bluuebunny/crossref_metadata_2025 huggingface dataset:
Regio‐ and stereoselective synthesis of spiro[1‐benzothiepine‐4(5h), 3′(3h)‐pyrazol]‐5‐ones
Authors: Mishriky Nawal , Girgis Adel S. , Hosni Hanaa M. , Farag Hanaa
Published: March 2009

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Reaction of (4E)‐4‐arylmethylene‐3,4‐dihydro‐1‐benzothiepin‐5(2H)‐ones 3a‐e with nitrilimines (generated in situ via triethylamine dehydrohalogenation of the corresponding hydrazonoyl chlorides 4a, b) in refluxing benzene, afforded 2′,4′,5′‐triaryl‐2,2′,3,4′‐tetrahydro‐spiro[1‐benzothiepine‐4(5H),3′(3H)‐pyrazol]‐5‐ones 5a‐i and not the isomeric forms spiro[1‐benzothiepine‐4(5H),4′(4H)‐pyrazol]‐5‐ones 6 in high regioselective manner. Single crystal X‐ray diffraction studies of 5a, f, g indicated that the isolated products are 3′R, 4′ S.
Reactivity of (2‐methylsulfanyl‐4‐oxo‐6‐phenyl‐4h‐pyrimidin‐3‐yl)‐acetic acid methyl ester towards hydrazine hydrate and benzylamine
Authors: Burbuliene Milda M. , Dobrovolskaite Rita , Vainilavicius Povilas
Published: March 2009

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The title ester 1 reacted with hydrazine hydrate to give hydrazide 2, which underwent intramolecular cyclization to yield 1‐amino‐7‐phenyl‐1H‐imidazo[1,2‐a]pyrimidine‐2,5‐dione (3) or took place in a substitution reaction with benzylamine to form N‐benzyl‐2‐(2‐benzylamino‐4‐oxo‐6‐phenyl‐4H‐pyrimidin‐3‐yl)‐acetamide (4). The reaction of ester 1 with benzylamine gave corresponding amide 7, disubstituted derivative 4 or 1‐benzyl‐7‐phenyl‐1H‐imidazo[1,2‐a]pyrimidine‐2,5‐dione (8) depending on the reaction conditions.
Synthesis and tautomerization of 6,7‐dihydro‐(1,2,3)‐triazolo[1,5‐a]pyrimidines
Authors: Desenko Sergey M. , Gladkov Evgeny S. , Shishkina Svetlana V. , Shishkin Oleg V. , Komykhov Sergey A. , Orlov Valery D. , Meier Herbert
Published: March 2009

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The condensation of 5‐amino‐4‐phenyl‐1,2,3‐triazole (1) with chalcones 2a‐e or 3‐dimethylamino‐propiophenone (4f) leads to the 6,7‐dihydro‐(1,2,3)‐triazolo[1,5‐a]pyrimidines 3a‐f. The equilibrium of 3 and the tautomeric 4,7‐dihydro‐(1,2,3)‐triazolo[1,5‐a]pyrimidines 3′ is described.
Synthesis and e/z determination of substituted 2‐phenylimidazoles
Authors: Szotkowski ToméŠ , Bureš Filip , Pytela Oldǐich , Kulhének Jiǐí , Trévníček Zdeněk
Published: March 2009

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Nine new 4‐substituted 2‐phenylimidazole derivatives have been synthesized by aldol condensation of 2‐phenylimidazole‐4‐carbaldehyde with various active methylene compounds. In case of non‐symmetric active methylene compound used, the stereospecific formation of only one cis‐trans isomer has been observed. The predominant formation of products with bulkier substituents standing opposite on double bond formed by aldol condensation has been proved. cis‐trans Isomerism of three unsymmetrically substituted products has been determined by 1H coupled 13C NMR experiments. 3‐[(2‐Phenylimidazol‐4‐yl)methylene]pentane‐2,4‐dione has been characterized by single crystal X‐ray structural analysis as well. Selected bond lengths and angles have proved the expected large mesomerical stabilisation in the molecule. The hydrogen bond in crystal phase has been observed.
The synthesis of 3,3‐dimethyl‐2‐(1‐aryl‐1h‐pyrazol‐4‐yl)‐3h‐indoles
Authors: Baradarani Mehdi M. , Afghan Arash , Zebarjadi Farideh , Hasanzadeh Kamal , Joule John A.
Published: March 2009

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2,3,3‐Trimethylindolenine and 5‐chloro‐2,3,3‐trimethylindolenine were converted into β‐diformyl compounds by the action of the Vilsmeier reagent at 50°C. The dialdehydes reacted with various arylhydrazines and 2‐pyridylhydrazine to produce mono‐hydrazones as mixtures of cis and trans isomers. Heating the hydrazones in refluxing ethanol produced 3,3‐dimethyl‐2‐(1‐aryl‐1H‐pyrazol‐4‐yl)‐3H‐indoles in excellent yields. Reaction of the β‐diformyl compounds with hydrazine itself led directly to 3,3‐dimethyl‐2‐(pyrazol‐4‐yl)‐3H‐indoles.
Synthesis of the enantiomers of the dual function 2‐nitroimidazole radiation sensitizer RB 6145
Authors: Sercel Anthony D. , Beylin Vladimir G. , Marlatt Mark E. , Leja Boguslawa , Showalter H. D. Hollis , Michel André
Published: March 2009

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Short, efficient pathways are described for the synthesis of racemic 2‐nitroimidazole radiation sensitizer RB‐6145 (2a) and each of its corresponding (R)‐ and (S)‐enantiomers (2b and 2c, respectively). The synthesis of each enantiomer commences with the appropriate chiral epichlorohydrin and utilizes a novel application of 3‐trimethylsilyl‐2‐oxazolidinone (3b) as a mild, safe surrogate for highly toxic aziridine. The synthesis of the (R)‐enantiomer (2b) has been successfully scaled up to provide multi‐kilo quantities of material for early stage preclinical evaluation.
Microwave‐assisted “green” synthesis of 2‐alkyl/arylbenzothiazoles in one pot: A facile approach to anti‐tumor drugs
Authors: Kamila Sukanta , Koh Benjamin , Biehl Edward R.
Published: March 2009

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A series of new 2‐alkyl/arylbenzothiazoles has been synthesized on the basis of the potent and selective in vitro anti‐tumor properties of 2‐(3,4‐diethoxyphenyl)‐5‐fluorobenzothiazole. The synthesis of benzothiazole analogs was achieved via microwave irradiation of a 1:1 mixture of o‐aminothiophenol and alkyl/aryl acylacetonitriles at temperature of 200°C for 10 min. The yields are very good to excellent. All the products were characterized by 1H nmr, 13C nmr and elemental analysis.
Synthesis of 2‐phenylquinolin‐4‐amines substituted with diverse amino and aminoalkyl groups
Authors: Say Martial , Paliakov Ekaterina , Henary Maged , Strekowski Lucjan
Published: March 2009

