bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of some 2,3‐Dihydro‐11bH‐thiazolo[3,2‐d][1,4]benzoxazepin‐5‐(6H)one derivatives. A new heterocyclic ring system
Authors: Torrini Ines , Paradisi Mario Paglialunga , Romeo Aurelio 
Published: May 2009

AbstractCondensation of (S)‐penicillamine methyl or ethyl ester hydrochloride with salicylaldehyde and its C‐5 derivatives, provided the diastereomeric thiazolidine derivatives 1 and 2. The resulting amino function was acylated to afford the amides 3 and 4. Cyclization of the latter led to the 2,3‐dihydro‐11bH‐thiazolo[3,2‐d]‐[1,4]benzoxazepin‐5‐(6H)ones 5 and 6. Conformational data for these heterocyclic compounds are discussed.
Synthesis of triphenyleno[b]thiophenes
Authors: Pratap Ram , Lee Milton L. , Castle Raymond N. 
Published: May 2009

AbstractThe synthesis of all the isomers of triphenyleno[b]thiophenes namely, triphenyleno[l,2‐b]thiophene, triphenyleno[2,1‐b]thiophene and triphenyleno[2,3‐b]thiophene is described.
Synthesis of bisimines of pyrene and dibenz[a,h]anthracene
Authors: Yona Irene , Blum Jochanan 
Published: May 2009

AbstractThe preparation of 3b,4a,7b,8a‐tetrahydro‐4H,8H‐pyreno[4,5‐b:9,10‐b']bisazirine and of 1a,6b,7a,12b‐tetrahydro‐1H,7H‐dibenz[3,4:7,8]anthra[1,2‐b:5,6‐b']bisazirine is described. The corresponding diepoxides were reacted with sodium azide in aqueous acetone and the mixtures of trans‐azido alcohols, so formed, were cyclized by tri‐n‐butylphosphine.
Reaction of phthaloylasparic anhydride with o‐phenylenediamine in solution and spectral analysis of the reaction products
Authors: Yang Chin‐Ping 
Published: May 2009

AbstractThe ring‐opening addition reaction of phthaloylasparic anhydride (I) with o‐phenylenediamine (II) in a solution is affected by the polarity of the solvent used. At the molar ratio of 1:1, I and II undergo a β‐oriented ring‐opening reaction in polar solvents, such as DMF, DMAC, and DMSO; while in weaker polar solvents, such as dioxane and tetrahydrofuran, α‐orientation predominates. By heating in a solvent mixture of DMF and xylene, the ring‐opening products undergo condensation, and are converted into two isomers. One is methanol soluble 3‐phthalimido‐3‐(2)benzimidazolylpropanoic acid (V) resulting from the α‐oriented ring‐opening reaction, the other is the sparingly soluble (in DMF) 2‐phthalimido‐3‐(2)benzimidazolylpropanoic acid (VI) resulting from the β‐oriented ring‐opening reaction. The soluble V can be precipitated as cotton‐like crystals from methanol and chloroform. When treated with acetic anhydride, V and VI are converted to other isomers, namely 3‐phthalimidobenzimidazopyrrolone (VII) and 2‐phthalimidobenzimidazopyrrolone (VIII). The isomers were identified by spectral analysis.
A novel synthesis of theophylline derivatives
Authors: Yoneda Fumio , Koga Ryosuke 
Published: May 2009

AbstractTreatment of 6‐amino‐5‐arylazo‐1,3‐dimethyluracils with ethyl propiolate gave the corresponding Michael‐type adducts, 5‐arylazo‐1,3‐dimethyl‐6‐ethoxycarbonylvinylaminouracils, which on treatment with a mixture of hydrochloric acid and acetic acid caused the acid‐catalyzed rearrangement accompanied with rearrangement to give rise to the corresponding 8‐anilinomethyltheophylline derivatives.In the case that the arylazo group possesses an electron‐releasing substituent such as methoxy, the reaction proceeded in a different way to afford 1,2‐bis(theophyllin‐8‐yl)ethane.The presumable reaction mechanisms for the above purine syntheses were proposed.
Aromatization of aliphatic compounds. VII. Benzofuranones, indoles and oxindoles
Authors: Giannangeli M. , Baiocchi L. 
Published: May 2009

