyphenoxy)phenoxymethyl]benzene with 1,2,4,5‐tetrakis(bromomethyl)benzene in acetonitrile in the presence of potassium carbonate. Ligand 2 is of interest because of its similarity to macrocycle 1 which interacts strongly with cesium ions. The proposed more direct route of treating an excess of 2,2′‐oxydiphenol with 1,2,4,5‐tetrakis(bromomethyl)benzene to prepare 2 did not give the desired macrocycle but gave bis(tribenzo‐11‐crown‐3) (8). An X‐ray crystal structure study of 2 showed that the benzene rings which are linked by the four 2,2′‐oxydiphenoxide bridges are connected in a nonsymmetric pattern. The structure of 8 was also determined using X‐ray diffraction methods, and is reported.
Synthesis and structural study of novel 1,4,5,6,7,8‐hexahydroquinolines
Authors: Suárez Margarita , Verdecia Yamila , Ochoa Estael , Martín Nazario , Martínez Roberto , Quinteir Margarita , Seoane Carlos , Soto José L. , Novoa Héctor , Blaton Norbert , Peeters Oswald M. , De Ranter Camiel 
Published: March 2009

AbstractA new series of 1,4,5,6,7,8‐hexahydroquinolines (9a‐j) has been synthesized and their structural features studied by X‐ray analysis and theoretical calculations at semiempirical and ab initio levels. A good correlation is found between the most stable conformation predicted for compounds 9 and that obtained by experimental X‐ray diffraction for 9h. The obtained geometrical features for 9 are similar to those found for other related active calcium modulators.
The birch reduction of heterocyclic compounds V Birch reduction of 2‐ and 5‐acylfuran‐3‐carboxylic acids and reductive elimination of 2‐(arylmethoxymethyl)furan‐3‐carboxylic acids
Authors: Ohta Yasuo , Doe Matsumi , Morimoto Yoshiki , Kinoshita Takamasa 
Published: March 2009

AbstractThe Birch reduction of 2‐ and 5‐acylfuran‐3‐carboxylic acid 1 and 4 gave 2‐acyl‐2,3‐dihydrofuran‐3‐carboxylic acid 2 and 5‐acyltetrahydrofuran‐3‐carboxylic acid 5, respectively. Further examination of the reductive elimination was also studied on 2‐(arylmethoxymethyl)furan‐3‐carboxylic acids 7.
Synthesis of isomeric triazolopyrrolopyrimidines
Authors: Dave Chaitanya G. , Shah Rina D. 
Published: March 2009

Abstract4‐Hydrazino‐7H‐pyrrolo[2,3‐d]pyrimidines (4) were cyclocondensed with formic acid or triethyl orthoformate to give 7H‐1,2,4‐triazolo[1,5‐c]pyrrolo[3,2‐e]pyrimidines (5) and 7H‐1,2,4‐triazolo[4,3‐c]pyrrolo‐[3,2‐e]pyrimidines (6) respectively. The [4,3‐c]‐isomers (6) were rearranged into thermodynamically more stable [1,5‐c]‐isomers (5). The identical compounds (5) were prepared using another route by reacting 3‐amino‐4‐imino‐7H‐pyrrolo[2,3‐d]pyrimidines (3) with formic acid or triethylorthoformate. Reaction of 2‐amino‐3‐cyanopyrroles (1) with triethyl orthoformate followed by hydrazinolysis afforded (3) via the formation of N‐ethoxymethylene‐2‐amino‐3‐cyanopyrroles (2).
A comparative study of conventional conditions versus microwave irradiation for the preparation of novel 1,2‐dihydro‐2‐imino‐7‐methyl‐1,6(6H)‐naphthyridin‐5‐ones
Authors: Heber Dieter , Stoyanov Edmont V. 
Published: March 2009

