bluuebunny/crossref_metadata_2025 huggingface dataset:
A carbon 13‐NMR assignment study of a series of oxetanes derived from carbonyl compounds and furan and thiophene derivatives
Authors: Bolívar R. A. , Doppert K. , Rivas C.
Published: March 2009

The assignment of the carbon‐13 nmr resonances of a series of oxetanes derived from the photoaddition of benzophenone and 2‐naphthaldehyde to furan and some of its methyl derivatives and of benzophenone to 2,5‐dimethylthiophene has been made. The assignments were made by chemical shift arguments, by the use of C‐13 labelling when required and different decoupling techniques. This information may be useful in the identification of new compounds with analogous carbon skeleton.
Action de réactifs nucléophiles sur les phényl‐5 thiéno[3,2‐b]pyrannone‐7 et phényl‐2 benzo[b]thiéno[3,2‐b]pyrannone‐4
Authors: Netchitaílo Pierre , Decroix Bernard , Morel Jean
Published: March 2009

Nous étudions la réactivité de la phényl‐5 thiéno[3,2‐b]pyrannone‐7 et de la phényl‐2 benzo[b]thiéno‐[3,2‐b]pyrannone‐4 vis à vis de reactifs nucleophiles et la comparons à celle des benzopyrannones.
Reactions between 4‐hydroxy‐6‐methyl‐2‐pyrone and aldehydes both in the absence and the presence of added thiols
Authors: de March P. , Moreno‐Mañas M. , Pi R. , Trius A.
Published: March 2009

Aldehydes react with 4‐hydroxy‐6‐methyl‐2‐pyrone, 2, under Knoevenagel conditions to afford very elec‐trophilic intermediates, which can be trapped by more 2 or thiols to give dilactones 3 or monolactones 4.
Synthése de la benzopyranno[1][2,3‐b]quinoxalinone‐12
Authors: Vinot Nicole , Maitte Pierre
Published: March 2009

Les benzyl‐3 quinoxalinones‐2 sont obtenues par condensation de l'o‐phénylénediamine avec les acides phénylpyruviques. Ces quinoxalinones subissent facilement des substitutions en ‐2, qui permettent de préparer un certain nombre de dérives, mais les essais de cyclisation de ces composes en 12H‐benzopyranno‐[1][2,3‐b]quinoxaline ont échoue. Une suite de reactions classiques effectuees a partir du phenoxy‐2 quin‐oxaline carboxylate‐3 d'éthyle permet cependant d'atteindre cet héterocycle nouveau.
Fused‐s‐triazino heterocycles IX. 1,3,4,6,9b‐pentaazaphenalenes and 1,3,6,9b‐tetraazaphenalenes: Amino and alkoxy derivatives
Authors: Shaw John T. , Coffindaffer Timothy W. , Stimmel Julie B. , Lindley Patricia M.
Published: March 2009

The trichloromethyl group served as a useful leaving group in nucleophilic displacement reactions by a variety of substituted amines and alcohols (the latter under base catalysis) on 2‐trichloromethyl‐5‐methyl‐1,3,4,6,9b‐pentaazaphenalene (1a) and 2‐trichloromethyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (2a). The reaction conditions were mild and the yields of the corresponding 2‐substituted amino and alkoxy derivatives were generally good.
Studies on quinones. VIII. The application of michael adducts from 2‐hydroxy‐1,4‐naphthoquinones for the preparation of dihydronaphthopyrandiones
Authors: Cassis R. , Tapia R. , Valderrama J.
Published: March 2009

Dihydronaphthopyran‐5,10‐diones 7,13, 16 and their corresponding dihydronaphthopyran‐5,6‐diones 8, 14,17 have been obtained starting from Michael adducts of 2‐hydroxy‐ and 2‐hydroxy‐7‐methoxy‐1,4‐naph‐thoquinone (1, 9). An efficient synthesis of hydroxyhydrolapachol (4) employing 2‐hydroxy‐3‐(3‐oxobutyl)‐1,4‐naphthoquinone (5) is described.
Acylations of 1,10‐dilithiophenothiazine. A new synthesis of 1‐formylphenothiazine
Authors: Hallberg Anders , Martin Arnold
Published: March 2009

The synthesis of 1‐formyl‐, 1‐benzyyl‐, 1‐anisoyl‐, and 1‐nicotinyl‐phenothiazines (1–4) resulting from the reaction of the corresponding amids with 1,10‐dilithiophenothiazine (5) is reported. The site of attachment on 1,10‐dilithiophenothiazine, based on the nature of some different acylating reagents, is also discussed.
Synthèse d'amino‐3 thiophènes a partir d'aryl‐et d'hétaryl‐acétonitrile
Authors: Kirsch G. , Cagniant Mme D. , Cagniant P.
Published: March 2009

Par application de la synthèse de Fiesselmann, les auteurs décrivent la préparation d'amino‐3 thiophènes substitués par des groupements aryles ou hétaryles.
The stereochemistry of organosulfur compounds. XIX. The crystal and molecular structure of 10‐(1,3‐dithiolan‐2‐ylidene)‐10H‐indeno[1,2‐f]‐1,2,3,4,5‐pentathiepin
Authors: Korp James D. , Bernal Ivan , Watkins Steven F. , Fronczek F. R.
Published: March 2009

