bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selenium dioxide oxidation of alkylcoumarins and related methyl‐substituted heteroaromatics
Authors: Ito Kiichi , Nakajima Kaoru 
Published: April 2009

AbstractBy the use of selenium dioxide as the specific oxidizing agent in the coumarin series, the 4‐ethyl, 4‐propyl and 4‐benzyl substituents of coumarin were converted into α‐alcohols 2 and/or ketones 3, while 3‐methyl‐ and 3‐benzylcoumarins were converted into 3‐acyl derivatives 7. The methyl substituent of the analogous thiocoumarin 5, chromones 10 or thiochromone 11 was also oxidized into the formyl functionality. Facile oxidative desulfurization into the ketone functionality, prior to methyl oxidation, was observed for the thione derivatives of 1a, 5, 6 and 10.
Synthesis of 5‐phenylpyrrolo[1,2‐b][1,2,5]‐triazepin‐2(3H)‐ones
Authors: Hamer R. Richard L. , Effland Richard C. , Klein Joseph T. , Huger Francis P. , Wilker Jeffrey C. 
Published: April 2009

AbstractThe synthesis of a series of 5‐phenylpyrrolo[1,2‐b][1,2,5]triazepin‐2(3H)‐ones 1 as potential anxiolytic agents is described. Benzoylation of 1‐phthalimidopyrrole, followed by hydrolysis, gave the 1‐amino‐2‐benzoylpyrroles 3. These were further functionalized to give the penultimate 1‐aminoacetamido‐2‐benzoylpyrroles 8 and 9, which were cyclized to the target pyrrolotriazepines 1.
Synthesis of some methylfurochromones as potential photochemotherapeutic agents
Authors: Rodighiero P. , Pastorini G. , Chilin A. , Manzini P. , Guiotto A. 
Published: April 2009

AbstractA number of new methylfurochromones with a linear psoralen like structure or an angular angelicin like structure were synthetized. The synthesis were performed starting from 7‐hydroxychromones variously methylated on which the furan ring was built. Methyl groups have been introduced into positions which look most promising for enhancement of the photoreactivity of the compound towards DNA.
Synthesis of 7,8,9,10‐tetrahydropyrido[3′,4′:4,5]pyrrolo[2,3‐c]quinolines
Authors: Schönafinger Karl , Yasenchak Christine M. , Vollman Anne , Ong Helen H. 
Published: April 2009

AbstractA series of structurally novel 7,8,9,10‐tetrahydropyrido[3′,4′:4,5]pyrrolo[2,3‐c,]quinolines, 4a‐c, were synthesized via a facile Fischer indole cyclization from the appropriately substituted hydrazinoquinolines 2a‐c. Acetamides 4a,c were hydrolyzed to 5a,b and further converted to tertiary amines 6a‐c. Potent antihypertensive activity has been observed with a number of the title compounds as well as the intermediate 3a.
Synthesis of 1,3,7,9,11,12,14‐heptazapentacene‐2,4,8,10‐(14H,3H,9H,12H)‐tetraones (mixed flavins) with oxidizing ability
Authors: Yoneda Fumio , Koga Masakazu 
Published: April 2009

Abstract1,3,7,9,11,12,14‐Heptazapentacene‐2,4,8,10(14H,3H,9 H,12H)‐tetraones (mixed flavins) were synthesized by the cyclization of 1,5‐dihydro‐8‐[N‐alkyl‐N‐(5‐nitrouracil‐6‐yl)]‐amino‐5‐ deazaflavins with the Vilsmeier reagent. The mixed flavins oxidized alcohol under neutral conditions in sunlight.
Synthesis of 1‐Aryl‐1H‐pyrazolecarbonitriles and related derivatives
Authors: Beck James R. , Lynch Michael P. , Wright Fred L. 
Published: April 2009

AbstractThe synthesis of 1‐aryl‐5‐cyano‐1H‐pyrazole‐4‐carboxylic acid, ethyl esters 1 is described. Subsequent chemistry led to relatively simple and unique pyrazole derivatives. Most important of these are 1‐aryl‐5‐(aminocarbonyl)‐1H‐pyrazole‐4‐carboxylic acids 2, which are chemical hybridizing agents in wheat and barley. The regioselective hydrolysis of 1‐(3‐chlorophenyl)‐1H‐pyrazole‐4,5‐dicarboxylic acid, dimethyl ester (7b) and subsequent chemistry is also described.
Tetrakis(alkylthio)thieno[3,4‐c]thiophene: Synthesis, stability, and reactivity
Authors: Yoneda Shigeo , Tsubouchi Kenji Ozaki, Akira , Kojima Hideo , Yanagi Kazunori 
Published: April 2009