Abstract2(4H)‐5,6‐Dihydrobenzofuranones 3 gave, when treated with pyridine hydrochloride at 200°, the corresponding arylacetic acids 1 in good yields, whereas the aza analogues, the tetrahydrooxindoles 6 gave indoles in poor yields. The oxidation products of 3 (11 and 13) and of 6 (12, 14 and 15) gave, with the same reagent, benzofuranones and oxindoles, respectively, both in good yields.
Imino‐bridged heterocycles. II. Regiospecific synthesis of the 11H‐benzo[5,6]cyclohepta[1,2‐c]pyridin‐6,11‐imine and 5H‐benzo[4,5]cyclohepta[1,2‐b]pyridin‐5,10‐imine systems
Authors: Brenner Daniel G. , Halczenko Wasyl , Shepard Kenneth L. 
Published: May 2009

AbstractRegiospecific synthetic pathways for two of the eight isomeric benzocycloheptapyridinimines have been developed based upon intramolecular acid catalyzed additions between an amine function and an internal olefin. The requisite amines were generated from known tricyclic ketones by ketimine formation followed by sodium borohydride reduction.
Synthesis and xanthine oxidase inhibitory activity of 4,6‐disubstituted 1‐p‐chlorophenylpyrazolo[3,4‐d]pyrimidines
Authors: Senga Keitaro , Robins Roland K. 
Published: May 2009

AbstractSeveral 4,6‐disubstituted 1‐p‐chlorophenylpyrazolo[3,4‐d]pyrimidines were prepared from 4,6‐dichloro‐1‐p‐chlorophenylpyrazolo[3,4‐d]pyrimidine and their xanthine oxidase inhibitory activity were tested in vitro.
On the aromaticity of porphin
Authors: Nudy Louis R. , Coffey Joan C. , Longo Frederick R. , Kim Jean B. 
Published: May 2009

AbstractWe have undertaken a study of the bromination of porphin. We have learned contrary to literature reports, that bromine (in chloroform) attacks porphin preferentially at the meso position and that bromination of this meso monobromoporphin produces a single dibromo product, namely 5, 15‐dibromoporphin. Our results are interpreted in terms of the aromaticity of the different peripheral carbon atoms.
Some sulfur‐containing quinoxalines
Authors: Campaigne E. , Mclaughlin Astley R. 
Published: May 2009

AbstractA series of quinoxalines having oxygen, chlorine or sulfur substituted at the 2‐positio and long‐chain alkyl, alkylthio, arylthio, alkylthioalkyl or arylthioalkyl groups at the 3‐position have been synthesized.
Studies related to the total synthesis of pentostatin. Approaches to the synthesis of (8R)‐3,6,7,8‐tetrahydroimidazo‐[4,5‐d][1,3]diazepin‐8‐ol and N‐3 alkyl congeners
Authors: Baker David C. , Putt Sterling R. , Showalter H. D. Hollis 
Published: May 2009

AbstractA number of synthetic approaches to the (8R)‐3,6,7,8‐tetrahydroimidazo[4,5‐d][1,3]diazepin‐8‐ol ring system (3) of pentostatin (1) are reported. These involve the synthesis of a number of 4‐C‐derivatives of N‐alkyl‐5‐amino‐ and 5‐nitro‐1H‐imidazoles derived from 4‐methyl‐5‐nitro‐1H‐imidazole.
Synthesis of S‐5‐pyrrolo[2,3‐b]pyridinemethyl and S‐5‐ and S‐6‐pyrrolo[2,3‐d]pyridinemethyl derivatives of 5′‐deoxy‐5′‐thioadenosine
Authors: Benghiat Eric , Crooks Peter A. 
Published: May 2009

