bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucléosides de synthèse XXI. Obtention spécifique de ribonucléosides de configuration anomérique α
Authors: Rayner Bernard , Tapiero Claude , Imbach Jean‐Louis 
Published: March 2009

AbstractA partir de l'α‐D‐ribofuranno[1,2‐d]oxazolidine thione‐2 (2), on décrit une voie de synthése stéreospecifi‐que de l'α‐D‐ribofurannosyl‐1 carboxamido‐4 amino‐5 imidazole (1), précurseur chimique de ribonucleosides de configuration anomerique α.
Nucléosides de synthése XXII: Obtention, comme synthons oligoxylonucléotidiques, de d‐xylofurannosyl adenines spécifiquement substitués
Authors: Gosselin Gilles , Imbach Jean‐Louis 
Published: March 2009

AbstractCe travail décit la synthése de certains synthons nécessaires à l'obtention d'oligoxylonucléotides. L'utilisation d'un xyloside dissymétriquement substitué en 2 nous a permis de parvenir, avec des rendements satisfaisants, aux nucleosides desires, convenablement protéges. L'ensemble des composes décrits a été entiére‐ment caracterise par les méthodes usuelles d'analyse.
Synthesis of s‐triazines bearing three different substituents
Authors: Lin Yang‐i , Fields Thomas L. , Lee Ving J. , Lang S. A. 
Published: March 2009

AbstractReaction of N′‐acyl‐N,N‐dimethylamidines with hydrogen sulfide in acetic acid gave N‐thioacylbenzarmides in almost quantitative yields. S‐Ethylation of the N‐thioacylbenzamides with iodoethane gave N‐aroylthio‐imidates in excellent yields. Reaction of the N‐aroylthioimidates with acetamidine, benzamidine, or guanidine in ethanol gave s‐triazines in 60–93% yield.
The topology and the aromaticity of coumarins
Authors: Ilić P. , Mohar B. , Knop J. V. , Jurić A. , Trinajstić N. 
Published: March 2009

Abstract2H‐l‐benzopyran‐2‐one (coumarin), its isomers and derivatives are considered as aromatic or potentially aromatic chemical species and analyzed as such by use of standard and parameter‐varying graph‐theoretical procedures. Theoretical results are interpreted within the bounds set by existing chemical evidence.
The reaction of benzylidenetriphenylphosphoranes with benzenediazonium‐2‐carboxylate
Authors: Compagnini Anna , Vullo Adriana Lo , Chiacchio Ugo , Corsaro Antonio , Purrello Giovanni 
Published: March 2009

AbstractThe title reaction affords to the adducts 3 which upon alkaline treatment give compounds 5, while by thermolysis give 6 and 7. Hydrochloride salts of 3 in refluxing xylene afford to chlorohydrazones 10 as the major products. A mechanism is proposed for thermal decomposition of 3.
Synthesis and mass spectrometry of 4‐oxo‐4,5,6,7‐tetrahydroindole and 4‐oxo‐4,5,6,7‐tetrahydrobenzofuran derivatives
Authors: Dagher C. , Hanna R. , Terentiev P. B. , Boundel Y. G. , Kost A. N. , Maksimov B. I. 
Published: March 2009

AbstractWe describe in this communication the synthesis and mass spectrometry of some l‐aryl‐2‐phenyl‐4‐oxo‐4,5,6,7‐tetrahydroindole (IIIb, IVab‐VIIIab, VIIIb, IXb) and 2‐phenyl‐4‐oxo‐4,5,6,7‐tetrahydrobenzofuran derivatives (IIab). The fragmentations of these compounds are characterized by selectivity and the absence of any primary fragmentations involving substituents of the aryl rings. It is suggested that positive charges of the molecular ions of compounds IIIX are localized in the region of the carbonyl group and the conjugated double bond of the heterocycle.
Spectrophotometric determination of the apparent ionization exponents of 5,6‐dihydrouracil and 5,6‐dihydrothymine
Authors: Butler Thomas C. , Johnson Dorothy , Dudley Kenneth H. 
Published: March 2009