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Facile synthetic approaches to 2‐phenylquinolin‐4‐amines containing an aminoalkyl group at N4 of the quinolin‐4‐amine and amino or aminoalkyl groups at the phenyl moiety are presented.
Synthesis of 2,4‐diaminothieno‐ and pyrrolo[2,3‐d]pyrimidine‐6‐carboxylic acid derivatives
Authors: Tumkevicius S. , Dailide M. , Kaminskas A.
Published: March 2009

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A series of new 2,4‐diaminothieno[2,3‐d]‐ and 2,4‐diaminopyrrolo[2,3‐d]pyrimidine derivatives were synthesised. Reaction of 2‐amino‐4,6‐dichloropyrimidine‐5‐carbaldehyde (1) with ethyl mercaptoacetate, methyl N‐methylglycinate or ethyl glycinate afforded ethyl (2‐amino‐4‐chloro‐5‐formylpyrimidin‐6‐yl)thioacetate (2a), methyl N‐(2‐amino‐4‐chloro‐5‐formylpyrimidin‐6‐yl)‐N‐methylglycinate (2b) and ethyl N‐(2‐amino‐4‐chloro‐5‐formylpyrimidin‐6‐yl)glycinate (2c), respectively. Compounds 2a,b by treatment with bases cyclised to the corresponding 2‐amino‐4‐chlorothieno‐ and pyrrolo[2,3‐d]pyrimidine‐6‐carboxylates (3a,b). Heating 2,4‐diamino‐6‐chloropyrimidine‐5‐carbaldehyde (5) with ethyl mercaptoacetate or methyl N‐methylglycinate gave 2,4‐diaminothieno[2,3‐d]‐ and 2,4‐diaminopyrrolo[2,3‐d]‐pyrimidine‐6‐carboxylates (6a,b), whereas compound 5 with ethyl glycinate under the same reaction conditions afforded ethyl N‐(2,4‐diamino‐5‐formylpyrimidin‐6‐yl)glycinate (7). Treatment of 2,4‐diaminothieno[2,3‐d]pyrimidine‐6‐carboxylic acid (8a) with 4‐methoxy‐, 3,4,5‐trimethoxyanilines or ethyl N‐(4‐aminobenzoyl)‐L‐glutamate in the presence of dicyclohexylcarbodiimide and 1‐hydroxybenzotriazole furnished the corresponding N‐arylamides 9‐11.
One pot synthesis of novel dispiro[oxindole‐thiazolidinedione/thioxo‐thiazolidinone/dihydro pyrazolone]‐pyrrolidines via 1,3‐dipolar cycloaddition reaction of azomethine ylides
Authors: Ponnala Shashikanth , Sahu Devi Prasad , Kumar Rishi , Maulik Prakas R.
Published: March 2009

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A series of novel dispiro[oxindole‐thiazolidinedione]pyrrolidine, dispiro[oxindole‐thioxothiazolidinone]‐pyrrolidine, dispiro[oxindole‐dihydro‐pyrazolone]pyrrolidine were synthesized by both regio‐ and stereo‐selective 1,3‐dipolar cycloaddition reaction of azomethine ylide generated from amino acid and amino acid ester with π‐deficient alkenes in a single pot protocol in good yield. X‐ ray crystallographic studies established orthogonal disposition between spiro‐oxindole and spiro‐thiazolidinedione rings in 4a and 5a.
Reactions of α‐diazoketones with indolinone imines: Synthesis of new 1,3,3‐triaryl‐1′‐methylspiro[azetidine‐2,3′‐indoline]‐2′,4‐diones
Authors: Singh Girija S. , Mmolotsi Boycie J.
Published: March 2009

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The paper describes the synthesis of new 1,3,3‐triary‐1′‐methylspiro[azetidine‐2,3′‐indoline]‐2′,4‐diones from reaction of the 2‐diazo‐1,2‐diarylethanones with 3‐arylimino‐1‐methyl‐2‐indolinones. The compounds have been characterized by satisfactory analytical and spectral (IR, 1H NMR and 13C NMR) data. The diarylketenes, generated in situ from thermal decomposition of the 2‐diazo‐1,2‐diarylethanones, react with azomethine linkage in preference to carbonyl group leading to the formation of products.
Synthesis of some new 4‐substituted‐3, 5‐bis(2‐pyridyl)‐1h‐pyrazole
Authors: Zhang Wei , Liu Jianhui , Jin Kun , Sun Licheng
Published: March 2009

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Several 4‐substituted‐3, 5‐bis(2‐pyridyl)‐1H‐pyrazoles, where the substituent is chloro, bromo, iodo, nitro, diazo, were synthesized under mild reaction conditions in high yields. The structures of the products were characterized by 1H NMR, 13C NMR, ESI‐MS, IR and elemental analyses.
Electrochemical oxidation of catechols in the presence of ethyl‐2‐chloroacetoacetate. Synthesis and mechanistic study
Authors: Shamsipur Mojtaba , Davarani Saied Saeed Hosseiny , Nematollahi Davood
Published: March 2009

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Electrochemical oxidation of catechol and some of 3‐substituted catechols (1a‐c) has been studied in the presence of ethyl‐2‐chloroacetoacetate (3) in water/acetonitrile (90:10) solution using cyclic voltammetry and controlled‐potential coulometry. The results indicate that the quinones derived from catechols (1a‐c) participate in Michael addition reactions with ethyl‐2‐chloroacetoacetate(3), with consumption of only two electrons per molecule of 1, to form the corresponding benzofurans (10a‐c). The electrochemical synthesis of benzofurans (10a‐c) has been successfully performed at a carbon rod electrode and in an undivided cell with good yields and purity. A new two‐electron mechanism for the electrode process is proposed.
Synthesis of new TTF‐anthracene dyads as potential fluorescence probe for 1O2
Authors: Liu Wei , Lu Jing‐Hua , Xu Ming , Zuo Jing‐Lin , You Xiao‐Zeng
Published: March 2009

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Three new fluorescence probes for 1O2 with different electron‐rich tetrathiafulvalene and anthracene units have been synthesized and characterized. Among them, compound 3c, 2,3‐bis[2‐(9‐anthryloxy) ethylthio]‐6,7‐(propylenedithio)‐1,4,5,8‐tetrathiafulvalene, is very sensitive and may act as the fluorescence probe for 1O2.
An efficient approach towards three component coupling of one pot reaction for synthesis of functionalized benzopyrans
Authors: Kumar B. Sunil , Srinivasulu N. , Udupi R. H. , Rajitha B. , Reddy Y. Thirupathi , Reddy P. Narsimha , Kumar P. S.
Published: March 2009

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Three component coupling of one pot reaction which servers as the most convenient route to the synthesis of benzopyran derivatives using the TiCl4 catalyst (10 mol %) under solvent free conditions is described. The procedure offers a systematic method with a number of advantages including operational simplicity, neat reactions, reduced reaction time, high yields of products and applicability to large scale reactions.
New synthesis, x‐ray structural determination, conformational analysis and anomeric effect study of 3,7‐di (3‐nitrophenyl)‐1,5‐dioxa‐3,7‐diazacyclooctane
Authors: Kakanejadifard A. , Mahmodi L. , Yari A. , Mohajeri A.
Published: March 2009