AbstractReaction of 5‐dimethylaminomethylpyrrolo[2,3‐b]pyridine methiodide or 5‐dimethylaminomethylpyrrolo[2,3‐d]pyrimidin‐4‐one methiodide with 5′‐deoxy‐5′‐S‐thioacetyl‐N6‐formyl‐2′,3′‐O‐isopropylideneadenosine in ethanolic sodium hydroxide solution, followed by deprotection of the resulting thioether in 80% formic acid, afforded 5′‐deoxy‐5′‐(5‐pyrrolo[2,3‐b]pyridinemethylthio)adenosine or 5′‐deoxy‐5′‐[5‐(pyrrolo[2,3‐d]pyrimidin‐4‐one)methylthio]adenosine, respectively. Similarly, the metiodide salt of the iso‐gramine analog, 2‐amino‐6‐dimethylaminomethylpyrrolo[2,3‐d]pyrimidin‐4‐one afforded 5′‐deoxy‐5′‐[6‐(2‐aminopyrrolo[2,3‐d]pyrimidin‐4‐one)methylthio]adenosine.
Synthesis of chalcogeno lactones. II. 3, 4‐dihydro‐1 H‐2‐benzothiin‐3‐one, 3,4‐dihydro‐1H‐2‐benzoselenin‐3‐one and 3,4‐dihydro‐1H‐2‐benzotellurin‐3‐one
Authors: Lemaire Ch. , Luxen A. , Christiaens L. , Guillaume M. 
Published: May 2009

AbstractThe synthesis of 3, 4‐dihydro‐1H‐benzothiin‐3‐one and its selenium and tellurium analogs is reported from o‐bromomethylphenylacetyl chloride and sodium hydrogen chalcogenates, via phase‐transfer catalysis.
Synthesis and spectral studies of 2‐mercapto‐benzimidazole derivatives. II
Authors: Suri O. P. , Khajuria R. K. , Saxena D. B. , Rawat N. S. , Atal C. K. 
Published: May 2009

AbstractThis communication describes synthesis and spectral data of new 2‐mercaptobenzimidazole derivatives.
Synthesis and structural analysis of a 2,5‐diazabicyclo [4.1.0]heptane
Authors: Majchrzak Michal W. , Kotelko Antoni , Lambert Joseph B. 
Published: May 2009

AbstractSynthesis of a new heterocyclic system, 2, 5‐diazabicyclo [4. 1. 0] heptane, substituted on nitrogen, has been achieved by the reaction of the disodium or dipotassium salt of cis‐1, 2‐ (arenesulfonamido) cyclopropane with ethylene bromide. Analysis of the 1H magnetic resonance spectrum demonstrated that this bicyclic system exists as a mixture of interconverting enantiomeric half‐chair conformers.
The synthesis of the monomethylbenzo[2,3]phenanthro‐[4,5‐bcd]thiophenes
Authors: Sugiura Michiharu , Tedjamulia Marvin L. , Tominaga Yoshinori , Castle Raymond N. , Lee Milton L. 
Published: May 2009

AbstractThe synthesis of the potentially mutagenic 1‐methyl‐ (11), 3‐methyl‐ (12), 4‐methyl‐ (21), 5‐methyl‐ (27), 7‐methyl‐ (58), 8‐methyl‐ (61), 9‐methyl‐ (59) and 10‐methylbenzo[2,3]phenanthro[4,5‐bcd]thiophene (60) is reported.
Photoaddition of 2,3‐dimethylmaleic anhydride to selenophthene
Authors: Pacheco D. , Rivas C. , Vargas F. 
Published: May 2009

AbstractAs a continuation of studies carried out in this laboratory [2] on the properties of selenophene and its methyl derivatives as substrates for excited carbonyl compounds and for methylmaleic anhydride derivatives in photosensitized reactions benzo[b]selenophene and selenophthene were tested as well. The latter were found to be inert in oxetane formation but good substrates in photosensitized reactions.
Dipole moments and conformation of 1‐(N,N‐Diaroyl)amino‐1,2,3‐triazoles
Authors: Rodios Nestor A. , Coutsolelos Athanasios G. 
Published: May 2009

AbstractExperimental dipole moments of a number of the title compounds are given and theoretical dipole moments have been calculated by vector addition for all possible conformations. The graphical method has been used to correlate experimental and calculated dipole moments. The more probable conformation in solution of the title compounds and especially of the imide group is proposed.
Synthesis of 4‐amino‐6‐phenyl‐3(2H)‐pyridazinones: A general procedure
Authors: Sircar Ila 
Published: May 2009

