bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the syntheses of heterocyclic and natural products. Part 979. Attempted asymmetric synthesis of yohimbol by photocyclization of the enamide
Authors: Kametani Tetsuji , Takagi Nanami , Kanaya Naoaki , Honda Toshio , Fukumoto Keiichiro 
Published: March 2009

AbstractAn asymmetric synthesis of yohimbane alkaloid has been attempted by the photolysis of the corresponding enamide (3) as a key reaction.
New tetracyclic ring systems. Synthesis of 1H‐oxazolo[5,4,3‐kl]phenothiazines and [1,4]oxazino[2,3,4‐kl]phenothiazines
Authors: Nodiff Edward A. , Taunk Prakash C. 
Published: March 2009

Abstract1‐Hydroxyphenothiazine was converted to 1H‐oxazolo[5,4,3‐kl]phenothiazin‐1‐one, 1H‐oxazolo[5,4,3‐kl]‐phenothiazine‐1‐thione,[1,4]oxazino[2,3,4‐kl]phenothiazin‐1(2H)one and [1,4]oxazino[2,3,4‐kl]phenothiazine‐1,2‐dione. Also prepared from 1‐hydroxyphenothiazine were the N‐chloroacetyl derivative, the O‐chloroacetyl derivative, the N,O‐di(chloroacetyl) derivative and the sulfoxide.
Synthèse spécifique de pyrimidines. Formation conccurentielle de pyrimidines et de triazépines
Authors: Mérour J. Y. 
Published: March 2009

AbstractLa condensation d'ortho aminoesters avec l'éthoxyméthylène cyanoacétate d'éthyle conduit à des composés du type ortho (cyano‐2′ éthoxycarbonyl‐2′) vinylaminoester 1. Iis subissent un déplacement nucléofuge du groupement cyanoacétate d'éthyle sous Taction de l'hydrazine ou de la méthylhydrazine pour donner exclusivement des composés de la famille des pyrimidines 3 ou 4. Ces pyrimidines peuvent ětre mono ou diacétylées. Par contre, l'action de Torthoformiate d'éthyle ou de l'orthoacétate d'éthyle sur divers ortho aminohydrazides donne un mélange de pyrimidines et de triazépines.
Synthesis of Δ1[9]‐ and/or Δ8[9]‐dehydroindolizidines and related compounds
Authors: Miyano Seiji , Fujii Shinichiro , Yamashita Osamu , Toraishi Naoko , Sumoto Kunihiro 
Published: March 2009

AbstractA facile synthesis of Δ1[9]‐ and/or Δ8[9]‐dehydroindolizidine and related compounds, consisting of dry distillation of γ‐(N‐2‐piperidinonyl)butyric acid over soda‐lime, is described. Reductions of these dehydroindolizidines and stereochemistry of 1‐methylindolizidine are also described.
Convenient preparation of 2‐benzoxazolinones with 1,1‐carbonyldiimidazole
Authors: Nachman Ronald J. 
Published: March 2009

AbstractA convenient and general preparation of 2‐benzoxazolinones from 2‐aminophenols with 1,1‐carbonyldiimidazole is described. Included is a discussion of a much improved synthesis of the reproductive‐stimulant 6‐methoxy‐2‐benzoxazolinone (6‐MBOA) that utilizes this procedure.
Solvolysis of di‐2‐pyridylketone methiodide
Authors: Williams R. L. , Neergaard Sandra 
Published: March 2009

AbstractDi‐2‐pyridylketone methiodide undergoes a facile nucleophilic substitution reaction with various alcohols followed by subsequent cleavage and elmination of pyridinium methiodide and the correspoing picolinates.
Oxydation d'hydrazones par le bioxyde de plomb: Nouvelles synthèses d'oxadiazoles‐1,3,4 et de dérivés de l'amino‐4 triazol‐1,2,4 one‐5
Authors: Milcent René , Barbier Géo 
Published: March 2009