AbstractThe spectrophotometric determination of the apparent ionization exponents of 5,6‐dihydrouracil (DHU) and 5,6‐dihydrothymine (DHT) is described. The values of pK′α at 37°C and ionic strength of 0.16 are 11.42 for DHU and 11.57 for DHT.
Reactivity of 1H‐pyrrolo[2,3‐b]pyridine. I. Synthesis of 3‐acetyl‐7‐ azaindole and related compounds
Authors: Gálvez C. , Viladoms P. 
Published: March 2009

AbstractThe behaviour of 1H‐pyrrolo[2,3‐b)pyridine (7‐azaindole) towards several acylating reagents are reported. The preparation of 3‐acetyl‐7‐azaindole, 3‐chloroacetyl‐7‐azaindole and 3‐(2‐hydroxiethyl)‐7‐azaindole are described.
Electrochemical synthesis of 3,5‐diphenyl‐2(3H)‐furanone
Authors: Barba Fructuoso , Velasco M. Desamparados , Guirado Antonio 
Published: March 2009

AbstractFrom electrochemical reduction of phenacyl bromide, 3,5‐diphenyl‐2(3H)‐furanone was obtained as a side‐product and its structure was determined by chemical and spectral techniques.
Studies on pyrazines, 8. An improved syntheses of 2‐amino‐3,5‐dibromo‐ and 2‐amino‐5‐bromopyrazines
Authors: Sato Nobuhiro 
Published: March 2009

AbstractThe titled dibromopyrazine (2) was prepared in 54% yield by the modified procedure for bromination of 2‐aminopyrazine (1) using bromine and pyridine in chloroform solution. Similarly, 2‐amino‐5‐bromopyrazine (3) was directly prepared in 36% yield by bromination using 1.2 equivalents of the above reagents.
Two syntheses of 5‐chloro‐3‐(2‐thienyl)‐2,1‐benzisoxazole
Authors: Klemm L. H. , Klopfenstein C. E. , Nelson Steven K. 
Published: March 2009

Abstract5‐Chloro‐3‐(2‐thienyl)‐2,1‐benzisoxazole (2) resulted from condensation of (a) o‐nitrobenzaldehyde with thiophene in the presence of hydrochloric acid and (b) p‐chloronitrobenzene with 2‐cyanomethylthiophene. Spectral data for (2) are presented and interpreted.
Studies of the synthesis of heterocyclic compounds. Part VII. The preparation of some new 3‐ and 5‐amino‐pyrazoles by endocyclic N‐substitution of 3(5)‐aminopyrazoles
Authors: Plescia Salvatore , Daidone Giuseppe , Bajardi Maria L. 
Published: March 2009

AbstractBy reaction of some 4‐carbethoxy(or cyano)‐3(5)‐R‐5(3)‐aminopyrazoles 1 with 2‐nitrobenzoyl chloride or 2‐nitrobenzenesulfonyl chloride, a number of novel 3‐ and 5‐amino‐1‐(2‐nitrobenzoyl or 2‐nitrobenzene‐sulfonyl)pyrazoles 6 and 7 were obtained. Every compound appearing during the endocyclic N‐substitution process can be identified and determined by glc. The use of nmr offers a rapid, unambigous method for determining the proposed structures.
Sur la synthèse d'alkoxy‐2 nitro‐3 2H‐chroménes
Authors: René Loïc , Faulques Michelle , Royer Rene 
Published: March 2009

AbstractLes alkoxy‐2 nitro‐3 2H‐chromenes sont obtenus par condensation de β‐nitroacétaldéhyde dialkyl acétals et d'aldéhydes salicyliques diversement substitues, en présence de para toluéne sulfonate de triéthylamine.
Sur une synthése nouvelle et rentable du triméthyl‐3,5,5 dihydro‐4,5 isoxazole
Authors: Dauzonne Daniel , Demerseman Pierre , Royer RenÉ 
Published: March 2009

AbstractLe triméthyl‐3,5,5 dihydro‐4,5 isoxazole peut ětre prépare avec un excellent rendement en chauffant pendant 170 heures l'oxime de l'acétone dans du chlorure de pyridinium à l'ébullition.
Synthesis of anticonvulsant activity of some 2‐phenylcarbamoyl‐1,2‐diazabicyclo[2.2.2]octanes
Authors: Kornet Milton J. , Chu John Yeou‐Ruoh 
Published: March 2009