AbstractThe synthesis of novel 1,6‐naphthyridines 6 with potential activity against tuberculosis is described using the reaction sequence 2←4←6. Depending on the ring N‐substitution of the 4‐alkylamino‐6‐methyl‐2(1H)‐pyridones 1 and 2 the electrophilic attack of the Vilsmeier reagent gives rise to the formation of the exocyclic N‐formyl derivatives 3 from 1 and the corresponding 3‐carbaldehydes 4 from 2. 1,2‐Dihydro‐2‐imino‐7‐methyl‐1,6(6H)‐naphthyridin‐5‐ones 6a‐j are prepared by the Knoevenagel reaction of 4 with CH‐acidic nitriles 5. These reactions are carried out using a comparative study of conventional conditions (room temperature or reflux) versus microwave irradiation.
A new route to functionalized 3‐aminopyridazines by ANRORC type ring transformation of 1,2,4‐triazines with carbon nucleophiles
Authors: Rykowski Andrzej , Wolinska Ewa , Van Der Plas Henk C. 
Published: March 2009

AbstractThe reaction of 3‐chloro‐6‐phenyl‐1,2,4‐triazine 1a with carbon nucleophiles 2ad bearing a cyano substituent at a carbanionic center has been studied. In all reactions the formation of the corresponding 3‐aminopyridazines 3ad takes place via ANRORC mechanism involving addition of the nucleophile at position 5 in compound 1a, ring opening with breaking of the N4C5 bond and intramolecular ring closure of the resulting open‐chain intermediate. A 15N study with labeled phenylacetonitrile 2a* has shown that the nitrogen atom of the exocyclic amino group of 3‐amino‐4,6‐diphenylpyridazine 3a was originally present in phenylacetonitrile.
Synthesis of derivatives of thiophene using methyl 2‐isothiocyanatobenzoate
Authors: Deck L. M. , Turner S. D. , Deck J. A. , Papadopoulos E. P. 
Published: March 2009

AbstractA variety of 2‐substituted thiophenes is readily obtained from 2‐(2‐thienyl)‐4H‐3,l‐benzothiazin‐4‐one (2), which is formed when thiophene reacts with methyl 2‐isothiocyanatobenzoate (1) in the presence of anhydrous stannic chloride.
Synthesis of 5‐(functionalized acyl)‐1,3‐dialkyl‐substituted barbituric and 2‐thiobarbituric acids
Authors: Zoorob Hanafi H. , Ismail Mohamed A. , Strekowski Lucjan 
Published: March 2009

AbstractA sodium derivative of 1,3‐dimefhylbarbituric acid or 1,3‐diethyl‐2‐thiobarbituric acid undergoes an efficient monoacylation at C5 by the reaction with ω‐chloroalkanoyl chloride or diacid dichloride in the presence of pyridine in tetrahydrofuran. A nucleophilic displacement of the chlorine in a 5‐chloroacetyl‐bartiburate can be accomplished by using a one‐pot procedure. By contrast, a similar transformation of a 5‐(chlorobutanoyl)barbituric acid requires intramolecular cyclization in the presence of a nonnucleophilic base followed by treatment with a nucleophile of the resultant 5‐[4,5‐dihydro(3H)‐2‐furylidene]barbiturate.
Inverse electron‐demand 1,3‐dipolar cycloaddition reactions of cyclooctyne with pyridinium bis(methoxycarbonyl)methylides
Authors: Matsumoto Kiyoshi , Hayashi Naoto , Ikemi Yukio , Toda Mitsuo , Uchida Takane , Aoyama Kinuyo , Miyakoshi Yoshihiro 
Published: March 2009

AbstractCyclooctyne underwent 1,3‐dipolar cycloaddition with pyridinium bis(methoxy‐carbonyl)methylides to afford the corresponding indolizines (8‐methoxycarbonyl‐7‐azatricyclo[7.6.0.02‐7]pentadeca‐1,3,5,8‐tetraenes) in good to moderate yields. Some molecular orbital considerations are also described on this reaction compared with the results on the reaction of pyridinium dicyanomethylides with cyclooctyne.
Synthesis of novel alkylamino zinc(II) phthalocyanines
Authors: Rodríguez Myriam E. , Strassert Cristian A. , Awruch Josefina , Dicelio Lelia E. 
Published: March 2009

AbstractThe synthesis of tetramethyl‐tetraphthalimidomethyl‐phthalocyaninato zinc(II) (6) and tetramethyl‐tetraaminomethyl‐phthalocyaninato zinc(II) (7) is described.
Reactions of 1‐amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one with carboxylic anhydrides: Experimental data and AM1 calculations
Authors: Önal Zülbiye , Sanpinar Emin , İlhan Ilhan Özer 
Published: March 2009