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3,7‐Di(3‐nitrophenyl)‐1,5‐dioxa‐3,7‐diazacyclooctane was prepared from 3‐nitroaniline and formaldehyde in acetonitrile. Conformational behavior of ring inversion of the molecule was studied so it prefers a crown conformation. The evaluated ΔG* was approximately 58.0 ± 1.0 kJ/mole. The X‐ray structure determination of the compound shows a crown conformation, in line with two‐anomeric effect in N‐C‐O moiety.
The [3 + 2] cycloaddition route to 5‐carbomethoxy‐4h‐1,2,3‐triazolo[1,5‐a][1]benzazepines from baylis‐hillman acetates of 2‐azidobenzaldehydes
Authors: Song Young Seok , Lee Kee‐Jung
Published: March 2009

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A new, simple synthesis of 5‐carbomethoxy‐4H‐1,2,3‐triazolo[1,5‐a][1]benzazepines from the reaction of several Baylis‐Hillman acetates of 2‐azidobenzaldehydes with alkynide Grignard reagents such as phenylethynyl‐, 1‐propynyl‐ and ethynylmagnesium bromides followed by cycloaddition reaction has been described.
A general synthesis of 8‐hydroxy‐6‐substituted‐1,7‐naphthyridines
Authors: Jiang Xinglong , Chen Guang‐Pei , Prasad Kapa , Repič Oljan , Blacklock Thomas J.
Published: March 2009

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A general method for the synthesis of 8‐hydroxy‐6‐substituted‐1,7‐naphthyridines is described using acylation of the dianion derived from tert‐butylamide 1, followed by cyclization of the resulting intermediate ketones 2 with ammonium acetate.
Azopyrazolobenzylidene derivatives of 4‐amino‐1,2,4‐triazol‐3‐ones. Synthesis of 4‐{[4‐(3,5‐dimethyl‐1H‐pyrazol‐4‐yl)diazenyl]‐benzylidene}amino‐2‐aryl‐5‐methyl‐3H‐[1,2,4]‐triazol‐3‐ones
Authors: Sunagar Vinay A. , Latthe Prashant R. , Badami Bharati V.
Published: March 2009

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The Schiff bases 3a‐h obtained from 4‐amino‐1,2,4‐triazol‐3‐ones 1a‐h when subjected to Japp‐Klingemann reaction yielded the corresponding 3‐{2‐[(2‐aryl‐5‐methyl‐3H‐[1,2,4]‐triazol‐3‐one‐4‐yl)]‐iminophenyl}‐pentane‐2,4‐diones 4a‐h. These diones on cyclisation with N2H4 yielded the title compounds 5a‐h. The energetics of the Keto‐enol tautomers of the diones was calculated by semiemperical calculations using AM1 and PM3 methods. All these compounds were screened for their antimicrobial activity against few microbes and most of them exhibited fungal inhibition more than the reference drugs used.
New routes to steroidal heterocyclic derivatives: Synthesis of biologically active pyrazolyl‐ and isoxazolylpregnene derivatives
Authors: Abdelhamid Abdou O. , Abdelhalim Mervat M. , Elmegeed Gamal A.
Published: March 2009

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Pyrazolyl‐ and isoxazolylpregnene derivatives were synthesized from the appropriate hydrazonoyl chlorides and hydroximoyl chlorides with enaminoprogesterone derivative. The newly synthesized compounds were elucidated by elemental analysis, spectral data and chemical transformation. Some products were tested towards some bacteria and some Fungal‐plant pathogens
Metathetic approach towards macrocyclic bis‐ethers and in sequence use of barbier reaction and RCM for spirocyclic ethers
Authors: Brahma Sulagna , Maity Susama , Ray Jayanta K.
Published: March 2009

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An efficient method for the synthesis of novel macrocyclic bis‐ethers from alizarin and also some new spiro ethers from various substituted ketones by the use of Barbier and ring‐closing metathesis (RCM) reactions has been developed.
A novel synthesis of some new benzoyl‐substituted heterocycles from 2‐benzoyl‐3‐phenylpent‐2‐ene‐1,5‐dinitrile
Authors: Abdelrazek Fathy M. , Ghozlan Said A. , Michael Farid A.
Published: March 2009

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2‐Benzoyl‐3‐phenylpent‐2‐ene‐1,5‐dinitrile 1 undergoes bromination with N‐bromosuccinimide (NBS) to afford the bromo derivative 2a. This bromo derivative undergoes reactions with sodium hydrogen sulfide, ethyl thioglycollate, hydroxylamine hydrochloride, hydrazines, cyanoacetamide, cyanacetohydrazide and urea derivatives to afford the thiophene 4, 4H‐thiopyran 6, 4H‐1,2‐oxazine 8, 4H‐pyridazines 10a,b, the pyridine 15, pyrrolo[1,2‐b]pyridazine 17 and the N‐substituted‐pyrrole derivatives 19a‐c respectively.
In situ preparation of rhodium/n‐heterocyclic carbene complexes and use for addition of arylboronic acids to aldehydes
Authors: Kilinçarslan Rafet , Çetinkaya Engin , Çetinkaya Bekir , Yiǧit Murat , Özdemir İsmail
Published: March 2009

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The in situ prepared three component system [RhCl(COD)]2/imidazolidinium salts (2, 4) and KOBut catalyses the addition of phenylboronic acid to sterically hindered aldehydes affording the corresponding arylated secondary alcohols in good yields. Four novel 1,3‐dialkylimidazolidinium (2‐4) salts as NHC precursors were synthesized from N,N′‐dialkylethylenediamine.
Syntheses and biological activities of novel triazole compounds
Authors: Zhang Shu‐Sheng , Wan Jun , Li Chun‐Li , Li Xue‐Mei , Qu Bin
Published: March 2009

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Fifteen novel compounds bearing the triazole moiety were synthesized and structurally characterized. The title compounds showed some antimycotic and plant growth regulating activities, especially in the case of 4d and 4c. The latter compound affected also the liver cancer 7402 cell viability.
A facile preparation of selenohydantoins using isoselenocyanate
Authors: Koketsu Mamoru , Takahashi Ayako , Ishihara Hideharu
Published: March 2009

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Reactions of isoselenocyanate with methyl aminoacetate hydrochlorides in the presence of triethylamine afforded selenohydantoins, 2‐selenoxoimidazolidin‐4‐ones, in high yields.
Phenacylsulfonylacetic esters — source for thiadiazoles, triazoles and oxadiazoles
Authors: Padmavathi Venkatapuram , Thriveni Pinnu , Reddy Boreddy Chandra Obula , Mahesh Konda
Published: March 2009

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A new class of thiadiazoles, triazoles and oxadiazoles were prepared from phenacylsulfonylacetic ester by protecting the carbonyl group by oximation. Deoximation was affected by using β‐cyclodextrin in the presence of an oxidizing agent.
Studies with enamines and azaenamines: A novel efficient route to 6‐amino‐1,4‐dihydropyridazines and their condensed derivatives
Authors: Ghozlan Said A. S. , Abdelhamid Ismail A. , Hassaneen Hamdi M. , Elnagdi Mohamed H.
Published: March 2009