AbstractA number of aryl isocyanates were adducted to 1,2‐diazabicyclo[2.2.2]octane and afforded 2‐phenyl‐carbamoyl‐1,2‐diazabicyclo[2.2.2]octanes. Some of the products displayed anticonvulsant activity.
Deoxygenation of allylic carbinolamides and related alcohols by acidic sodium cyanoborohydride: Scope and limitations
Authors: Drage James S. , Earl Richard A. , Vollhardt K. Peter C. 
Published: March 2009

AbstractAcidic sodium cyanoborohydride reduces allylic and other substituted carbinolamides to the corresponding deoxygenated compounds, whereas other similar alcohols are unreactive or undergo alternative transformations.
A novel synthesis of 7‐acetyl‐4,5,5a,6,6a,7,8,9‐octahydroindeno[7,1‐fg]quinolin‐9‐one
Authors: Bowman Ralph E. 
Published: March 2009

AbstractTreatment of the acetylenic acid 3 with magnesium carbonate in water at 60° yielded the tetracyclic ketone 5.
Oxidation of arylacetylhydrazones of carbonyl compounds with lead tetraacetate
Authors: Stephanidou‐Stephanatou J. , Lefkopoulou S. 
Published: March 2009

AbstractOxidation of the title compounds 8, 9 with lead tetraacetate at room temperature gives a variety of products depending on the substituents on the carbonyl carbon atom. Thus, on oxidation of the aldehyde derivatives 8 1,3,4‐oxadiazolo derivatives 10 are obtained in good yields. However in some cases formation of N‐acetyl‐N‐arylacetyl‐N′‐benzoylhydrazines 11 is also observed, whereas oxidation of the ketone hydrazones 9 gives in good yields the 2H,5H‐1,3,4‐oxadiazoles 15 or substituted monoacetoxy‐ 17 and diacetoxyalkanes 18. The reaction mechanisms are also discussed.
Synthesis and reactions of 2H‐Benzothieno[3,2‐d][1,3]oxazine‐2,4(1H)‐dione
Authors: Coppola Gary M. , Hardtmann Goetz E. , Pfister Oskar R. 
Published: March 2009

AbstractThe title compound 5 is synthesized by the reaction of the potassium salt of 3‐aminobenzo[b]thiophene‐2‐carboxylic acid with phosgene. Compound 5 is readily alkylated to give 6 with methyl iodide, benzyl bromide, or propargyl bromide in the presence of sodium hydride. Reaction of 5 and 6 with nucleophiles follows specifically different pathways. Compound 5 is readily ionized to the isocycanate species 13 and subsequently reacts with methanol or methylamine to produce exclusively the carbamate 7 or ureido acid 9. The N‐substituted derivative 6, in analogous reactions with methanol or methylamine, produce exclusively the amino ester 8 or the amino amide 10. The N‐benzyl derivative 6b reacts with the cyclic S‐methylthiopseudourea 11 to give the tetracycle 12, a new ring system.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (isatoic anhydride). 9. Synthesis of 2‐arylquinoline alkaloids
Authors: Coppola Gary M. 
Published: March 2009

AbstractA one‐step synthesis of N‐methyl‐2‐aryl‐4‐quinolone alkaloids is described. These compounds are readily prepared from the reaction of an N‐methylisatoic anhydride with the lithium enolate of an acetophenone. By this method, the reaction of N‐methylisatoic anhydride (5) or 5‐methoxy‐N‐methylisatoic anhydride (7) with acetophenone produces the alkaloids N‐methyl‐2‐phenyl‐4‐quinolone (1) and eduline (2) in 81% and 70% yield, respectively. An analogous reaction of 5 with 3,4‐methylenedioxyacetophenone gives graveoline (3) in 63% yield whereas 7 and α‐methoxyacetophenone affords japonine (4) in 61% yield.
Synthesis of substituted thiacrown ethersviaa bromoalkoxylation reaction
Authors: Nakatsuji Yohji , Mizuno Tadashi , Okahara Mitsuo 
Published: March 2009