AbstractA method for the synthesis of 3,4‐dichloro‐6‐phenylpyridazine 5 was described. The compound 5 was used as an intermediate for the synthesis of a series of 4‐amino‐6‐phenyl‐3(2H)‐pyridazinones.
Thiamorphinans. I
Authors: Sauter Fritz , Stanetty Peter , Hetzl Ernst , Fuhrmann Ferdinand 
Published: May 2009

AbstractThe present paper deals with the synthesis of 5,5a,6,7,8,9‐hexahydro‐5,9a‐iminoethano‐4H‐naphtho[2,1‐b] ‐thiophenes (I) as derivatives of the first of three novel isomeric S‐heterocycles with morphinan‐like structure (“thiamorphinans”).
Displacement reactions of 5‐chloro‐4‐phenylazopyrazoles
Authors: Eid El‐Mohamady E. , Bonner The Late Trevor G. , Lewis David 
Published: May 2009

Abstract3‐Methyl or 3‐phenyl‐5‐chloro‐1‐phenyl‐4‐phenylazopyrazole with primary amines, sodium polysulfide and sodium azide yielded amines, disulfides and 2,4‐dihydropyrazolo[3,4‐d]‐1,2,3‐triazoles respectively. 4‐Amino‐5‐anilino‐1,3‐diphenylpyrazole was also prepared and characterized.
Polycyclic nitrogen compounds. Part II. Tricyclic quinoxalinones and their 4‐ or 6‐aza analogues
Authors: Adegoke E. A. , Alo Babajide 
Published: May 2009

Abstract1,2,3,3a‐Tetrahydro‐9‐nitropyrrolo[1,2‐α]quinoxalin‐4‐one and 7,8,9,10‐tetrahydro‐3‐nitropyrido[1,2‐α]quin‐oxalin‐6‐one (V‐VI) were reduced and deaminated to give new parent tricyclic quinoxalinone skeletons I‐II. The latter compounds were identical with the tricycles obtained by an unambiguous independent synthesis. New 6‐aza‐1,2,3,3a‐tetrahydropyrrolo[1,2‐α]quinoxalin‐4‐one (III) and 4‐aza‐7,8,9,10‐tetrahydropyrido[1,2‐α]‐quinoxalin‐6‐one (IV) were prepared by selective hydrogen transfer reductive cyclisation of esters of N‐(2‐nitro‐3‐pyridyl)pyrrolidine‐2‐carboxylic acid and N‐(2‐nitro‐3‐pyridyl)piperidine‐2‐carboxylic acid (Xb and XIb) respectively.
Some observations concerning the lactonization of 3‐aroylpropionic acids
Authors: Tsolomitis A. , Sandris C. 
Published: May 2009

AbstractThe ease of lactonization of the γ‐keto acids ArCOCH2CH2COOH is shown to depend on the nature of the aryl group: the presence of electron‐releasing substituents on the aryl group results in a more rapid reaction as compared to the presence of electron‐withdrawing substituents. The case of this cyclodehydration reaction is also shown to depend on the reagent used: acetic anhydride‐sulfuric acid is a more drastic reagent than acetic anhydride alone. Acetyl chloride, a reagent of intermediate reactivity in this reaction, is shown to yield easily the corresponding 5‐arylfuran‐2(3H)‐ones in satisfactory yields.
Reaction of substituted sulfenes with N,N‐disubstituted α‐amino‐methyleneketones. II. Synthesis of N,N‐disubstituted cis and trans 4‐amino‐3‐chloro‐3,4,5,6,7,8‐hexahydro‐1,2‐benzoxathiin 2,2‐dioxides, and 4‐amino‐5,6,7,8‐tetrahydro‐1,2‐benzoxathiin 2,2‐dioxides
Authors: Bargagna Alberto , Schenone Pietro , Bignardi Gaetano , Longobardi Mario 
Published: May 2009