AbstractL'oxydation des aroylhydrazones d'aldéhydes aromatiques, par le bioxyde de plomb, dans l'acide aceti‐que, constitue une nouvelle méthode d'accés, simple et rapide, aux oxadiazoles‐1,3,4 correspondants. Dans le diméthylformamide, et en presence du měme oxydant, les carbodihydrazones d'aldéhydes aromatiques con‐duisent aux aryl‐3 arylidéneamino‐4 triazol‐1,2,4 ones‐5 correspondantes. Plusieurs mécanismes radicalaires sont proposés.
Synthesis and stereochemical assignment of endo‐7‐phenyl‐2,5‐dioxabicyclo[4.1.0]heptane
Authors: Hobbs Gregory D. , Woodyard James D. , Curtis John R. 
Published: March 2009

AbstractThe synthesis and stereochemical assignment of endo‐7‐phenyl‐2,5‐dioxabicyclo[4.1.0]heptane is reported.The stereochemical assignment was made based on both spectral and chemical data.
Synthesis and characterization of 1H‐benz[f]indole‐4,9‐dione and the related dihydroxy derivative
Authors: Malesani Giorgio , Ferlin Maria Grazia , Masiero Sergio 
Published: March 2009

AbstractDehydrogenation and contemporaneous demethylation of the parent 4,9‐dimethoxy‐5,6,7,8‐tetrahydro‐1H‐benz[f]indole (2) yielded the expected aromatization products 4 and 5 (1H‐benz[f]indole‐4,9‐dione and 4,9‐di‐hydroxy‐1H‐benz[f]indole, respectively).
Synthesis of a novel analog of nalidixic acid: 1‐Ethyl‐1,4‐dihydro‐4‐oxo‐7‐(trifluororaethyl)‐1,8‐naphthyridine‐ 3‐carboxylic acid
Authors: Singh Baldev , Lesher George Y. 
Published: March 2009

AbstractReaction of nalidixic acid (1) with thionyl chloride and subsequent treatment with ethanol gave a mixture of ethyl 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(trichloromethyl)‐1,8‐naphthyridine‐3‐carboxylate (3) and diethyl 1‐ethyl‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3,7‐dicarboxylate (4). Ethyl1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(trichloromethyl)‐1,8‐naphthyridine‐3‐carboxylate (3) was reacted with antimony pentafluoride to afford 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(trifluoromethyl)‐l,8‐naphthyridine‐3‐carboxylic acid (5).
Reaction of substituted sulfenes with N,N‐disubstituted α‐amino‐methyleneketones. I. Synthesis of N,N‐disubstituted cis‐ and trans‐4‐amino‐3,4,5,6,7,8‐hexahydro‐3‐phenyl‐1,2‐benzoxathiin 2,2‐dioxides
Authors: Bargagna Alberto , Bignardi Gaetano , Schenone Pietro , Longobardi Mario 
Published: March 2009

AbstractThe polar 1, 4‐cycloaddition of phenylsulfene (generated in situ from phenylmethanesulfony] chloride and triethylamine) to N, N‐disubstituted (E)‐2‐aminomethylenecyclohexanones I gave in general a mixture of N, N‐disubstituted cis‐ and trans‐4‐amino‐3, 4, 5, 6, 7, 8‐hexahydro‐3‐phenyl‐1, 2‐benzoxathiin 2, 2‐dioxides III and IV, which were separated by column chromatography and whose structural and conformational features were determined from uv, ir and nmr spectral data. In the case of N, N‐diisopropylamino enaminone 1c, the cyclo‐addition took place with elimination of an alkyl group as propene to give the adduct IIIℓ.
Dihydropyridazines. III . Reactions with oxygen
Authors: Baker James , Hedges Winston , Timberlake Jack W. , Trefonas Louis M. 
Published: March 2009

AbstractThe reactions of oxygen with a series of dihydropyridazines have been explored. The primary reaction other than aromatization appears to occur from the 1, 4‐dihydro tautomer. A single crystal x‐ray structure has been determined on the product from the reaction of oxygen with 3, 6‐diphenyl‐4, 4‐dimethyl‐1, 4‐dihydropyridazine.
The chemistry of polycyclic arene imines. II. Photochemistry of phenanthrene 9,10‐imine and of its N‐butyl derivative
Authors: Weitzberg Moshe , Avnir David , Aizenshtat Zeev , Blum Jochanan 
Published: March 2009