AbstractA variety of alkyl‐ or phenyl‐substituted thia‐crown ethers were prepared in two or three stepsviabromoalkoxylation reactions of olefins. Dialkyl‐ and phenyl‐substituted mono‐and dithia‐crown ethers were obtained as single compounds, whereas monoalkyl‐substituted derivatives were a mixture of two positional isomers reflecting the isomeric mixture formation in the bromoalkoxylation reaction.
Pyridiniums as potential synthetic substitutes for nitrogen mustards
Authors: Katritzky Alan R. , Burgess Kevin , Patel Ranjan C. 
Published: March 2009

AbstractDialkylamino‐alkyl primary amines 1b and 2b are converted by pyrylium salts into the corresponding pyridinium derivatives. The pyridinium salts act as aminoalkylating agents for representative O‐, S‐, N‐, and C‐nucleophiles and are potentially safe substitutes for nitrogen mustards in the reactions.
Antibakterielle wirkstoffe. VIII . Die aminomethinylierung in der reihe der aminothiazole
Authors: Kreutzberger Alfred , Kreutzberger Elfriede , Saltler Hans‐Joachim , Amâl Hayriye , Gürsoy Aysel 
Published: March 2009

AbstractAus der die Umsetzung von 2‐Amino‐4‐antipyrinyl‐5‐ethylthiazol (1) mit s‐Triazin (2) und Pyrrolidin beinhaltenden Dreikomponentenreaktion geht das 4‐Antipyrinyl‐5‐ethyl‐2‐[(4‐pyrrolidinyl)methylenamino]thiazol (5) hervor. Struktur 5 läßt sich durch 1H‐ und 13C‐NMR‐Spektroskopie untermauern.
Construction of pyrimido[5,4‐e]‐as‐triazine, purine, v‐triazolo‐[4,5‐d]pyrimidine and pyrazolo[3,4‐d]pyrimidine ring systems from 5‐arylazo‐6‐arylidenehydrazino‐1,3‐dimethyluracils
Authors: Nishigaki Sadao , Ichiba Misuzu , Fukami Kiyoko , Senga Keitaro 
Published: March 2009

AbstractReaction of 5‐arylazo‐6‐arylidenehydrazino‐1,3‐dimethyluracils (II), prepared by the treatment of 6‐aryl‐idenehydrazino‐1,3‐dimethyluracils (I) with diazotized arylamines, with dimethylformamide dimethylacetal resulted in the formation of pyrimido[5,4‐e]‐as‐triazine (V) system, while the thermolysis of II resulted in the formation of purine (X), v‐triazolo[4,5‐d]pyrimidine (XII), and pyrazolo[3,4‐d]pyrimidine (XIV, XIX) systems in lieu of the expected V. Reasonable mechanisms have been proposed for the formation of the various ring systems in these reactions.
Convenient syntheses of 3,6‐dialkyl‐1,4‐dihydroxy‐2,5‐dioxopiperazines
Authors: Ohta Akihiro , Yamamoto Fusako , Arimura Yasuhiko , Watanabe Tokuhiro 
Published: March 2009

AbstractSome 3,6‐dialkyl‐1,4‐dihydroxy‐2,5‐dioxopiperazines were conveniently prepared from the corresponding 3,6‐dialkyl‐2,5‐dichloropyrazines via their 1,4‐dioxides and 3,6‐dialkyl‐2,5‐dihydroxypyrazine 1,4‐dioxides. On the basis of the examination of pmr, tlc, and glc of the 2,5‐dioxopiperazines derived from the products, it was clarified that all the products were cis‐diastereomers.
Synthesis of some heterocyclic systems from nucleophilic substitution reactions with η6‐o‐dichlorobenzene‐η5‐cyclopentadienyliron hexafluorophosphate
Authors: Sutherland Ronald G. , Piórko Adam , Gill Udai S. , Lee Choi Chuck 
Published: March 2009

AbstractA method for the synthesis of heterocylic systems related to 9,10‐dihydroanthracene with two hetero‐atoms at the 9,10‐positions is described. It involves the nucleophilic substitution reaction of η6‐o‐dichlorobenzene‐η5‐cyclopentadienyliron hexafluorophosphate with two nucleophilic groups (OH, SH and/or NH2) located in the 1,2‐positions of a benzene ring to give a cyclopentadienyliron complexed heterocycle. Upon pyrolytic sublimation of the complex, the free heterocyclic compound is then obtained.
New syntheses of pyrido[3,2‐d]pyrimidines
Authors: Senga Keitaro , Fukami Kiyoko , Kanazawa Hashime , Nishigaki Sadao 
Published: March 2009