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1‐Arylhydrazonopyruvaldehydes 1 react with α,β‐unsaturated nitriles 2 to yield 6‐amino‐1,4‐dihydropyridazines 4 that are converted into pyridazinones 5 via refluxing in an acetic acid/hydrochloric acid mixture and into the ethylidenemalononitrile derivatives 6 on reflux with malononitrile in ethanolic/piperidine solution.
Synthesis and fluorescence of 2h‐pyrone derivatives for organic light‐emitting diodes (OLED)
Authors: Mizuyama Naoko , Murakami Yuka , Kohra Shinya , Ueda Kazuo , Hiraoka Kyoko , Tominaga Yoshinori , Nagaoka Junko , Takahashi Kojiro , Shigemitsu Yasuhiro
Published: March 2009

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2H‐Pyrone derivatives were synthesized through the reaction of aryl acetyl compounds with ketene dithioacetals in the presence of sodium hydroxide, and they showed very strong fluorescence in the solid state. The light‐emitting region of these 2H‐pyrones is 447‐630 nm in the solid states.
Synthesis of an 4‐oxo‐1,4‐dihydropyridinomethylidene substituted 2‐indolinone
Authors: Lumetzberger Astrid , Löwe Werner , Weber Manuela , Luger Peter
Published: March 2009

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The (Z)‐3‐substituted 2‐indolinone 6 was prepared using the aldehydes 4 and 8 unknown up to now and 2‐indolinone.
Regioselective synthesis of some novel pyrazoles, isoxazoles, pyrazolo[3,4‐d]pyridazines and isoxazolo[3,4‐d]pyridazines pendant to benzimidazole
Authors: Shaaban Mohamed R. , Farag Ahmad M. , Saleh Tamer S. , Osman Fayez H.
Published: March 2009

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2‐Acetyl‐1‐methyl‐1H‐benzimidazole reacts with dimethylformamide‐dimethyl‐acetal (DMF‐DMA) to afford the corresponding E‐1‐(1‐methyl‐1H‐benzimidazol‐2‐yl)‐3‐N,N‐dimethylaminoprop‐2‐enone. The latter compound reacts regioselectively with some nitrilimines and nitrile oxides to afford the corresponding pyrazole and isoxazole derivatives, respectively. These reaction products react with hydrazine hydrate to give the novel pyrazolo[3,4‐d]pyridazine and isoxazolo[3,4‐d]pyridazine derivatives, respectively.
New derivatives of dibenzo[b,e][1,4]diazepin‐1‐ones by an efficient synthesis and spectroscopy
Authors: Cortés Eduardo Cortés , Cornejo Ana L. Valencia , de Cortés Olivia García‐Mellado
Published: March 2009

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An efficient synthesis of four steps to obtain twelve new derivatives of 3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐8‐[(o‐; and p‐methoxy)phenoxy]‐11‐[(o‐; and p‐R)phenyl]‐1H‐dibenzo[b,e][1,4]diazepin‐1‐ones IV, 1‐12 with possible biological and pharmacological activity as anticonvulsant and schizophrenia treatment in the central nervous system (CNS). The final products were obtained by condensation and cyclization between 3‐{4‐[(o‐; and p‐methoxy)phenoxy]‐1,2‐phenylenediamine}‐5,5‐dimethyl‐2‐cyclohexenone with (o‐; and p‐R)benzaldehyde. The structure of all products was corroborated by spectroscopy of ir, 1H‐nmr, 13C‐nmr, with bidimensional experiments and MS in Low and high resolution with Collision‐Induced Dissociation experiments (CID).
Synthesis and spectral determination of new derivatives of 1‐[(p‐substituted)phenyl]‐3a‐[(o‐ and p‐substituted)phenyl]‐5‐chloro‐9‐methylthio‐10,3a‐dihydro‐[1,2,4]‐oxadiazolo[2,3‐b][1,4]benzodiazepines
Authors: Cortés Eduardo , Ramírez Erik Peréz , de Cortés Olivia García‐Mellado
Published: March 2009

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A new synthesis to obtain eight novel derivatives of 1‐[(p‐substituted)phenyl]‐3a‐[(o‐ and p‐substituted)‐phenyl]‐5‐chloro‐9‐methylthio‐10,3a‐dihydro‐[1,2,4]‐oxadiazolo[2,3‐b][1,4]benzodiazepines with possible biological and pharmacological activity as anxiolytics, hypnotics, anticonvulsants in the central nervous system. The final products were obtained by condensation between 2‐methylthio‐5‐[(o‐; p‐substituted)‐phenyl]‐3H‐7‐chloro‐[1,4]benzodiazepine with benzonitrile oxide generated in situ from benzohydroxamoyl chloride in triethylamine. The structure of all products was corroborated by ir, 1H‐nmr, 13C‐nmr, with experiments bidimensional and ms in low and high resolution.
Synthesis of substituted 3‐pyrrolidinecarbonitriles
Authors: Maruoka Hiroshi , Okabe Fumi , Yamagata Kenji
Published: March 2009

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Cyclopropanes substituted at the same ring carbon by two electron‐withdrawing groups such as alkoxycarbonyl or cyano group react with the primary arylamines via a ring‐opening reaction and ensuing intramolecular cyclization to form substituted pyrrolidines.
An efficient and high yielding protocol for the synthesis of substituted dihydropyrimidin‐2(1h)‐ones and spiro‐fused heterocycles by involving tandem reactions
Authors: Bose D Subhas , Idrees MohD.
Published: March 2009

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A simple and efficient method has been developed for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones by a one‐pot three component cyclocondensation reaction of alkyl acetoacetates, aldehyde, and urea in the presence of a catalytic amount of the reusable catalyst zinc per chlorate hexahydrate, Zn(ClO4)2.6H2O (10 mol %) the scope of this protocol is utilized for the synthesis of mitotic Kinesin EG5 inhibitor monastrol and new class of fused heterobicyclic compounds in high yields.
Preparation of 4,5‐dihydro‐1,3‐selenazoles by reaction of aromatic primary selenoamides with acetylenedicarboxylate
Authors: Koketsu Mamoru , Ando Hiromune , Sasaki Tomomi , Ishihara Hideharu
Published: March 2009

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Reactions of primary selenoamides with dimethyl acetylenedicarboxylate afforded 2‐aryl‐5‐methoxy‐carbonylmethylene‐4,5‐dihydro‐1,3‐selenazol‐4‐ones in moderate to high yields. Reactions of the primary selenoamides with acetylenedicarboxylic acid gave 2‐aryl‐5‐carboxymethylene‐4‐ethoxy‐4,5‐dihydro‐1,3‐selenazol‐4‐ols in moderate yields.
Convenient synthesis of c2‐symmetric diazepinium salts derived from 1,1′‐binaphthyl‐2,2′‐diamine
Authors: Herrmann Wolfgang A. , Baskakov Denys , Ruhland Klaus
Published: March 2009