AbstractThe uv irradiation of phenanthrene 9, 10‐imine has been shown to give 9H‐tetrabenzo[a, c, g, i]carbazole as the major photo‐product both in argon purged acetone and in dichloromethane. Phenanthrazine, N‐9‐phenanthrenyl‐9‐phenanthrenamine and phenanthrene were formed in smaller quantities. 9‐Phenanthrenamine was found to be a minor by‐product. N‐Butylphenanthrene 9, 10‐imine yielded under similar conditions phenanthrene and N‐butyl‐9‐phenanthrenamine as the only isolable polycyclic compounds. In the presence of air the substituted imine gave mainly 2‐propylphenanthro[9, 10‐d]oxazole.
Effect of metal ions in organic synthesis. Part XIV. A mild, simple, and convenient method for the synthesis of 1‐(arylamino)pyrrole derivatives by copper(II) ion‐catalyzed reaction of (arylazo)alkenes and 1,3‐dicarbonyl compounds
Authors: Attanasi Orazio , Bonifazi Paola , Buiani Franca 
Published: March 2009

AbstractA mild, simple and convenient method for the synthesis of some 1‐(arylamino)pyrrole derivatives by copper(II) ion‐catalyzed reaction of (arylazo)alkenes and 1, 3‐dicarbonyl compounds is reported. These reactions take place under magnetic stirring at room temperature, do not require a strong acid or base, nor expensive or difficultly available reagents, nor even complicated procedures. The synthesis seems to be successfully applicable to different (arylazo)alkenes, 1, 3‐diketones and ß‐ketoesters, and frequently occurs with good yields.
Synthèse d'analogues acycliques de C‐nucléosides
Authors: Babin Fabienne , Dinh Tam Huynh , Igolen Jean 
Published: March 2009

AbstractSynthèse d'analogues acycliques de nucléosides où la chaîne est liée à la base hétérocyclique par une liaison carbone‐carbone. Nous décrivons une méthode directe pour la préparation de dérivés de la guanine et de la s‐triazolo[1,5‐a]pyridine.
Spectrométrie de masse. Fragmentations induites par impact électronique d'amino et de diméthylaminopyrimidines
Authors: Riand J. , Brun J. P. 
Published: March 2009

AbstractLes séquences de fragmentation, induites par impact électronique de trois aminopyrimidines et de quatre dimeéthylaminopyrimidines sont envisagées. Alors que dans le cas des aminopyrimidines la séquence principale de fragmentation correspond à une perte d'acide cyanhydrique, pour les diméthylaminopyrimidines deux séquences prépondérantes sont observées: ‐élimination d'un radical méthyle; ‐élimination de méthylènimine CH2NH. La présence de l'ion HNMe2+− dans le cas de la diméthylamino‐4 pyrimidine permet de différencier ce composé de son homologue en position 2.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (isatoic anhydride). 10. Reactions with ester enolates. Synthesis of 4‐hydroxy‐1‐methyl‐3‐prenyl‐2(1H)‐quinolinones, Crucial intermediates in the synthesis of quinoline alkaloids
Authors: Coppola Gary M. 
Published: March 2009

AbstractN‐Methylisatoic anhydride reacts with the lithium enolates of esters to produce β‐ketoesters 4 in nearly quantitative yield. Thermal cyclization of these relatively unstable intermediates afford the corresponding 3‐substituted‐4‐hydroxy‐1‐methyl‐2(1H)‐quinolinones (5) in good yields. The reaction of the lithium enolate of 5‐methyl‐4‐hexenoic acid ethyl ester (14) with various nuclear substituted isatoic anhydrides gives 4‐hydroxyl‐methyl‐3‐prenyl‐2(1H)‐quinolinones 8, 9, and 18 which are highly desirable intermediates in the synthesis of a variety of quinoline alkaloids. Treatment of 18 with DDQ furnishes oricine in 73% yield.
Ring closure reactions involving 1‐hydrazinophthalazine. Reactions with 1,2,4‐tricarbonyl and 1,3‐dicarbonyl compounds
Authors: Amer Adel , Zimmer Hans 
Published: March 2009