AbstractThe synthesis of tetrakis(alkylthio)thieno[3,4‐c]thiophenes la‐e by the dimerization reaction of bis(alkylthio)cyclopropenethiones is described. The remarkable thermodynamic and kinetic stability suggests the significant electron‐accepting conjugation of the alkylthio substituents to the carbanionic 1, 3, 4, and 6 carbons in the framework. The isopropylthio‐ and ethylthio‐substituted thienothiophenes 1d and 1e undergo cycloaddition reactions with dienophiles such as N‐phenylmaleimide and dimethyl acetylenedicarboxylate to give the cycloadducts in moderate yields.
Spectroscopic identification of some derivatives of 3,4‐diamino‐4H‐1,2,4‐triazole and 3‐Hydrazino‐4H‐1,2,4‐triazole
Authors: Emilsson Håkan , Selander Hans 
Published: April 2009

AbstractSpectroscopic methods (ir, 1H‐ and 13C‐nmr, ms and uv) have been used for the structural elucidation and identification of different isomeric 1,2,4‐triazole derivatives, obtained by cyclisation reactions from appropriate diaminoguanidines. The four compounds 3,4‐diamino‐4H‐1,2,4‐triazole, 3‐hydrazino‐4H‐1,2,4‐triazole, 3‐amino‐4‐(2,6‐dichlorobenzylideneamino)‐4H‐1,2,4‐triazole and 3‐(2,6‐dichlorobenzylidenehydrazino)‐4H‐1,2,4‐triazole, were chosen as representative structures to illustrate the general spectroscopic properties for 3,4‐diamino‐ and 3‐hydrazino‐substituted 4H‐1,2,4‐triazoles and the corresponding hydrazones, with different substituents in the 5‐position of the triazole ring (alkyl‐, aralkyl‐, mercapto‐, hydroxy‐ and amino‐groups). Nmr and uv spectroscopy were found to be the best methods for confirmation of the different series of hydrazones, while ir and nmr were found to be suitable for the structural elucidation of compounds in the series of 3,4‐diamino‐ and 3‐hydrazino‐4H‐1,2,4‐triazoles, respectively.
12H‐dibenzo[d,g][1,3,2]dioxaphosphocins: Synthesis, structures and “through‐space” spin‐spin coupling in their NMR spectra
Authors: Goddard John D. , Payne Alan W. , Cook Nick , Luss Henry R. 
Published: April 2009

AbstractA series of 12H‐dibenzo[d,g][1,3,2]dioxaphosphocins has been prepared by the reactions of bisphenols with either ethyl phosphorodichloridate or phosphorus pentasulfide. The structures of a pair of cis and trans isomers in this series were elucidated by X‐ray crystallography. Both isomers adopt the boat‐chair conformation in the solid state with the bulky group at C‐12 in the pseudo‐equatorial position. Some flattening of the heterocyclic ring due to the pseudo‐axial ethoxy group was observed in the cis isomer. A novel transannular cyclisation reaction was observed in the mass spectra of the cis isomers and this has allowed us to assign the configurations of all the isomers in the series. The pmr spectra of the compounds have been explained in terms of the rigid boat‐chair conformation; however, as bulky groups were introduced at C‐12, signs of mobility were observed for the cis isomers and an equilibrium was established with mobile boat forms. A stereospecific long‐range coupling between P and the proton at C‐12 could be transmitted “through space” by the antiperiplanar lone‐pair electrons on the ring oxygen atoms.
Cyclization of a cysteine conjugate ofN‐(3,5‐Dichlorophenyl)succinimide
Authors: Shih Hsien‐Cheng , Rankin Gary O. 
Published: April 2009