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New C2‐symmetric atropisomeric diazepinium salts were prepared utilizing Vilsmeier‐Haack activation of corresponding formamide precursors by phosgene solution in toluene. The structures of these substances were verified by X‐ray diffraction.
Synthesis and anti‐HIV activity of n‐(3‐amino‐3,4‐dihydro‐4‐oxopyrimidin‐2‐yl)‐4‐chloro‐2‐mercapto‐5‐methylbenzenesulfonamide derivatives
Authors: Brzozowski Zdzislaw , Sączewski Franciszek
Published: March 2009

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A series of N‐(3‐amino‐3,4‐dihydro‐4‐oxopyrimidin‐2‐yl)‐4‐chloro‐2‐mercapto‐5‐methylbenzenesulfonamide derivatives 10‐17 have been synthesized as potential anti‐HIV agents. The in vitro anti‐HIV‐1 activity of these compounds has been tested at the national Cancer Institute (Bethesda, MD), and the structure‐activity relationships are discussed. The selected N‐[3‐amino‐3,4‐dihydro‐6‐(tert‐butyl)‐4‐oxothieno[2,3‐e]pyrimidin‐2‐yl]‐4‐chloro‐2‐metcapto‐5‐methylbenzenesulfonamide (14) showed good anti‐HIV‐1 activity with 50% effective concentration (EC50) value of 15 μM and weak cytotoxic effect (IC50 = 106 μM).
Convenient way to 5‐substituted 4‐amino‐2,3‐dihydro‐4H‐1,2,4‐triazole‐3‐thiones
Authors: Smičius Romualdas , Burbuliene Milda Malvina , Jakubkienė Virginija , Udrwėnaitė Emilija , Vainilavičius Povilas
Published: March 2009

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Various 4‐amino‐2,3‐dihydro‐4H‐triazoles with aromatic, aliphatic and heterocyclic substituents at the C(5) position were synthesized from corresponding esters and thiocarbohydrazide. This method allows the synthesis these heterocycles in a short time and at reduced expenses.
Fluorescent behavior of 2‐(3,4,5,6‐tetrafluoro‐2‐hydroxyphenyl)imidazo‐[1,2‐a]pyridine in the presence of metal perchlorate
Authors: Tanaka Kiyoshi , Kurushima Tohru , Iwata Satoru , Shimada Syunsuke
Published: March 2009

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2‐(3,4,5,6‐Tetrafluoro‐2‐hydroxyphenyl)imidazo[1,2‐a]pyridine (1) emits long wavelength light around 540 nm both in polar and in nonpolar solvents. Zn2+ perchlorate in acetonitrile causes the intermediate wavelength emission around 430 nm, which is ascribed to the species where the imidazole nitrogen atom and the phenolate oxygen atom bridge Zn2+. In the presence of Hg2+ and Al3+ perchlorates, short wavelength emission around 370 nm is strongly increased and this fluorescent enhancement is attributable not to the coordination of Hg2+ and Al3+ to 1 but to the formation of the salt of perchloric acid of 1.
Novel compounds for the synthesis of cefdinir
Authors: Rao K. V. V. Prasada , Dandala Ramesh , Sivakumaran Meenakshisunderam , Rani Ananta , Naidu A.
Published: March 2009

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Preparation of two new compounds 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazolyl‐(Z)‐2‐(2‐amino‐4‐thiazolyl)‐2‐trityloxyiminoacetate (14) and 2‐mercapto‐5‐methyl‐1, 3,4‐thiadiazolyl‐ (Z)‐2‐(2‐amino‐4‐thiazolyl)‐2‐acetyloxyiminoacetate (12) and their use in the preparation of 7β‐[(Z)‐2‐(2‐amino‐4‐thiazolyl)‐2‐hydroxyiminoacetamido]‐3‐vinylcephem‐4‐carboxylic acid, also known by the generic name Cefdinir (1) has been accomplished in a single step by coupling with 7‐amino‐3‐vinylcephem‐4‐carboxylic acid (7) with purity of greater than 99% by HPLC.
Evidences of some unusual behaviours of 2‐aminothiazol and 2‐aminobenzothiazol in reactions with formaldehyde and glyoxal
Authors: Ghandi Mehdi , Olyaei Abolfazl
Published: March 2009

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In contrast to the previously reported acid‐catalyzed reaction of 2‐aminothiazole with aqueous formaldehyde in water at 0‐5 °C which afforded N,N′‐bis(2‐thiazolyl)methanediamine (4), 5,5′‐methylenebis(2‐aminothiazole) (5) is obtained as the unique product under reflux conditions. Reaction of 2‐aminobenzothiazole with aqueous formaldehyde in acetonitrile at 0‐5 °C or under reflux conditions produces (2‐benzothiazolylamino)methanol (6) or N,N′‐bis(2‐benzothiazolyl)methanediamine (7), respectively. Heating monoamine 6 in acetonitrile remarkably yields the symmetric diamine 7. While cyclocondensation of 2‐aminothiazole with aqueous glyoxal in acetonitrile gives 3,4,8,9‐tetrahydroxy‐7,10‐bis(2‐thiazolyl)‐2,5‐dioxa‐7,10‐diazabicyclo[4.4.0]decane (8), reaction of 2‐aminobenzothiazole with glyoxal fails to produce similar results; In the presence of aqueous formaldehyde, although the former reaction leads to the formation of 4‐hydroxy‐5‐(thiazolylamino)‐1,3‐bis(2‐thiazolyl)imidazolidine (9), utilization of 2‐aminobenzothiazole gives 4,5‐dihydroxy‐1,3‐bis(2‐benzothiazolyl)imidazolidine (10). Condensation of either 6 or 7 with aqueous glyoxal affords compound 10. Details of the reactions will be discussed in this presentation.
Synthesis of pyrazolo‐annelated heterocyclic ring compounds such as pyrazolo[3,4‐b]pyridines and pyrazolo[4′,3′:5,6]‐pyrido[2,3‐d]pyrimidines
Authors: Jachak Madhukar N. , Avhale Appasaheb B. , Toche Ragunath B. , Sabnis Ram W.
Published: March 2009

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A series of pyrazolo[3,4‐b]pyridines has been synthesized by Friedländer condensation of 5‐amino‐pyrazole‐4‐carbaldehyde 1 with active methylene compounds in basic medium. Pyrazolo[4′3′:5,6]pyrido‐[2,3‐d]pyrimidines have been synthesized from pyrazolo[3,4‐b]pyridines using substituted urea and acetic anhydride.
Synthesis of 2,2′‐bipyridyl‐type compounds via the suzuki‐miyaura cross‐coupling reaction
Authors: Jones Nicholas A. , Antoon James W. , Bowie Alfred L. , Borak J. Brian , Stevens Erland P.
Published: March 2009