AbstractAnnelation reactions of six‐membered rings to 1‐hydrazinophthalazine, 1, were investigated. With aroyl‐(acyl)pyruvates, 2, the desired system was obtained. It was found that the course of the reaction depends on the reaction condition as well as the substituted pyruvates. Thus, 3‐(2‐oxo‐2‐substituted ethyl)‐4H‐as‐triazino‐[3,4‐a]phthalazin‐4‐one, 4, was the product when 1 reacted with 2 in alcoholic medium. The side chain tauto‐merism of 4 was studied by using ir, 1H‐nmr, and ms spectral methods. When 1 hydrochloride instead of 1 was reacted with 2, 3‐ethoxycarbonyl‐s‐triazolo[3,4‐a]phthalazine, 6, was the major product. The reaction of 1 with benzoylacetone in ethanol afforded the hydrazalone, 9. By ir, 1H‐nmr, and 13C‐nmr methods it was shown that in solution it is inolved in an enhydrazine‐hydrazone as well as a ring‐chain tautomerism. Compound 9 upon the action of PPA underwent dehydrative cyclization to 3‐methyl‐s‐triazolo[3,4‐a]phthalazine, 10, and 3‐methyl‐5‐phenyl‐1‐(l‐phthalazinyl)pyrazole, 7. The reaction of 1 with ethyl phenylpropiolate in ethanol was reported by others to give 1‐(1‐phthalazinyl)‐3‐phenyl‐5‐pyrazolone, 8. Upon reinvestigation of this reaction it is shown that the product actually is ethyl β‐(1‐phthalazinylhydrazono)benzenepropanoate, 11. Attempts to synthesize 8 were unsuccessful by this method. In the reaction of 1 with ethyl benzoylacetate the expected hydralazone 11 was easily formed which upon reaction with PPA yielded the desired species 8.
Condensed 1,2,4‐triazines. Regioselective condensations with benzo[h]quinoline‐5,6‐dione
Authors: Eid Mohga M. , Badawy Mohamed A. , Ibrahim Yehia A. 
Published: March 2009

AbstractBenzo[h]quinoline‐5,6‐dione condenses with semicarbazide and its derivatives regioselectively at the 6‐position and the products cyclize into the corresponding condensed 1,2,4‐triazines. Reactions of the obtained triazines with a variety of reagents are described.
Imdazole systems. I. Imidzo[2,1‐b][1,3,5]benzothiadiazepine derivatives as potential antipsychotic agents
Authors: Vecchia Laurence Delia , Dellureficio James , Kisis Biruta , Vlattas Isidoros 
Published: March 2009

AbstractImidazo[2,1‐b][1,3,5]benzothiadiazepine 3 constitutes a novel ring system, and its analogs 3a‐i were synthesized to investigate their potential antipsychotic activity. The synthesis of the ring system was achieved by reaction of 2‐aminophenylthioimidazoles 7 with phosgene or thiophosgene and by ring closure of the 1‐[2‐(2‐imidazolyl)thiophenyliminocarbonyl]‐1‐piperazines 13. An efficient method for the conversion of thioureas 8, 12 to guanidine 3a via the corresponding cyanothioamidines 11, 14 was developed.
Assignment of the 1H‐ and 13C‐NMR spectra of phenanthro[1,2‐b]thiophene through the concerted application of two‐dimensional NMR spectroscopic techniques
Authors: Martin Gary E. , Smith Stanford L. , Layton W. John , Willcott M. Robert , Iwao Masatomo , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractTwo‐dimensional nmr spectroscopy, by virtue of its second frequency domain which permits the segregation of spectral information along two frequency axes, considerably simplifies many assignment problems and facilitates others which may be impossible using conventional nmr methodology. A compound which falls into the latter category of assignment problem is phenanthro[1,2‐b]thiophene. The assignment of the 1H‐ and 13C‐nmr spectra of phenanthro[1,2‐b]thiophene are, however, reported through the concerted application of two‐dimensional nmr techniques. Experiments utilized in making the assignments included: auto‐correlated homonuclear (COSY) two‐dimensional spectroscopy; heteronuclear two‐dimensional J‐resolved spectroscopy; proton‐carbon chemical shift correlation two‐dimensional spectroscopy; and two‐dimensional 13C‐13C double quantum coherence spectroscopy.
A new synthesis of symmetrical 2,5‐diaryl‐1,3,4‐thiadiazoles
Authors: Mazzone Gioacchino , Puglisi Giovanni , Bonina Francesco , Corsaro Antonino 
Published: March 2009