AbstractN‐(3,5‐Dichlorophenyl)‐2‐cysteinylsuccinimide methyl ester hydrochloride (5) was prepared fromN‐(3,5‐dichlorophenyl)maleimide (3) and cysteinyl methyl ester hydrochloride. Attempted neutralization of the cysteine conjugate salt with triethylamine resulted in spontaneous cyclization of5to form the more stable 2‐(N‐3,5‐dichlorophenylcarbamoylmethyl)‐5‐carbomethoxy‐1,4‐thiazine‐ 3‐one (6). Similar results might be expectedin vivoshould these metabolites of succinimides be formed.
Synthese et isomerisation de methoxycarbonyl‐5 dihydropyrannones‐2
Authors: Rocher Jean‐Philippe , Ahmar Mohammed , Paris Joelle 
Published: April 2009

AbstractLa synthèse de méthoxycarbonyl‐5 méthyl‐4 dihydro pyrannones‐2 est réalisée par condensation du méthyl‐3 glutaconate de diméthyle sur des cétones. Les conditions opératoires permettant d'isoler sélectivement des pyrannones isomères sont discutées. La structure des différents produits réactionnels est établie par spectrométrie rmn 1H et 13C.
N‐ and C‐sulfenylation of 1‐(1,2‐oxazol‐3 (and 5)‐yl)‐3‐alkylureas with organic sulfenyl chlorides
Authors: Pilgram Kurt H. , Gale Laird H. 
Published: April 2009

AbstractCondensation of chlorocarbonylsulfenyl chloride 1 with 1‐(5‐(1,1‐dimethylethyl)‐1,2‐oxazol‐3‐yl)‐3‐methylurea 4a has been found to give isomeric 2,4‐disubstituted‐1,2,4‐thiazolidine‐3,5‐diones 5 and 6. Assignments are confirmed by the X‐ray structure data of 6. Sulfenylation with alkoxycarbonylsulfenyl chlorides 7 and trichloromethylsulfenyl chloride 10 of 4 occurs exclusively on N‐1 rather than N‐3 of the urea moiety. With the isomeric 1‐[3‐(1,1‐dimethylethyl)‐1,2‐oxazol‐5‐yl]‐3‐methylurea 14 and ethoxycarbonylsulfenyl chloride 7b, C‐sulfenylated derivatives 15 and 16 are formed in low yield.
Synthesis of 5H‐Triazolo[1,5‐d]‐ and 5H‐ Tetrazolo‐ [1,5‐d]thieno[3,2‐f]‐1,4‐diazepin‐6(7H)‐ones
Authors: Shishoo C. J. , Devani M. B. , Ullas G. V. , Ananthan S. , Bhadti V. S. 
Published: April 2009

Abstract5H‐Triazolo[1,5‐d]‐ and 5H‐tetrazolo[1,5‐d]thieno[3,2‐f]‐1,4‐diazepin‐6(7H)‐ones have been obtained by the base catalysed ring expansion reaction of 5‐chloromethyl‐1,2,4‐triazolo[1,5‐c]‐ and 5‐chloromethyltetrazolo‐ [1,5‐c]thieno[3,2‐e]pyrimidines. The required thienopyrimidine derivatives were synthesized from 2‐amino‐3‐triazolyl‐ and 2‐amino‐3‐tetrazolylthiophenes by acylation, followed by dehydrative cyclization.
Synthesis of certain exocyclic thiazole nucleosides related to tiazofurin. Formation of a unique acycloaminonucleoside
Authors: Sanghvi Yogesh S. , Larson Steven B. , Robins Roland K. , Revankar Ganapathi R. , Gupta Pranab K. , George Rose D. , Dalley N. Kent 
Published: April 2009