AbstractThe polar 1,4‐cycloaddition of chlorosulfene (generated in situ from chloromethanesulfonyl chloride and triethylamine) to N,N‐disubstituted (E)‐2‐aminomethylenecyclohexanones I gave mixtures of N,N‐disubstituted cis and trans 4‐amino‐3‐chloro‐3,4,5,6,7,8‐hexahydro‐1,2‐benzoxathiin 2,2‐dioxides III and IV, except for N,N‐diphenyl enaminone which did not react. Only compounds IV could be separated from these mixtures by silica gel chromatography, with the exception of the piperidino adducts (III + IV)d, from which also IIId could be obtained pure. Compounds IV or mixtures III + IV were dehydrochlorinated with DBN in refluxing benzene to afford N,N‐disubstituted 4‐amino‐5,6,7,8‐tetrahydro‐1,2‐benzoxathiin 2,2‐dioxides V in satisfactory yields. Structural and conformational features of compounds III, IV and V were determined from uv, ir and nmr spectral data.
1,3‐cycloaddition of substituted benzonitrile oxides to aliphatic nitriles. The kinetic effect of substituents
Authors: Beltrame Paolo , Gelli Gioanna , Loi Aldo 
Published: May 2009

AbstractA previous study of the reaction of aromatic nitrile oxides with simple aliphatic nitriles, with the formation of 3,5‐disubstituted 1,2,4‐oxadiazoles, has been extended to a larger number of nitrile oxides. Sixteen new oxadiazole derivatives have been prepared and characterized. Cycloaddition rates have been measured in the temperature range from 50 to 80°. When considering the effect of substituents on the aromatic ring, roughly V‐shaped Hammett plots have been obtained, as already observed for other concerted 1,3‐cycloadditions.
Reactions with diazoazoles. Part VI. Unequivocal synthesis of 3‐methyl‐3h‐azolotetrazoles. Correction of the formerly described 3‐methylazolotetrazoles in favour of mesoionic 2‐methylazolotetrazoles
Authors: Ege Günter , Heck Reinhard , Gilbert Karlheinz , Irngartinger Hermann , Huber‐Patz Ursula , Rodewald Hans 
Published: May 2009

Abstract3‐Methyl‐3H‐pyrazolo[1,5‐d]tetrazoles 2 and 3‐methyl‐6‐phenyl‐3H‐1,2,4‐triazolo[1,5‐d]tetrazole (4) have been unequivocally synthesized by annulation of the tetrazole moiety to the pyrazole resp. 1,2,4‐triazole system. The constitution of some N‐methyl substituted azolotetrazoles, formerly described as 3‐methyl‐3H‐pyrazolo[1,5‐d]tetrazoles 2, 3‐methyl‐6‐phenyl‐3H‐1,2,4‐triazolo[1,5‐d]tetrazole (4) and 1‐methyl‐6‐phenyl‐1H‐1,2,4‐triazolo[4,3‐d]tetrazole (5), has to be revised in favour of the corresponding mesoionic 2‐methyl derivatives 2′, 4′, 5′. The structures of 3‐methyl‐3H‐ as well as of 2‐methyl‐2H‐pyrazolo[1,5‐d]tetrazole derivatives 2a, 2c, 2′a have been determined by X‐ray analyses. The azapentalenic system is aromatic in all three measured compounds and mesoionic in the case of the 2‐methyl‐2H‐ substitution pattern. The phenyl and ester substituents are coplanar with the azapentalene system. 3‐, 2‐, and 1‐Methylpyrazolo[1,5‐d]tetrazoles exhibit different behaviour when allowed to react with stannous chloride or sodium ethoxide. Azolotetrazoles with a methyl substituent at N‐1, N‐2 or N‐3 of the tetrazole moiety can be distinguished by a combination of 1H and 13C nmr with respect to the chemical shifts of the N‐methyl group and the bridgehead carbon. Results of semiempirical calculations of the pyrazolo[1,5‐d]tetrazole anion and of its N‐methyl derivatives are discussed.
Angular heterocycles. Utilization of arylaminonaphthoquinones in the synthesis of benzophenothiazines
Authors: Agarwal Nand L. , Atal Chand K. 
Published: May 2009

AbstractSubstituted 6‐ethoxyanilino‐5H‐benzo[a]phenothiazin‐5‐ones (3a‐f) were synthesized by the cyclocondensation of 2‐chloro‐3‐ethoxyanilino‐1,4‐naphthoquinones with zinc mercaptides of 2‐aminothiophenol in pyridine. The nmr, ir and mass spectral data are presented and discussed.
Synthesis of some new pyrimido[1,6‐a]pyrimidines
Authors: Pegiadou‐Koemtjopoulou S. , Tsatsaronis G. 
Published: May 2009