AbstractTreatment of aromatic aldehydes with sulfur and hydrazine hydrate in the ratio 1:2:3, respectively, under the Willgerodt conditions affords the title compounds in excellent yields and in a good state of purity. Under the same conditions 2‐chloro and 2,6‐dichlorobenzaldehyde yield 3H‐1,2‐benzodithiole‐3‐thione and bis‐(2,6‐dichlorobenzyl)tetrasulfide, respectively.
Synthesis of the metabolites of oxapadol, a new non‐narcotic analgesic agent
Authors: Guerret Patrick , Ancher Jean‐François , Langlois Michel 
Published: March 2009

AbstractDifferent metabolites (2‐7) of oxapadol 1 were carried out from 3 by known methods. Their acidic hydrolysis provided compounds 4 in which the dioxolane moiety was opened. The reaction of glycerol with compounds 3 gave the dioxolane derivatives 5 which have a hydroxymethyl group and which (R = H) gave by oxidation the carboxylic acid 7. From 3 (R = H), the hydroxy acid 6 has been also prepared.
The synthesis of 1,4‐ethano‐1,2,3,4‐tetrahydroisoquinolines as rigid analogues of adrenergic agents
Authors: Muellner Frank W. , Bauer Ludwig 
Published: March 2009

AbstractThe Diels‐Alder addition of benzyne and 4,5‐dimethoxybenzyne to 1‐(2‐trans‐phenylvinyl)‐2‐pyridone and 1‐benzyl‐3‐benzyloxy‐2‐pyridones provided members of the 1,4‐etheno‐3‐oxo‐1,2,3,4‐tetrahydroisoquinoline system. Catalytic reduction of these adducts yielded the corresponding tricyclic lactams. Lithium aluminum hydride reduction of these lactams produced a number of 1,4‐ethano‐1,2,3,4‐tetrahydroisoquinolines.
The synthesis of 4H‐imidazo[5,1‐c][1,4]benzothiazine derivatives
Authors: Fryer R. Ian , Lauer Rudolph F. , Trybulski Eugene J. , Vitone Stephen , Walser Armin , Zenchoff Gladys 
Published: March 2009

AbstractA facile synthesis of the 4H‐imidazo[5,1‐c][1,4]benzothiazine ring system is described. The synthesis utilized the annulation of an imidazole ring onto a 2H‐1,4‐benzothiazin‐3(4H)‐one via the addition of the anion of ethyl isocyanoacetate. Methods for the functionalization of the 1‐, 3‐, 4‐, and 5‐positions of the ring system are presented.
Reaction of acetylenic ketones with hydrazine derivatives. Synthesis of hydroxypyrazoles
Authors: Al‐Hajjar Farouk S. , Sabri Salim S. 
Published: March 2009

AbstractAroylphenylacetylenes Ia‐c react with (‐butyl hydrazinecarboxylate (IIa) and 2‐furylhydrazide (IIb) to give the corresponding hydroxydihydropyrazole derivatives IVa‐f. This cyclic structure is supported by chemical transformations. Thus, when compounds IVa‐c are heated with acetic anhydride, they yield the corresponding 5‐aryl‐1‐(t‐butoxycarbonyl)‐3‐phenylpyrazoles Va‐c which, upon hydrolysis with methanolic potassium hydroxide, produce the corresponding 5(3)aryl‐3(5)phenylpyrazoles VI. Spectroscopic data also confirm the suggested cyclic structure IV.
Heterocyclen aus α‐nitroolefinen. X . Verseifung von 3‐pyrrolcarbonsäureestern mit acetessigsäure‐ und malonsäurederivaten als stickstoffsubstituenten
Authors: Boberg Friedrich , Garburg Karl‐Heinz , Görlich Karl‐Joachim , Pipereit Eberhard , Ruhr Maria 
Published: March 2009