AbstractNew synthetic routes to pyrido[3,2‐d]pyrimidines starting with 5‐amino‐1,3,6‐trimethyluracil (I) or 1,3,6‐trimethyl‐5‐nitrouracil (X) are described. Thus, condensation of I with arylaldehydes gave 5‐arylideneamino‐1,3,6‐trimethyluracils (IIa‐h), which upon heating with dimethylformamide dimethylacetal afforded 6‐aryl‐1,3‐dimethylpyrido[3,2‐d]pyrimidine‐2,4(1H,3H)‐diones (Va‐h) via 5‐arylideneamino‐1,3‐dimethyl‐6‐(2‐dimethylaminovinyl)uracils (IIIa‐h). On the other hand, reaction of X with phenylacetaldehyde in the presence of base yielded Va and its 5‐oxide (XI).
Aminopyrazoles. Part 3. Synthesis of the novel ring systems pyrazolo[4′,3′:5,6]pyrido[2,3‐b][1,5]benzoxazepine and [1,5]benzothiazepine
Authors: Simay Antal , Takács Kálmán 
Published: March 2009

AbstractTwo‐step synthesis of the novel fused heterocycles pyrazolo[4′,3′:5,6]pyrido[2,3‐b][1,5]benzoxazepine (8) and pyrazolo[4′,3′:5,6]pyrido[2,3‐b][1,5]benzothiazepine (9) from the pyrazolo[3,4‐b]pyridine derivative 1 is described.
Pyrazolo[1,5‐d]triazines‐1,2,4. II étude des pyrazolo[1,5‐d]triazinones, des pyrazolo[1,5‐d]triazinediones et des pyrazolo[1,5‐d]triazinethiones
Authors: Lancelot Jean Charles , Maume Daniel , Robba Max 
Published: March 2009

AbstractLa synthèse de la dihydro‐1,2 oxo‐1 pyrazolo[1,5‐d]triazine‐1,2,4 1 est effectuée par transposition en milieu alcalin du (pyrazolyl‐5)‐2 oxadiazole 3 alors que la dihydro‐3,4 oxo‐4 pyrazolo[1,5‐d]triazine‐1,2,4 5 est accessible par cyclisation en milieu alcalin de la N‐carbéthoxyhydrazone du formyl‐5 pyrazole 6. Les réactions de substitution de la pyrazolotriazinone 1 sont réalisables soit au niveau de l'azote lactamique avec des agents électrophiles soit au niveau du cycle pyrazolique en 8. La pyrazolotriazinone 1 permet d'accéder à la pyrazolo[1,5‐d]triazine‐1,2,4 20 par l'intermédiaire de la pyrazolotriazinethione 10 qui est désulfurée par le Nickel de Raney. La méthylation des pyrazolotriazinethiones 10 et 11 conduit à des N‐ ou à des S‐substitutions selon les conditions. Les pyrazolotriazinediones 21 et 22 sont obtenues par cyclisation de N‐carbéthoxyhydrazides pyrazoliques. Les spectres de rmn confirment la structure des dérivés obtenus.
5‐Substituted‐3‐(substituted)phenyl‐1,3,4‐oxadiazolin‐2(3H)‐ones. Synthesis and reactions with nucleophilic reagents
Authors: Pilgram Kurt H. 
Published: March 2009

AbstractA new synthesis of 4,4‐dialkyl‐2‐(substituted)phenylsemicarbazides has been developed. The procedure begins with a 5‐substituted‐3‐(substituted)phenyl‐1,3,4‐oxadiazolin‐2(3H)‐one, 3, which is treated with dialkylamine to give a 1‐acyl‐4,4‐dialkyl‐2‐(substituted)phenylsemicarbazide, 7. Subsequent base‐catalyzed hydrolysis of 7 gives 4,4‐dialkyl‐2‐(substituted)phenylsemicarbazides, 14, in high yield. With a variety of nucleophilic reagents, the compounds 3 also undergo ring opening.
The structure of thianthrenium biscarbethoxymethylide and the corresponding sulfoxide
Authors: Ternay A. L. , Baack J. C. , Chu S. S. C. , Napoleone V. , Martin G. , Alfaro C. 
Published: March 2009