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2,2′‐Bipyridyl‐type compounds may be prepared by Suzuki‐Miyaura coupling of a 2‐pyridylboronic ester with 2‐haloazines and ‐azoles. Ten examples are presented with yields of 47 to 84%. Both arylbromides and arylchlorides undergo the coupling, but the reaction is sensitive to ring substitution adjacent to the halogen.
Synthesis and antimicrobial activity of some new N‐(substituted phenyl)‐N′‐[2,3‐dihydro‐2‐oxido‐3‐(4′‐fluorophenyl)‐1H‐(1,3,2)benzoxazaphosphorin 2‐yl]ureas
Authors: Haranath P. , Kumar V. Sreedhar , Reddy C. Suresh , Raju C. Naga , Reddy C. Devendranath
Published: March 2009

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Substituted benzoxazaphosphorin 2‐yl ureas were synthesized by reacting 2‐(4‐fluoro‐phenylamino)‐methylphenol (4) with different carbamidophosphoric acid dichlorides (3) in the presence of triethylamine in dry toluene at 45‐50 °C and characterized by spectral data. These compounds were found to possess good antimicrobial activity.
Nitropyridyl isocyanates in 1,3‐dipolar cycloaddition reactions
Authors: Holt Jarle , Fiksdahl Anne
Published: March 2009

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The reactivity of 3‐nitro‐4‐pyridyl isocyanate (7) and 5‐nitropyridin‐2‐yl isocyanate (9) in 1,3‐dipolar cycloaddition reactions with azides and pyridine N‐oxides has been investigated. 1,3‐Dipolar cycloaddition to trimethylsilylazide (TMSA) afforded the respective tetrazolinones, 1‐(3‐nitropyridin‐4‐yl)‐1H‐tetrazol‐5(4H)one (8, 50 %) and 1‐(5‐nitropyridin‐2‐yl)‐1H‐tetrazol‐5(4H)one (11, 64 %). Respectively, 1,3‐dipolar cycloaddition of nitropyridyl isocyanates 7 and 9 to 3,5‐dimethylpyridine N‐oxide (14), 3‐methylpyridine N‐oxide (21) and pyridine N‐oxide (22) gave the substituted amines, 3,5‐dimethyl‐N‐(3‐nitropyridin‐4‐yl)pyridin‐2‐amine (17), 3,5‐dimethyl‐N‐(5‐nitropyridin‐2‐yl)pyridin‐2‐amine (20), N‐(5‐nitropyridin‐2‐yl)pyridin‐2‐amine (24), 5‐methyl‐N‐(5‐nitropyridin‐2‐yl)pyridin‐2‐amine (23) and 3‐methyl‐N‐(5‐nitropyridin‐2‐yl)pyridin‐2‐amine (25) in 65 ‐ 80 % yield, obtained by cycloaddition, rearrangement and decarboxylation. The results demonstrate that the nitropyridyl isocyanates (7,9) readily undergo 1,3‐dipolar cyloaddition reactions similar to phenyl isocyanates.
Synthesis of thiazolines by the reaction of aryl ketonitriles with cysteamine via microwave irradiation
Authors: Kamila Sukanta , Biehl Edward R.
Published: March 2009

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Thiazolines were synthesized in a one‐pot reaction in excellent yield using a newly developed methodology. Ketonitriles were directly condensed with cysteamine (2‐amino‐thioalcohol) via microwave irradiation at 210°C for 10 minutes under solvent free conditions and without any solid support. All the compounds were characterized by 1H nmr, 13C nmr spectroscopy and elemental analyses.
A novel synthesis of indole derivatives by the reaction of N‐arylhydroxamic acids with malononitrile
Authors: Tomioka Yukihiko , Ohkubo Kimiko , Maruoka Hiroshi
Published: March 2009

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An approach to indole derivatives from N‐arylhydroxamic acids and malononitrile via a [3,3]‐sigmatropic rearrangement and intramolecular cyclization is described. Reactions of N‐arylhydroxamic acids 1a‐c, 2a‐c and 3a‐c with malononitrile in the presence of triethylamine at room temperature gave the corresponding α‐cyanoacetamide derivatives 4a‐c, 5a‐c, 6a‐c, 7a‐c and 8a‐c. Thermal treatment of 4a‐c, 5a‐c and 7a‐c with a base, e.g. triethylamine and sodium methoxide, caused intramolecular cyclization and deacylation to afford the corresponding indole derivatives 9‐11.
Reaction of 3‐formylchromone‐N‐benzoylhydrazone with ketenes. Synthesis and structural studies of chromone 1,3,4‐oxadiazolines
Authors: Kaspentakis George C. , Tsoleridis Constantinos A. , Stephanidou‐Stephanatou Julia
Published: March 2009

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The reaction of 3‐formylchromone‐N‐benzoylhydrazone with ketenes, prepared in situ from the corresponding acid chlorides 2a‐d and the mixed anhydride 2e was studied. In all cases 2‐(4′‐oxo‐4′H‐3′‐chromyl)‐5‐phenyl‐2,3‐dihydro‐1,3,4‐oxadiazoles (3) were isolated in yields varying from 40 to 80%. A full structure assignment of all products has been made on the basis of 1D and 2‐D (COSY H‐H, COSY C‐H, COLOC C‐H) NMR spectra. A plausible reaction mechanism is also proposed based on theoretical approaches and experimental results.
Cycloaddition reactions with 2,3‐benzodiazepine derivatives
Authors: Kertész Máriusz , Pallagi István , Sólyom Sándor
Published: March 2009

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We report here on some 3+2 dipolar cycloaddition reactions of propargyl, allyl and cyano substituted 2,3‐benzodiazepines within situgenerated nitrile oxides and diazomethane. The reactivity of carbon‐nitrogen double bonds of the 5H‐[2,3]benzodiazepine ring system was also noticed.
Biginelli‐like three component reaction: Synthesis of some new ethyl 6‐ethoxycarbonylmethyl‐4‐aryl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate derivatives
Authors: Azizian Javad , Mohammadi Ali A. , Kohshari M. , Karimi Ali R. , Mohammadizadeh Mohammad R.
Published: March 2009

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In the context of our high‐throughput organic synthesis program, we have studied the reactivity of special β‐keto esters toward the Biginelli reaction. We have found that a diethyl‐3‐oxoglutarate reacts with one molecule of urea and one molecule of aldehyde under solvent‐free conditions to give a new family of 3,4‐dihydropyrimidin‐2(1H)‐ones in good yields.
Synthesis of a new class of sulfone linked bisheterocycles
Authors: Padmavathi Venkatapuram , Reddy Boreddy Chandra Obula , Mohan Annaji Venkata Nagendra , Padmaja Adivireddy
Published: March 2009

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Some bisheterocycles having pyrrole and oxazoline/thiazoline units were synthesized from Z‐styrylsulfonylacetic acid methyl esters using samarium chloride.
1,3‐Dibromo‐5,5‐dimethylhydantoin (DBH) as an efficient promoter for acetylation of 3‐arylsydnones in the presence of acetic anhydride under neutral conditions
Authors: Azarifar Davood , Bosra Hassan Ghasemnejad , Tajbaksh Mahmood
Published: March 2009