AbstractSeveral thiazole nucleosides structurally related to tiazofurin (1) and ARPP (2) were prepared, in order to determine whether these nucleosides had enhanced antitumor/antiviral activities. Ring closure of 1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)thiourea (4) with ethyl bromopyruvate (5a) gave ethyl 2‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosylamino)thiazole‐4‐carboxylate (6a). Treatment of 6a with sodium methoxide furnished methyl 2‐(β‐D‐ribopyranosylamino)thiazole‐4‐carboxylate (9). Ammonolysis of the corresponding methyl ester of 6a gave a unique acycloaminonucleoside 2‐[(1R, 2R, 3R, 4R)(1‐benzamido‐2,3,4,5‐tetrahydroxypentane)amino]‐thiazole‐4‐carboxamide (7a). Direct glycosylation of the sodium salt of ethyl 2‐mercaptothiazole‐4‐carboxylate (12) with 2,3,5‐tri‐O‐benzoyl‐D‐ribofuranosyl bromide (11) gave the protected nucleoside 10, which on ammonolysis provided 2‐(β‐D‐ribofuranosylthio)thiazole‐4‐carboxamide (3b). Similar glycosylation of 12 with 2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranosyl chloride (13), followed by ammonolysis gave 2‐(2‐deoxy‐β‐D‐ribofuranosylthio)thiazole‐4‐carboxamide (3c). The structural assignments of 3b, 7a, and 9 were made by single‐crystal X‐ray analysis and their hydrogen bonding characteristics have been studied. These compounds are devoid of any significant antiviral/antitumor activity in vitro.
Synthesis of 3‐(2‐Aminoethyl)pyrrole Derivatives
Authors: Demopoulos Vassilis J. 
Published: April 2009

Abstract3‐(2‐Di‐n‐propylaminoethyl)pyrrole (1a) was prepared in good yield by reduction of pyrrole‐3‐(N,N‐di‐n‐propylglyoxamide) (9) with lithium aluminum hydride. 3‐(2‐Di‐n‐propylaminoethyl)‐5‐acetylpyrrole (1b) was prepared by first acetylation of 1‐p‐toluenesulfonyl‐3‐(2‐di‐n‐propylaminoethyl)pyrrole (6) followed by hydrolysis of the p‐toluenesulfonyl substituent. The starting material 6 was prepared by homologation of 1‐(p‐toluenesulfonyl)pyrrole‐3‐carboxaldehyde (3) to the corresponding acetaldehyde followed by reductive amination of the latter.
17O NMR investigation of acetyl and formylthiophenes, furans and pyrroles
Authors: Boykin David W. , Rhodes R. Allen 
Published: April 2009

AbstractThe 17O nmr chemical shifts of 20 acetyl and formylthoiphenes, furans, and pyrroles are reported. The chemical shifts qualitatively correlate with the electronic character of the heterocyclic rings. The effect of steric factors are noted for the 17O chemical shifts of alkyl substituted acetylthiophenes and for N‐methylpyr‐roles.
A practical synthesis of ethyl 1,2,4‐triazole‐3‐carboxylate and its use in the formation of chiral 1′,2′‐seco‐nucleosides of ribavirin
Authors: Vemishetti Purushotham , Leiby Robert W. , Abushanab Elie , Panzica Raymond P. 
Published: April 2009

AbstractA practical and efficient synthesis of ethyl 1,2,4‐triazole‐3‐carboxylate (6a, R' = H) from ethyl carboethoxyformimidate hydrochloride (7) is described. Alkylation of this heterocycle with the chloromethyl ethers of 1,3‐O‐dibenzylbutane‐1,2R,3S‐triol (8a) and 1,3,4‐O‐tribenzylbutane‐1,2R,3S,4‐tetrol (8b), followed by conversion of the ester function to the amide and deprotection, furnished the chiral 1′,2′‐seco‐nucleosides of ribavirin, 11a and 11b, respectively.
Synthese D'isoquinoleinediones‐5,8 apparentees a la mimocine
Authors: Croisy‐Delcey Martine , Huel Christianne , Bisagni Emile 
Published: April 2009

AbstractL'anhydride selenieux transforme la méthyl‐1 diméthoxy‐5,8 isoquinoléine en donnant la formyl‐1 diméthoxy‐5,8 isoquinoléine. Si l'oxydation de la [(méthyl‐2 propanediol‐1,3) aminométhyl‐2]‐1 diméthoxy‐5,8 isoquinoléine, dérivée de ce dernier composé, par le nitrate de cerium ammoniacal, ne fournit pas le quinone attendue, au contraire et dans les měmes conditions les acylaminométhyl‐1 diméthoxy‐5,8 isoquinoléines, permettent de préparer les quinones apparentées à la mimocine.L'aminométhyl‐1 diméthoxy‐5,8 isoquinoléine intermédiaire est préparée en introduisant directement la fonction aminométhyle protégée par le groupement phtalimido.
Acetylenchemie. 9. Mitt. Anellierte imidazole aus N‐propinylamid‐vorstufen
Authors: Reisch Johannes , Scheer Mathias 
Published: April 2009