Abstract4‐Amino‐5‐arylpyrimidines 1 react with diethyl alkylmalonates 2 to give pyrimido[1,6‐a]pyrimidines 4 in satisfactory yields. A possible mechanistic scheme and the spectral data of the reaction products are discussed.
Total synthesis of 4,5,7a,8‐tetrahydro‐1,2‐dimethoxyphenanthro[10,1‐bc]‐azepin‐6(7H)‐one: A photochemical approach
Authors: Jensen Bruce L. , Chockalingam Kannappan 
Published: May 2009

AbstractThe total synthesis of a novel benzazepine, 4,5,7a,8‐tetrahydro‐1,2‐dimethoxyphenanthro[10,1‐bc]azepin‐6(7H)‐one is described. Of crucial importance to the preparation of this material was a regiospecific Beckmann rearrangement reaction and the development of an aryl‐aryl linkage by a photochemically induced coupling. Details of successful and attempted methodology are reported.
Proton‐ionizable crown compounds. 4. New macrocyclic polyether ligands containing a triazole subcyclic unit
Authors: Bradshaw Jerald S. , Nielsen Ralph B. , Tse Pui‐Kwan , Arena Giuseppi , Wilson Bruce E. , Dalley N. Kent , Lamb John D. , Christensen James J. , Izatt Reed M. 
Published: May 2009

AbstractA series of macrocyclic polyether (crown) ligands containing the proton‐ionizable s‐triazole subcyclic unit were prepared by reacting the 1‐THP blocked 3,5‐bis(chloromethyl)‐1H‐1,2,4‐triazole with various oligoethylene glycols. The starting bis(chloromethyl)triazole is a vessicant and must be used with caution. Triazolo‐18‐crown‐6 (5) formed stable complexes with barium, strontium, copper and benzylammonium cations but not with potassium or lithium. The crystal structure of 5 showed the triazole proton to be on nitrogen 3 which is outside the macroring cavity.
Synthesis and spectral properties of optically active 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine: Primary methadone metabolite
Authors: Brine George A. , Boldt Karl G. , Bondeson Virginia C. , Carroll F. Ivy 
Published: May 2009

AbstractThe synthesis of the optical isomers of 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine is reported. The1H‐nmr analysis suggested that the free bases exist predominantly in an enamine form and the corresponding perchlorate salts in an iminium form. Optical studies showed that the free bases exhibit Cotton effects in the 400–230 nm region and that these Cotton effects are consistent with a fairly rigid enamine structure.
Oxidation of heterocyclic nitrogen Ylids to nitro heterocycles. Comparison of a sulfilimine and a phosphine imine
Authors: Coburn Michael D. 
Published: May 2009

AbstractOxidation of 3‐amino‐4‐(4‐chlorophenyl)furazan (1) with peroxytrifluoroacetic acid (ptfa) gave azoxy(4‐chlorophenylfurazan) (6) as the major product along with a small amount of 3‐(4‐chlorophenyl)‐4‐nitrofurazan (5). The dimethylsulfilimine 2 derived from 1 gave near quantitative yields of 5 when subjected to oxidation with either ptfa or m‐chloroperoxybenzoic acid (mcpba). In contrast, both the trioctylphosphine imine 3 and the triphenylphosphine imine 4 derived from 1 were oxidized by mcpba to give 6 as the exclusive product.
Synthesis of amino substituted 4‐oxo‐1,2,3,4‐tetrahydropyridines from arylhydrazones and methyl acrylate
Authors: Barluenga J. , Palacios F. , Viña S. , Gotor V. 
Published: May 2009

AbstractArylhydrazones react with methyl acrylate in the presence of aluminium chloride to afford amino substituted 4‐oxo‐1,2,3,4‐tetrahydropyridines.
On the amination of pteridines by liquid ammonia‐potassium permanganate
Authors: Sladowska H. , De Meester J. W. G. , Van Der Plas H. C. 
Published: May 2009