AbstractBei der alkalischen Verseifung der N‐substituierten 3‐Pyrrolcarbonsäureester 7, 9, 12, die auch am Stickstoffsubstituenten eine verseifbare Gruppe haben, reagiert bevorzugt die Estergruppe am Heterocyclus.
Mass spectrometry and chemical synthesis. The case of some substituted Spiro[1,3‐benzodioxole‐2,1′‐cyclohexanes]
Authors: Podda Gianni , Fadda Anna Maria , Maccioni Anna Maria , Pelli Beatrice , Traldi Pietro 
Published: March 2009

AbstractThe electron impact mass spectrometric behaviour of some substituted spiro[1,3‐benzodioxole‐2,1′‐cyclohexanes] has been studied in detail with the aid of linked scans and exact mass measurements. Mass spectrometry has proved to be a valid tool in the structural characterization of the different couples of isomers.
Carbon 13 NMR spectra of pyridylbenz‐X‐azoles
Authors: Savarino Piero , Carpignano Rosarina , Viscardi Guide , Barni Ermanno , Ferrero Giovanni 
Published: March 2009

AbstractThe 13C nmr spectra of a series of pyridylbenzimidazoles and benzoxazoles and of their quaternary salts have been determined. The mutual effects of the two heterocyclic systems and the effect of the quaternization have been discussed. The results evidence the existence of some interactions between benzimidazole and pyridine moieties.
Reaction of 2, 2′‐dithiodianiline with 2‐alkyl‐1, 3‐diketones. Synthesis and chemical behaviour of some 2‐acyl‐2h‐1, 4‐benzothiazines
Authors: Trapani Giuseppe , Latrofa Andrea , Reho Antonia , Liso Gaetano 
Published: March 2009

AbstractThe reactions of 2, 2′‐dithiodianiline 1 with 2‐alkyl‐1, 3‐diketones 2a‐d have been employed in order to synthesize 2‐acyl‐2H‐1, 4‐benzothiazines. In the cases of 2a, b the expected 2‐acyl‐2H‐1, 4‐benzothiazines, i.e. 3a, b were obtained, whereas the reactions of 1 with the 1, 3‐diketones 2c, d afforded the α‐ketosulfide 12 and the 1, 4‐benzothiazine 17, respectively. The products 3a, b underwent the hydrolytic C2‐C3 bond cleavage of the thiazine nucleus to give the α‐ketosulfides 6 and 11, respectively. Such an hydrolytic process explains the formation of the compound 12 in the reaction of 1 with 2c. The formation of 17 in the case of 2d is considered to be formed through a rearrangement involving the 1, 3‐sulfur shift of the preformed 1, 4‐benzothiazine 3d.
The first synthesis of thieno[c]isoquinolines and an improved synthesis of phenanthridine and thieno[c]quinolines through pd(0) catalyzed coupling of ortho‐formylarylboronic acids with functionalized aryl halides
Authors: Yang Youhua , Hörnfeldt Anna‐Britta , Gronowitz Salo 
Published: March 2009

AbstractAll three isomeric hitherto unknown thieno[c]isoquinolines have been synthesized in high yields by the Pd(0)‐catalyzed coupling of 2‐formylbenzeneboronic acid with t‐butyl‐N‐(ortho‐halothienyl)carbaniates. When 2‐bromoacetanilide, instead of 2‐bromoaniline, was coupled with orth‐formylarylboronic acids under Pd‐catalysis, phenanthridine and thieno[c]quinolines were obtained in improved yields.Total assignments of 1H nmr spectra of thieno[c]isoquinolines and thieno[c]quinolines are reported. Assignments are based on high resolution 300 MHz 1H nmr spectra, two‐dimentional 1H‐13C chemical shift correlation spectra and one‐dimentional INADEQUATE 13C nmr spectroscopy.
Synthesis of N‐[4‐[2‐(2,4‐Diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)‐ethylamino]benzoyl]‐L‐glutamic acid. An acyclic analogue of 5,6,7,8‐tetrahydrofolic acid
Authors: Kelley James L. , Mclean Ed W. 
Published: March 2009