Abstract2‐(N‐Formyl‐N‐prop‐2′‐inyl)‐aminopyridin cyclisiert in siedender Ameisensäure zum 3‐Methylimidazo‐[1,2‐a]pyridin, wobei 3‐Methylen‐2H‐imidazo[1,2‐a]pyridin als Intermediat auftritt. Unter den gleichen Bedingungen bildet sich aus dem 1,3‐Diprop‐2‐inylpyrimido[4,5‐b]chinolin‐2,4‐dion das 1‐Methylimidazo‐[1,2‐a]chinolin‐4‐carbonsäure‐N‐prop‐2′‐inylamid und aus dem 1‐Prop‐2′‐inylbenzo[b][1,8]naphthyridin‐2‐on als neues Ringsystem das 1‐Methyl‐benzo[b]imidazo[1,2,3‐ij][1,8]naphthyridin‐4,7‐dion.
Dibenzo[d,h][1,3,6,7,2]dioxadithiasilonin: Synthesis and characterization
Authors: Pastor Stephen D. , Denney Dorothy Z. 
Published: April 2009

AbstractThe reaction of 2,4‐di‐t‐butylphenol, 4, with sulfur monochloride gave the trithiobisphenol 5 rather than the expected dithiobisphenol 7. The thiol 6 was obtained by the reduction of 5 with zinc under acidic conditions. The dithiobisphenol 7 was prepared by the oxidative coupling of 6 with iodine under alkaline conditions. The dibenzo[d,h][1,3,6,7,2]dioxadithiasilonin 8 was prepared by the reaction of 7 with dichlorodimethylsilane using triethylamine as an acid acceptor. No change was observed in the 1H nmr spectrum of 8 upon cooling to −55°, which suggests that the ΔG* for ring inversion is less than the corresponding eight‐membered dibenzo[d,g][1,3,2]dioxasilocin and dibenzo[d,g][1,3,6,2]dioxathiasilocin 1 and 2, respectively. The spectral data and elemental analysis are fully in accord with the nine‐membered silonin structure.
Electron impact mass spectrometry of 3‐hydroxy‐3,4,5,6‐tetrahydro‐2H‐[1]benzoxocines. A comparison with the behaviour of isomeric 2‐hydroxymethyl‐2,3,4,5‐tetrahydro‐[1]‐benzoxepines and 1,2‐epoxy‐5‐(2‐hydroxyphenyl)pentane
Authors: Bravo Pierfrancesco , Ticozzi Calimero , Pelli Beatrice , Traldi Pietro 
Published: April 2009

AbstractThe mass spectrometric behavior of 3‐methyl‐3‐hydroxybenzoxocines has been studied in detail by means of linked scans and mass analyzed ion kinetic energy spectrometry. The structure of the molecular ion and the fragmentation processes are strictly related to the structure of the neutral moieties.The possible isomerization of 3‐hydroxy‐10‐methoxy‐3‐methyl‐3,4,5,6‐tetrahydro‐2H‐[1]benzoxocine to 2‐methyl‐2‐[3‐(3′‐methoxy‐2′‐hydroxy)phenyl]pentyloxirane and to 2‐hydroxymethyl‐9‐methoxy‐2‐methyl‐2,3,4,5‐tetrahydro[1]benzoxepine is investigated.
Regioselectivity in the 1,3‐dipolar cycloaddition reaction of unsymmetric pyridinium dicyanomethylides with dimethyl acetylenedicarboxylate and methyl propiolate: An example of dipole‐dipole control of regioselectivity?
Authors: Matsumoto Kiyoshi , Ikemi Yukio , Konishi Hideyuki , Shi Xiao‐Lan , Uchida Takane , Aoyama Kinuyo 
Published: April 2009

AbstractA study of the cycloaddition behavior of a series of unsymmetric pyridinium dicyanomethylides with dimethyl acetylenedicarboxylate and methyl propiolate has been carried out. The 1,3‐dipolar cycloaddition proceeds in good yield with high regioselectivity to produce the corresponding indolizines and 1:1 adducts. The reactions of isoquinolinium dicyanomethylide follow frontier orbital predictions. In contrast, polar 3‐substituted pyridinium dicyanomethylides gave predominantly the corresponding 8‐isomers regardless of the substituents. The results can be explained by dipole‐dipole interactions.
An unusual ring transformation: Reaction of phenyl 4‐chromone‐3‐sulfonate with methyl 3‐aminocrotonate
Authors: Löwe Werner , Jeske Peter , Kradepohl Anneliese 
Published: April 2009