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1,3‐Dibromo‐5,5‐dimethylhydantoin (DBH) has been found to efficiently promote the conversion of various 3‐arylsydnones to their 4‐acetyl congeners in the presence of acetic anhydride under neutral conditions in satisfactory yields.
Synthesis of 5,6,7,8‐tetrahydroindolizines via a domino‐type transformation based on the rhodium catalyzed hydroformylation of N‐(β‐methallyl)pyrroles
Authors: Rocchiccioli Silvia , Guazzelli Giuditta , Lazzaroni Raffaello , Settambolo Roberta
Published: March 2009

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Variously substituted 5,6,7,8‐tetrahydroindolizines can be easily synthesized via a domino reactions sequence under rhodium catalyzed hydroformylation of N‐(β‐methallyl)pyrroles. The later are readily prepared from properly functionalized pyrroles via phase‐transfer N‐allylation in the presence of 18‐crown‐6 and potassium tert‐butoxide.
Deoxygenation of pyridine N‐oxides with dimethylthiocarbamoyl chloride
Authors: Ponaras Anthony A. , Zaim Ömer
Published: March 2009

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Treatment of pyridine N‐oxides with dimethylthiocarbamoyl chloride in boiling acetonitrile effects chemoselective deoxygenation to pyridines.
A new synthesis of alkaloid (S)‐3‐hydroxypiperidin‐2‐one and its O‐TBS protected derivative
Authors: Huang Pei‐Qiang , Chen Guo , Zheng Xiao
Published: March 2009

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From the known lactone (S)‐4, easily derived from L‐glutamic acid, a scalable approach to chiral building block O‐silylated 3‐hydroxypiperidin‐2‐one 3 and alkaloid 1 was achieved in five and six‐steps respectively. The key steps are a chemoselective amidation of lactone‐ester 5 and a one‐pot reductive borane‐decomplexation, N‐debenzylation and cyclization.
Alkylation of azoles: Synthesis of new heterocyclic‐based AT1‐non‐peptide angiotensin (II) receptor antagonists
Authors: Al‐Azmi Amal , George Paulson , El‐Dusouqui Osman M. E.
Published: March 2009

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Several novel analogues of Losartan2were synthesized as potential non‐peptide angiotensin (II) receptor antagonists. In these non‐peptide analogues, the tetrazole and the substituted imidazole rings of Losartan2were replaced, respectively, by a carboxylic acid function or its methyl ester and substituted triazole, imidazole or benzimidazole moieties. The biphenyl bromide precursor3(BPE) used to introduce the linker between the acid/ester function and the heterocyclic moiety was synthesized using Suzuki biphenyl coupling and then incorporated into the target molecule by simple nucleophilic substitution. The fixed N‐aryl isomeric forms of several azole and benzimidazole tautomers were successfully separated by HPLC using 50% aqueous acetonitrile as eluent. Intermediate reaction products and final target compounds were fully characterized spectroscopically.
Synthesis of some novel fused oxo‐ and thiopyrimidines via an intramolecular friedel‐crafts reaction
Authors: Mobinikhaledi Akbar , Foroughifar Naser , Javidan Abdollah , Amini Ehsan
Published: March 2009

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1H‐Indeno[1,2‐d]pyrimidine‐2,5(3H,9bH)‐dione derivatives 2(a‐i) and 2,3‐dihydro‐2‐thioxo‐1H‐indeno[1,2‐d]pyrimidine‐5(9bH)‐ones 2(j‐q) were synthesized via an intramolecular Friedel‐Crafts reaction between the aryl and ester group of ethyl 6‐methyl‐4‐aryl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylates 1a‐i, and their thioxo analogs using AlCl3 and acetyl chloride in nitrobenzene. Yields of the products, after washing with THF, were of the order of 45‐69%. IR and NMR spectroscopy together with elemental analysis were used for identification of these compounds.
Asymmetric alkylation of N‐acylisoindolin‐1‐ones via α‐bromoimides: A novel route to 1‐substituted isoindolines
Authors: Müller Andreas , Polborn Kurt , Wanner Klaus T.
Published: March 2009

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Key intermediate in the synthesis of the title compounds 9a‐c and 10a‐c was the chiral α‐bromoimide 1 which has been prepared by radical bromination of the corresponding N‐acylisoindolin‐1‐one 13. 1 was alkylated with silyl enol ethers under Lewis acid catalysis using α‐amidoalkylation methodology. N,N‐diacyliminium ion 14 is presumably the intermediate in this reaction. Further transformations of the alkylated compounds yielded 1‐substituted isoindolines as target compounds.
Metallation reactions. XXXVI. A study on the metallation of (methylthio)‐ and (methylsulfonyl)thiophenes
Authors: Fattuoni Claudia , Usai Michele , Cabiddu Maria G. , Cadoni Enzo , De Montis Stefania , Sotgiu Francesca , Cabiddu Salvatore
Published: March 2009

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Methylthio‐ and methylsulfonyl thiophenes were polymetallated by n‐buthyllithium and superbase (LICKOR) in one‐step. 2‐(Methylthio)thiophene was bimetallated in 5 and in alpha to the methylthio sulfur atom by superbase. 3‐(Methylthio)thiophene was bimetallated in both 2 and 5 positions by the organolithium and trimetallated in these two positions and in alpha to the thioethereal sulfur atom by superbase. 3‐(Methylsulfonyl)thiophene was bimetallated in 2 and in alpha to the sulfonyl sulfur atom by the organolithium while the 2‐(methylsulfonyl)thiophene underwent degradation in the same conditions.
Reaction of phthalaldehydic acid with different substituted aniline as well as hydrazine derivatives
Authors: Khattab Sherine N. , Hassan Seham Y. , El‐Faham Ayman , El Massry Abdel Moneim M. , Amer Adel
Published: March 2009

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Phthalaldehydic acid 1 is often represented as having two tautomeric forms 1a and 1b. The reaction of phthalaldehydic acid with different aryl amine and heterocyclic aryl hydrazine derivatives afforded different products depending on the reaction conditions such as solvent and temperature.
Synthesis of substituted 1,2,4‐oxadiazoles from substituted acid chlorides and amidoximes under mild conditions
Authors: Bora Rajesh O. , Farooqui Mazahar
Published: March 2009

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Substituted amidoximes have been synthesized, isolated and converted into substituted oxadiazoles as a novel heterocyclic compounds under mild conditions in good to excellent yield.
Synthesis of mixed‐donor azaoxathia macrocyclic tetraamides, acyclic polyether di/and tetraamides and their C‐pivot lariat derivatives
Authors: Abbas Ashraf A.
Published: March 2009

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The macrocyclic tetraamides11a‐eand 15‐hydroxy macrocyclic tetraamides23a‐cwere prepared in good yields by the nucleophilic reaction of the potassium salts of the bis‐phenoles10a‐cwith the appropriate dihalo compounds5a‐dand15.Moreover, the acyclic diamides7, 9, 17‐21and bis‐acyclic tetraamide22were obtained in high yields by the reaction of the appropriate dichloro compounds with different phenoxides and secondary amines. Acylation of23a‐cwith different acid chlorides gave the corresponding esters24a‐c.Compounds24a‐creacted with different secondary amines to afford the corresponding novel lariat macrocycles25a‐din high yields.
Hetarenium salts from pentafluoropyridine. Syntheses, spectroscopic properties, and applications
Authors: Schmidt Andreas , Mordhorst Thorsten , Namyslo Jan Christoph , Telle Werner
Published: March 2009