AbstractThianthrene reacts with one equivalent of diethyl diazomalonate to form the monosulfonium ylide thianthrenium biscarbethoxymethylide. Single crystal X‐ray and 13C‐nmr establish the conformation as pseudoequatorial (e') in both the solid state and solution. The angle of fold between aryl rings is 135.7°, the nearlyplanar malonylide fragment bisecting this angle. The carbonyl oxygen of the endo carbethoxy group is anti to the nonbonding electron pair on sulfur. The methylide carbon resonates at 50 ppm. The aromatic solvent induced shift (ASIS) technique indicates that thianthrene Soxide also is e'.
Synthesis and reactions of some dihydro and tetrahydro‐4H‐imidazo[5,4,1‐ij]quinoline derivatives
Authors: Saari Walfred S. , Halczenko Wasyl , Freedman Mark B. , Arison Byron H. 
Published: March 2009

AbstractReaction of phenyl N‐(8‐quinolinyl)carbamate with sodium borohydride afforded 1,2‐dihydro‐4H‐imidazo‐[5,4,1‐ij]quinolin‐2‐one, 2a. The 5,6‐double bond of 2a was functionalized by reaction with nitrosyl chloride to give the nitroolefin 4 and by reaction with hypobromous acid to give the trans‐bromohydrin 5. Reaction of 5 with sodium azide led to the rearranged trans‐6‐azido‐5‐ol 7, the structure of which was determined by 1H nmr studies.
Psilocin analogs. III. Synthesis of 5‐methoxy‐ and 5‐hydroxy‐1,2,3,4‐tetrahydro‐9H‐pyrido[3,4‐b]indoles
Authors: Repke David B. , Ferguson Wilfred J. 
Published: March 2009

AbstractA number of tetrahydro‐β‐carbolines were prepared with oxygen substituents at C‐5. This class of compounds represents a hybrid between two naturally occurring groups of hallucinogenic molecules, the 4‐hydroxytryptamines and the 6‐ and 7‐oxygenated β‐carbolines.
The synthesis of the monomethyl isomers of benzo[b]naphth[2,1‐d]thiophene
Authors: Tominaga Yoshinori , Pratap Ram , Castle Raymond N. , Lee Milton L. 
Published: March 2009

AbstractAll isomers of the monomethylbenzo[b]naphth[2,1‐d]thiophenes were synthesized using photocyclization of 3‐styrylbenzo[b]thiophenes.The 1‐, 3‐, 4‐, and 5‐methylbenzo[b]naphtho[2,1‐d]thiophenes were synthesized by irradiation of the corresponding methylated 3‐styrylbenzo[b]thiophenes which were prepared by the Wadsworth‐Emmons reaction of diethyl benzo[b]thenylphosphonate with o‐, m‐, p‐tolualdehyde and acetophenone. The 7‐, 8‐, 9‐ and 10‐methylbenzo[b]naphtho[2,1‐d]thiophenes were synthesized by decarboxylation of 7‐, 8‐, 9‐ and 10‐methylbenzo[b]naphtho[2,1‐d]thiophene‐6‐carboxylic acid with copper in quinoline. These carboxylic acids were prepared by photocyclization of the corresponding 2‐(benzo[b]thiophen‐3‐yl)‐3‐phenylpropenoic acids which were prepared by the condensation of the methylated benzo[b]thiophene‐3‐ylacetic acids with benzaldehyde in the presence of triethylamine in acetic anhydride.
The synthesis of all of the monomethyl isomers of benzo[b]naphtho[1,2‐d]thiophene
Authors: Tominaga Yoshinori , Pratap Ram , Castle Raymond N. , Lee Milton L. 
Published: March 2009

AbstractAll isomers of the monomethylbenzo[bnaphtho[1,2‐d]thiophenes were synthesized by photocyclization of 2‐styrylbenzo[b]thiophenes which were prepared by the Wadsworth‐Emmons reaction or the Wittig reaction.
Acylaminoacetyl derivatives of active methylene compounds. 1. The cyclization of the benzoylaminoacetyl derivatives to α‐substituted tetramic acids
Authors: Igglessi‐Markopoulou Olga , Sandris Constantine 
Published: March 2009