AbstractThe synthesis of N‐[4‐[2‐(2,4‐diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)ethylamino]benzoyl]‐L‐glutamic acid (2), a two carbon analogue of 5‐DACTHF (1) and an acyclic analogue of 5,6,7,8‐tetrahydrofolic acid, is reported. The pyrimidinylacetaldehyde diethyl acetal 3, which was prepared in 2‐steps from 2‐chloro acetaldehyde diethyl acetal, was converted to 2 in four steps. Compound 2 was less cytotoxic toward Detroit 98 or L cells than 5‐DACTHF (1).
4‐ and 5‐trifluoromethylimidazoles. Novel cyclization of trifluoroacetylated aldehyde dimethylhydrazones
Authors: Kamitori Yasuhiro , Hojo Masaru , Masuda Ryōtichi , Ohara Seiji , Kawasaki Kazuyoshi , Kawamura Yoshihiko , Tanaka Masakazu 
Published: March 2009

AbstractThermally induced cyclization reaction of trifluoroacetylated arylaldehyde dimethylhydrazones 1 in refluxing toluene afforded 1‐methyl‐4‐aryl‐5‐trifluoromethylimidazoles 2 in good yields. In contrast thermal cyclization of 1 in the presence of silica gel gave regioisomeric 1‐methyl‐4‐trifluoromethyl‐5‐aryl‐imidazoles 5 as major products. These reactions could be extended to the syntheses of related several 1,4,5‐trisubstituted imidazoles.
Furopyridines. X. Synthesis of tricyclic heterocycles, furo[2,3‐b:4,5‐c']‐, furo[3,2‐b:4,5‐c']‐, furo[2,3‐c:4,5‐c']‐ and furo[3,2‐c:4,5‐c']dipyridine
Authors: Shiotani Shunsaku , Morita Hiroyuki 
Published: March 2009

AbstractThis paper describes the synthesis of four tricyclic heterocycles, furo[2,3–6:4,5‐c']‐ (5a), furo[3,2‐b:4,5‐c']‐ (5b), furo[2,3‐c:4,5‐c']‐ (5c) and furo[3,2‐c:4,5‐c']dipyridine (5d). Starting with 2‐formylfuropyridines (1a‐d), β‐(2‐furopyridyl)acrylic acids 2a‐d were obtained by condensing with malonic acid. The acrylic acids were converted to the acid azides by reaction with ethyl chloroformate and the subsequent reaction with sodium azide. Heating of the acid azides at 230–240° with diphenylmethane and tributylamine gave tricyclic pyridinones 3a‐d, which were converted to the respective chloro derivatives 4a‐d by reaction with phosphorus oxychloride. Reduction of the chloro compounds over palladium‐charcoal yielded compounds 5a‐d respectively. All the compounds 2 to 5 were characterized by elemental analysis and spectral data. The H and 13C nmr and electronic spectral features of the furodipyridines were discussed comparing with those of the parent furopyridines.
Synthesis of novel 3‐carboethoxy‐6‐methyl‐4‐oxo‐4H‐pyrimido[1′,2′:5,6]‐[1,3,5]triazino[1,2‐a]benzimidazoles
Authors: Murty M. S. R. , Ramalingam T. , Sattur P. B. 
Published: March 2009

AbstractReaction of 4‐amino‐2‐methylbenzimidazo[1,2‐a][1,3,5]triazines 2 with diethyl ethoxymethylenemalonate afforded 3‐carboethoxy‐6‐methyl‐4‐oxo‐4H‐pyrimido[1′,2′:5,6][1,3,5]triazino[1,2‐a]benzimidazoles 3, a new ring system.
Synthesis of some 4‐substituted and 4,6‐disubstituted dibenzothiophenes
Authors: Katritzky Alan R. , Perumal Subbu 
Published: March 2009

AbstractThe synthesis is described of various 4‐substituted (1) and 4,6‐disubstituted (2) dibenzothiophenes by lithiation reactions. The factors controlling the formation of 4,6‐disubstituted dibenzothiophenes by the lithiation of 4‐methyl‐ and 4‐ethyl‐dibenzothiophene at the 6‐position versus lithiation at the α‐carbon of the 4‐substituent are examined.