AbstractThe novel benzoxathiinopyridines 8 and 9 were synthesized by ring transformation of phenyl 4‐chromone‐3‐sulfonate (1) with methyl 3‐aminocrotonate (2). The structures of 8 and 9 were determined by spectroscopic methods and the reaction courses for the formation of these compounds are discussed.
Synthesis of 3‐aryl‐6H‐isoxazolo[3,4‐d]pyrazolo[3,4‐b]pyridines and 3‐aryl‐6H‐isoxazolo[5,4‐d]pyrazolo[3,4‐b]pyridines
Authors: Shutske Gregory M. , Huger Francis P. 
Published: April 2009

AbstractThe synthesis and characterization of a number of 3‐aryl‐6H‐isoxazolo[3,4‐d]pyrazolo[3,4‐b]pyridines and 3‐aryl‐6H‐isoxazolo[5,4‐d]pyrazolo[3,4–6]pyridines from common precursors, 5‐benzoyl‐4‐chloro‐1H‐pyrazolo‐[3,4‐b]pyridines, has been described. The structures were determined by unambiguous chemical synthesis and by isolation and 13C nmr analysis of some key, isolated, intermediates. The ability of these compounds to displace [3H]flunitrazepam from CNS binding sites was also observed.
Novel synthesis of dianthalexin (phytoalexin) analogues preparation
Authors: Hauteville M. , Ponchet M. , Ricci P. , Favre‐Bonvin J. 
Published: April 2009

AbstractTwo phytoalexins, previously isolated from carnation infected by Phytophthora parasitica D., were synthesized: 2‐phenyl‐7‐hydroxy‐4H‐3,l‐benzoxazin‐4‐one (Dianthalexin) and 2‐(2‐hydroxybenzoyl)‐amino‐4‐methoxybenzoic acid (Dianthramide A). The first one was obtained by using potassium t‐butoxide in dimethylformamide to prevent its heterocycle opening. Five novel other analogous compounds were also prepared.
Synthesis of some novel 7‐substituted quinolonecarboxylic acids via nitroso and nitrone cycloadditions
Authors: Ziegler Carl B. , Bitha Panayota , Lin Yang‐I 
Published: April 2009

Abstract1‐Ethyl‐6‐fluoro‐7‐hydroxylamino‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid 7 can be either oxidized to the corresponding nitroso intermediate 8 or converted to the methylene nitrone 9. Both intermediates form cycloaddition products with selected dienes and olefins respectively. Also, the preparation of 1‐ethyl‐6‐fluoro‐7‐(hexahydro‐2‐methyl‐5H‐pyrrolo[3,4‐d]isoxazol‐5‐yl)‐3‐quinolinecarboxylic acid 5 via a nitrone cycloaddition is presented.
Cyclocondensation of 3‐amino‐2‐hydrazino‐4(3H)‐pyrimidinones with dimethyl acetylenedicarboxylate. Formation of 1‐amino‐2,6‐dihydro‐2,6‐dioxo‐1H‐pyrimido[1,2‐b][1,2,4]triazine‐3‐acetic acid esters
Authors: Bitha Panayota , Hlavka Joseph J. , Lin Yang‐I 
Published: April 2009

Abstract[(1‐Amino‐6‐hydroxy‐2(1H)‐pyrimidinylidene)hydrazone]butanedioic acid dimethyl esters 3, formed from 3‐amino‐2‐hydrazino‐4(3H)‐pyrimidinones and dimethyl acetylenedicarboxylate in acetic acid at room temperature, underwent a facile, thermal rearrangement to 1‐amino‐2,6‐dihydro‐2,6‐dioxo‐1H‐pyrimido‐[1,2‐b]‐[1,2,4]triazine‐3‐acetic acid methyl esters 6 in hot acetic acid.
A new heterocyclic structure. The [1,2,3]triazolo[1,5‐d][1,2,4]triazine
Authors: Bianchi Mario , Butti Alina , Perronnet Jacques 
Published: April 2009