AbstractHippuric acid was converted to α‐Y‐substituted tetramic acids (Y = ‐CN, ‐CO2R and ‐COCH3) according to the following general scheme of reactions: a) preparation of the hippuric acid chloride or of its p‐nitrophenyl ester; b) C‐acylation of an active methylene compound Y‐CH2‐CO2R using the acid chloride or the active ester; and c) intramolecular condensation of the C‐acylation compound to an α‐Y‐substituted tetramic acid. The conditions of the C‐acylation reaction and the structure and reactivity of the benzoylaminoacetyl derivatives were investigated.
Base‐promoted cyclization of 1‐nitrohydrazones bearing a thioether function
Authors: Bruché Luca , Garanti Luisa , Zecchi Gaetano 
Published: March 2009

AbstractFunctionalized 1‐nitrohydrazones 5 react with sodium hydride in boiling benzene to afford different types of ring‐closed products. The formation of the latter can be ascribed to competitive modes of evolution of first‐formed nitrile imines.
Nitrogen bridgehead compounds. Part 19. Synthesis of polymethylenepyrimidin‐4‐ones
Authors: Kökösi József , Szász György , Hermecz István , Mészáros Zoltán , Csákvári‐Pongor Marianne , Tóth Gábor 
Published: March 2009

AbstractReaction of five‐, six‐, seven‐, and eight‐membered cyclic amidines (1 n = 0‐3) with diethyl ethoxy‐methylenemalonate (2) yields isomeric 2,3‐polymethylene‐4(3H]‐ and 1,2‐polymethytlene‐4(1H)‐pyrimidinones (3 and 4) respectively, n = 0‐3). With 2‐aminopyrroline the isomer ratio was dependent upon the reaction conditions. The structure of the isomers 3 and 4 was studied by uv, ir and 1H‐nmr spectroscopy. Both isomers contain an active methylene group which can be deuterated. Deuteration was investigated with 1H‐nmr spectroscopy.
Synthesis of some substituted guanidinopyrimidines and their structural assignment by 13C and 1H NMR
Authors: Ladd David L. 
Published: March 2009

AbstractA series of substituted 2‐ and 4‐guanidinopyrimidines were prepared by reaction of halopyrimidines with guanidine; alkylamino and amino substituents were introduced by subsequent halogen replacement by primary amines or ammonia or the catalytic reduction of nitro groups. Structural assignments were made on the basis of 13C and 1H nmr. A guanidinopteridine and a bispyrimidinylguanidine were also synthesized. Some unsuccessful reactions illustrated the low nucleophilic reactivity and thermal instability of the guanidine group.
The reaction of o‐phenylenediamine with 3‐methylglutaric anhydride
Authors: Lombardino Joseph G. , Ewing Frank E. 
Published: March 2009

AbstractThe combination of o‐phenylenediamine and 3‐methylglutaric anhydride in xylene as solvent produces a complex mixture of products. Isolation and characterization of four products from this reaction has shed some light on the mechanism by which 4‐(2‐benzimidazolyl)‐3‐methylbutyric acid (1) is formed under these reaction conditions.
A synthesis of lumazine derivatives
Authors: Yoneda Fumio , Koga Ryosuke , Nishigaki Sadao , Fukazawa Shinobu 
Published: March 2009

AbstractTreatment of 6‐amino‐1,3‐dimethyl‐5‐nitrosouracil (Ia) with dimethyl acetylenedicarboxylate (DMAD) in dimethylformamide (DMF) afforded 6,7‐bis(dimethoxycarbonyl)‐1,3‐dimethyllumazine (II). Similarly, the reaction of 6‐amino‐1,3‐dimethyl‐5‐phenylazouracil with DMAD gave also II. Hydrolysis of II with hydrochloric acid gave 1,3‐dimethyllumazine‐6‐carboxylic acid (III). III was chlorinated with thionyl chloride and then aminated with ethanolic ammonia to give rise to 6‐carbamoyl‐1,3‐dimethyllumazine (V). V was alternatively synthesized by the treatment of Ia with propiolamide in DMF.