Abstract1‐Amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one 1 reacts with several carboxylic anhydrides 2a‐d under different conditions and gives new amide and imide derivatives. The structure of these compounds, 3a‐d, are determined by spectroscopic methods. Electronic and geometric structures of reactants, transition states, intermediates and final products of the reaction are calculated by the AM1 method. Transition states are further confirmed by vibrational analysis (computation of force constants analytically) and characterized by the corresponding imaginary vibration modes and frequencies.
Polycyclic N‐Heterocyclic Compounds. 56 Reaction of N‐(5,6‐Dihydro[1]benzoxepino[5,4‐d]pyrimidin‐4‐yl)amidine or Its Amide Oxime Derivatives with Hydroxylamine Hyrdochloride
Authors: Sasaki Kenji , Zhang Ying‐Xue , Okuda Kensuke , Hirota Takashi 
Published: March 2009

AbstractThe reactions of N‐(5,6‐dihydro[1]benzoxepino[5,4‐ d]pyrimidin‐4‐yl)amidines or its amide oxime derivatives with hydroxylamine hydrochloride gave abnormal cyclization products via a ring cleavage of pyrimidine component accompanied with a ring closure of [1,2,4]oxadiazole.
Difurocoumarins: Psoralen analogs as photochemotherapeutic agents
Authors: Chilin A. , Manzini P. , Caffieri S. , Rodighiero P. , Guiotto A. 
Published: March 2009

AbstractNew tetracyclic psoralen‐like compounds have been synthesized, which are characterized by two furan rings angularly condensed on the coumarin nucleus and are therefore called difurocoumarins. This structural feature may favour the intercalation into the DNA helix and then monofunctionally photoreaction with DNA bases. Their synthesis started from 5,7‐dihydroxy‐4‐methylcoumarin, which was condensed with α‐halo‐ketones; the resulting ketoethers were then cyclized to give the title compounds.
Differentiation between 1,2,4,5‐tetraoxanes and 1,2,4,5,7,8‐hexaoxonanes using 1H and 13C NMR analyses
Authors: Dong Yuxiang , Vennerstrom Jonathan L. 
Published: March 2009

AbstractThe proton and carbon resonance spectra of ten pairs of 1,2,4,5‐tetraoxanes and 1,2,4,5,7,8‐hexa‐oxonanes derived from acyclic and cyclic ketones have been recorded. A reliable method for distinguishing between 1,2,4,5‐tetraoxanes and 1,2,4,5,7,8‐hexaoxonanes by inspection of their chemical shifts, signal number, signal shape, and dynamic features has been developed. This method provides a rapid structural assignment of 1,2,4,5‐tetraoxanes and 1,2,4,5,7,8‐hexaoxonanes without using vapor pressure osmometry, isotope labeling or low temperature NMR techniques.
Configurational assignments of the diastereomers of 3,3′‐(1,2‐ethanediyl)bis[2‐(3‐fluorophenyl)‐5‐methyl‐4‐thiazolidinone] derivative with four stereogenic centers
Authors: Vigorita Maria Gabriella , Ottaná Rosaria , Monforte Francesca , Previtera Tindara , Maccari Rosanna 
Published: March 2009

AbstractDiastereomers of antiinflammatory/analgesic and antihistaminic 3,3′[(1,2‐ethanediyl)bis(2‐aryl‐4‐thiazo‐lidinone)] derivatives possessing two stereogenic centers (indicated as BIS 2*C) have been widely investigated in recent years. The 5,5′‐dimethyl analogues (BIS 4*C), now reported, have been synthesized by reaction of (±) α‐mercaptopropionic acid and N,N'‐di(3‐fluorobenzyliden)ethylenediamine. Because the 2 and 2′carbons bear the same groups and similarly the 5 and 5′ carbons, and the latter groups are different from the former, four enantiomeric pairs and two meso forms exist in this situation. These diastereomers were identified by the concerted use of nmr spectroscopy and hplc on chiral stationary phase.