AbstractThe hydrazone derivatives of 4‐benzoyl‐1,2,3‐triazole can easily be cyclised by reaction with various organic reagents (ortho esters, aldehyde and ketone compounds, phosgene, etc) which result in the incorporation of the introduced reagent's carbon atom into the new six membered ring. The newly created C‐N bond of the resulting [1,2,3]triazolo[1,5‐d][1,2,4]triazines displays a particular sensitivity due to the electron attracting effect of the triazole ring. Some mechanistic considerations are proposed to account for the observed results.
A facile synthesis of 3‐amino‐5‐substitutedaminoisothiazole‐4‐carboxylic acid derivatives
Authors: Shishoo C. J. , Devani M. B. , Ananthan S. , Bhadti V. S. , Ullas G. V. 
Published: April 2009

AbstractA facile, general and one‐pot method for the preparation of 3‐amino‐5‐substituted‐aminoisothiazole‐4‐carboxylic acid derivatives, in high yields, by the aminative cyclization of 3‐amino‐3‐mercaptoacrylonitriles is described.
Lanthanide(III) ion catalyzed reaction of ammonia and nitriles: Synthesis of 2,4,6‐trisubstituted‐s‐triazines
Authors: Forsberg John H. , Spaziano Vincent T. , Klump Stephen P. , Sanders Kathleen M. 
Published: April 2009

AbstractLanthanum and yttrium trifluoromethanesulfonates at 1 mole % concentration, have been found to catalyze a reaction between ammonia and aromatic nitriles to yield symmetrically substituted 2,4,6‐triaryl‐s‐triazines. The generally high yields and relatively mild reaction conditions of this procedure suggest it as an alternative to other aromatic nitrile cyclotrimerization reactions. Of the aliphatic nitriles studied, acetonitrile and cyclopropanecarbonitrile gave good yields of triazine, propionitrile and butyronitrile gave significantly reduced yields of triazines 3b and 3c respectively. Rearrangement of 3a and 3b to alkylated‐4‐aminopyrimidines was observed.
A convenient preparation of 3‐methyl‐3,4‐dihydro‐2(1H)‐quinazolinone
Authors: Golec Frederick A. , Reilly Laurence W. 
Published: April 2009

Abstract3‐Methyl‐3,4‐dihydro‐2(1H)‐quinazolinone (5) can be prepared in good yield and quality from o‐nitrobenzyl chloride (1). The three‐step sequence requires no purification of intermediates or final product.
A new synthetic route to 4,6‐diarylpyridazinones and some of their derivatives
Authors: Coudert P. , Couquelet J. , Tronche P. 
Published: April 2009

AbstractA novel approach to the titled ring system starting from conveniently available chalcones 1 is proposed. It involves a catalysed exchange of hydrogen cyanide between acetone cyanohydrin and 1. The resulting γ‐ketonitriles 2 give the expected 4,6‐diarylpyridazinones 4 and 5 via hydrolysis and cyclisation by hydrazine. The action of phosphorus oxychloride on 5 followed by that of amines provides aminopyridazines 7.
Amination of 4‐nitro‐ and 4‐cyanopyridazines by liquid ammonia/potassium permanganate
Authors: Marcelis Antonius T. M. , Tondijs Hanna , Van Der Plas Henk C. 
Published: April 2009

Abstract4‐Nitro‐3‐R1‐6‐R2‐pyridazines (1) (a, R1 = R2 = 2‐pyridyl; b, R1 = H, R2 = phenyl; e, R1 = H, R2 = p‐methoxyphenyl; d, R1 = R2 = H) are aminated by liquid ammonia/potassium permanganate to the corresponding 5‐amino‐4‐nitropyridazines 3a‐d. The 4‐cyano‐3‐R1‐6‐R2‐pyridazines 4a,b are only aminated in the presence of potassium amide in liquid ammonia/potassium permanganate to give the 5‐amino‐4‐cyanopyridazines 6a,b. The 5‐amino‐4‐nitropyridazines 3a,b,d are converted to the 4,5‐diaminopyridazines 7a,b,d by reduction over a Pd/C catalyst. Reaction of 7b with glyoxal leads to 5‐phenylpyrazino[2,3‐d]pyridazine (8b).