Abstract7‐Phenyl‐, 7‐(p‐methoxyphenyl)‐, 7‐methyl‐, 7‐t‐butyl‐, 6,7‐diphenyl‐, 6,7‐dimethyl‐ and 2‐phenylpteridine are converted in good yields into their respective 4‐amino compounds, when they are dissolved in liquid ammonia (‐40°) and potassium permanganate is added to the solution. Increase of the temperature of the amino‐oxidation did not change the position of substitution, the yields are however lower. The intermediary of 4‐aminodihydropteridines in these reactions has been proved by 1H nmr spectroscopy.
Synthesis of 1,8‐naphthyridine derivatives. Potential antihypertensive agents. 1
Authors: Ferrarini Pier Luigi , Mori Claudio , Primofiore Giampaolo 
Published: May 2009

AbstractReaction of substituted 7‐chloro‐1,8‐naphthyridines with N‐carbethoxypiperazine gave in good yields the corresponding 7‐(4‐carbethoxypiperazin‐1‐yl)‐1,8‐naphthyridines V as potential antihypertensive agents.
Chlorimine formation and deamination of the model nucleobase 1‐methylcytosine
Authors: Beyerle‐Pfnür Rut , Lippert Bernhard , Schöllhorn Helmut , Matischok Petra , Thewalt Ulf 
Published: May 2009

AbstractTreatment of the model nucleobase 1‐methylcytosine with chlorine in aqueous solution gives, depending on the reaction conditions, 5‐chloro‐1‐methylcytosine (3) or its hemiprotonated form 2, 5,5‐dichloro‐6‐hyd‐roxy‐5,6‐dihydro‐4‐chlorimino‐1‐methylpyrimidin‐2‐one (5), and 5,5‐dichloro‐6‐hydroxy‐5,6‐dihydro‐1‐methyl‐uracil (4). While substitution of H5 of 1‐methylcytosine by chlorine giving 2 and 3, and subsequent addition of hypochlorous acid to the 5,6‐double bond is not unexpected, chlorination of the exocyclic amino group 5 and deamination to give 4 is novel. The X‐ray structures of 4 and 5 are reported.
Etude de la décomposition thermique d'azido dithiényl‐1,2 éthènes et éthanes
Authors: Farnier Michel , Brost Michèle , Hanquet Bernard , Guilard Roger 
Published: May 2009

AbstractLa décomposition thermique des azido dithiényl‐1,2‐éthènes 1 conduit aux thiényl 4H‐thiéno[3,2‐b]pyrroles 3. Lorsque la disubstitution thiophénique porte sur les positions 3 et 4, la fonction azide des dérivés 2 est alors transformée en amine. Par contre, seuls les azido dithiényl‐1,2 éthanes 7 livrent après cyclisation les thiényl di‐hydro‐5,6 4H‐thiéno[3,4‐b]pyrroles 8. La structure des produits isolés est établie sur la base des données rmn 1H, ir et de spectrométrie de masse.
Synthèse d'azido dithiényl‐1,2 éthènes et éthanes
Authors: Farnier Michel , Brost Michèle , Hanquet Bernard , Guilard Roger 
Published: May 2009

AbstractDeux modes aisés de préparation d'azido dithiényl‐1,2 éthènes sont décrits. La synthèse d'azido dithiényl‐1,2 éthanes est réalisée via la métallation (n‐Buli) suivie de l'action du tosylazide sur des bromo dithiényl‐1,2 éthanes. Les structures des dérivés isolés sont établies sur la base des données rmn 1H, ir et de spectrométrie de masse.
Reactions of ketenes. XX. Phenylketene dimethylacetal as synthon for the introduction of functionalized phenylethyl units
Authors: Graziano M. Liliana , Iesce M. Rosaria , Scarpati Rachele 
Published: May 2009

AbstractPhenylketene dimethylacetal (1) reacts with the α‐diazoketones to give the dihydrofurans 6. These compounds, as cyclic ortho esters, can undergo dealcoholation into the furans 2 and hydrolysis into the γ‐ketoesters 3 and into the γ‐ketoacids 4. Cyclopropane acetal 8, obtained starting from acetal 1 and ethyl diazoacetate, by heating leads quantitatively to functionalized ester 9. These synthetic methods enlarge the sphere of applicability of the electron‐rich alkene 1 as synthon in organic synthesis.