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Reaction of pentafluoropyridine with nucleophilic heteroaromatics such as 4‐(dimethylamino)pyridine, 4‐(pyrrolidin‐1‐yl)pyridine, 4‐(morpholin‐4‐yl)pyridine, 4‐aminopyridine, and 3,4‐diaminopyridine resulted in the formation of 4‐hetarenium substituted tetrafluoropyridines. The 4‐(dimethylamino)‐pyridinium derivative underwent substitution reactions with isopropanolate, isopropanethiolate, and benzylthiolate to F2,F3,O4,F5,F6‐ and O2,F3,O4,F5,F6‐pentasubstituted pyridines as well as their sulfur analogs. N‐Propylamine, isopropylamine, and piperidine formed 4‐amino‐N2,F3,F5,F6‐pentasubstituted pyridines in the presence of sodium amide as base, whereas morpholine gave the 4‐amino‐2,6‐bis‐morpholino‐substituted 3,5‐difluoropyridine. 19F, 15N, 13C, and 1H nmr spectrocopy was performed to elucidate the structures of the substitution products.
Synthesis of some 2‐oxo and 2‐thioxo substituted pyrimidines using solvent‐free conditions
Authors: Mobinikhaledi Akbar , Forughifar Naser , Alipour Safari Jil A. , Amini EhsaN.
Published: March 2009

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A series of oxo‐ and thioxopyrimidines 4(a‐m) were synthesized by one‐pot three components cyclocondensation reaction of β‐ketoester, aldehyde and urea/thiourea using benzyltriethylammonium chloride as a catalyst under solvent‐free conditions. The yields of products following recrystallization from ethanol were of the order of 65‐87%. IR and 1HNMR spectroscopy and elemental analysis were used for identification of these compounds.
Synthesis and reactivity of 1‐amino‐4‐methyl‐3,4‐dihydro‐5H‐pyrazolo[3′,4′:4,5]pyrimido[1,6‐a]benzoimidazolo‐5‐one
Authors: Abdelhamid Abdou O. , Awad Ahmed A.
Published: March 2009

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Pyrimido[2“,1”:5′,6′]pyrazolo[3′,4′:4,5]‐pyrimido[1,6‐a]benzoimidazoloe‐2,8(1H,7H)‐diones, and [1,2,4]‐triazino‐[3“,4”:5′,6′]pyrazolo[3′,4′:4,5]pyrimido[1,6‐a]benzimidazol‐8(7H)‐ones were synthesized in a good yields via 1‐amino‐4‐methyl‐3,4‐dihydro‐5H‐pyrazolo[3′,4′:4,5]pyrimido[1,6‐a]benzoimidazolo‐5‐one and the appropriate active methylene compounds. Structures of the newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative synthesis methods whenever possible.
Studies with 2‐arylhydrazononitriles: A novel simple, efficient route to 5‐acyl‐2‐substituted‐1,2,3‐triazol‐4‐amines
Authors: Aziz Suzan Ibrahim , Anwar Hany Fakhry , Elnagdi Mohamed Hilmy , Fleita Daisy Hanna
Published: March 2009

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Efficient route to 5‐acyl‐2‐substituted‐1,2,3‐triazol‐4‐amines via reaction of 3‐oxo‐2‐(arylhydrazono)‐pentanenitrile with hydroxylamine hydrochloride is reported. X‐ray crystal structure has been made to confirm the structure of reaction products.
Synthesis and antimicrobial activity of some novel furyl and benzimidazole substituted benzyl ethers
Authors: Güven Özden Özel , Erdoǧan Taner , Göker Hakan , Y1ld1z Sulhiye
Published: March 2009

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In this study, a series of novel furyl and benzimidazole substituted benzyl ethers were synthesized and evaluated for antibacterial and antifungal activities against S. aureus, Methicillin resistant S. aureus (MRSA), E. coli, C. albicans and C. krusei. Compound 6f and 6h exhibited the most potent anti‐bacterial activity with lowest MIC values of 3.12 μg/mL against S aureus and MRSA, respectively.
Synthesis of alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates for evaluation as calcium channel antagonists
Authors: Kaur Kuljeet , Knaus Edward E.
Published: March 2009

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The Bigenelli acid catalyzed condensation of 2‐pyridylcarboxaldehyde (1), urea (2) and an alkyl acetoacetate (3) afforded the respective alkyl (Me, Et, i‐Pr, i‐Bu, t‐Bu) 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates (4a‐e). The most potent calcium channel antagonist ethyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylate (4b, IC50 = 1.67 × 10−5 M) wasa much weaker calcium channel antagonist than the reference drug nifedipine (Adalat®, IC50 = 1.40 × 10−8 M) on guinea pig ileal longitudinal smooth muscle (GPILSM). The alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates did not show any inotropic effect on heart since no increase, or decrease, in the contractile force of guinea pig left atrium was observed. These structure activity studies show that the alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates (4a‐e) are partial bioisosteres of nifedipine with respect to calcium channel antagonist activity on guinea pig ileal longitudinal smooth muscle (GPILSM).
Synthesis and herbicidal activities of a series of di(aminopyrazoly) ketone derivatives
Authors: Li Jun‐Fei , Zhu You‐Quan , Wang Xin , Yang Hua‐Zheng
Published: March 2009

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In order to obtain new lead compounds with high herbicidal activity, a series of 5‐amino pyrazole derivatives were designed and synthesized using a series of relational synthons. Their structures were determined by IR, 1H NMR, and elemental analyses. These compounds were screened for herbicidal activities against rape and barnyard grass. Their structure‐activity relationships are discussed.
A post‐SCF quantum chemistry study on local minima of 8‐oxo‐guanine stacked with all four nucleic acid bases in B‐DNA conformations
Authors: Cysewski Piotr , Czyżnikowska‐Balcerak Żaneta
Published: March 2009

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The post SCF MP2/6‐31G*(d=0.25) method was applied to obtain potential energy surface of 8‐oxoguanine stacked with all four canonical DNA bases. The spatial neighbourhood was scanned of stacked complexes found in the native B‐DNA. The presented results suggest that the hydroxyl radical modification of guanine at C8 position has significant impact on structural, energetic, orbital and electrostatic properties of stacked complexes with canonical DNA bases. The pair stabilization energy, including electron correlation terms, suggests that the 5′‐A/GA‐3′ pair is the most stable among all of the studied complexes. The 8‐oxo‐guanine has been found as a source of significant changes in electroaccepting properties compared to stacked pairs formed by canonical guanine since both electron affinities and localization of HOMO orbital were altered. However, electro‐donation abilities are not modified after replacement of guanine with 8‐oxo‐guanine irrespectively on the context of B‐DNA bases.