The molecular structure of 10‐(1,3‐Dithiolan‐2‐ylidene)‐10H‐indeno[1,2‐f] ‐1,2,3,4,5‐pentathiepin S7C12H89 has been determined by single crystal X‐ray diffraction. The crystals are triclinic, space group PI, with two molecules in a unit cell of dimensions α = 8.931(2), b = 9.387(2), c = 10.175(2) Å, α = 75.73(2), β = 73.35(1), γ = 64.37(2)°. The structure was solved by direct methods, and refined to a final R value of 3.3% for 1925 independent reflections. The molecule consists of an indene core with a nearly co‐planar dithiolane and a fused pentasulfide chain. The S5C2 ring is in the chair configuration, with an average SS distance of 2.052 Å. There is no variation of bond lengths as is frequently seen in multi‐sulfur chains. The indenone ring shows no evidence of any delocalization, while the dithiolane ring is disordered at the two methylene positions. No attempt was made to resolve the disorder, since it is frequently seen and has been thoroughly investigated previously.
Studies on uracil derivatives and analogs. Syntheses of 5‐(βt‐trimethylsilyl)ethynyluracil and 5‐ethynyluracil
Authors: Kundu Nitya G. , Schmitz Scott A.
Published: March 2009

5‐(α‐Chlorovinyl)‐2,4‐dichloropyrimidine (I) on treatment with sodium methoxide in methanol was converted to 2,4‐dimethoxy‐5‐ethynylpyrimidine (II) which was silylated by t‐butyl lithium and chlorotrimethylsilane to 2,4‐dimethoxy‐5‐β‐trimethylsilyl)ethynylpyrimidine (IV). Compound IV on deblocking with trimethylsilyl iodide yielded 5‐(β‐trimethylsilyl)ethynyluracil (V), which on treatment with sodium hydroxide in methanol was converted to 5‐ethynyluracil (VI).
Syntheses and reactions of some 2,3‐disubstituted pyrazine monoxides
Authors: Ohta Akihiro , Masano Sawako , Iwakura Sachiko , Tamura Akiko , Watahiki Hiroko , Tsutsui Mayumi , Akita Yasuo , Watanabe Tokuhiro , Kurihara Teruo
Published: March 2009

The reactions of 2,3‐dimethyl‐ (4), 2,3‐diphenyl‐ (6), and 2‐methyl‐3‐phenyl‐pyrazine monoxides (8 and 9) with phosphoryl chloride and acetic anhydride resulted in giving monochloro‐ and monacetoxy‐pyrazines in almost all cases. However, the reaction of 6 with acetic anhydride afforded exceptionally a diacetoxydihydro‐pyrazine. These products were converted further to hydroxy or dichloro derivatives.
Structures de deux β‐énaminoesters cycliques: l'α‐(tétrahydropyrrolidinylidéne‐2) acétate d'éthyle et l'α‐(hexahydroazepinylidéne‐2) acétate d'éthyle
Authors: Philoche‐Levisalles Michèle , Bois Claudette , Célérier Jean‐Pierre , Lhommet Gérard
Published: March 2009

La détermination des structures des α‐(tétrahydropyrrolidinylidène‐2) et α‐(hexahydroazepinylidéne‐2) acétates d'éthyle a été effectuée par diffraction des RX sur monocristaux. II est ainsi montré qu'á l'etat solide ces composés sont sous forme β‐énaminoesters de configuration Z et qu'il existe des liaisons intra et intermoleculaires.
Isomeric tropane analogues of histamine H2‐receptor antagonists
Authors: Bagley Jerome R. , Riley Thomas N.
Published: March 2009

In an attempt to investigate stereochemical requirements of antagonists of the histamine H2‐receptor, tropane analogues of cimetidine and metiamide have been synthesized possessing axial and equatorial N‐methylthiourea and N‐methyl‐N‐cyanoguanidine moieties at the 3‐position of the tropane system. The tropane analogues of this study have been fully characterized with regard to configuration at C‐3 and to conformation of the piperidine ring of the tropane nucleus.
Hydroxide‐catalyzed synthesis of heterocyclic aromatic amine derivatives from nitriles
Authors: Smyrl Norman R. , Smithwick Robert W.
Published: March 2009

A generalized method for synthesizing a wide variety of heterocyclic aromatic amine derivatives from nitriles by use of hydroxide catalysts is presented. Nitrile dimers (3‐aminocrotononitrile and dicyandiamide) and a dimer analog (anthranilonitrile) react with monomeric nitriles in the presence of hydroxide to form respectively, aminopyrimidines, diaminotriazines and aminoquinazolines.
Studies on the chemical synthesis of potential antimetabolites. 30. Regioselective introduction of a chlorine atom into the imidazo[4,5‐b]pyridine nucleus
Authors: Itoh Tokuo , Ono Kazuo , Sugawara Tomokazu , Mizuno Yoshihisa
Published: March 2009

Reactions of some imidazo[4,5‐b]pyridine 4‐oxides with phosphoryl chloride are described. Treatment of N‐1‐substituted imidazo[4,5‐b]pyridine 4‐oxides with phosphoryl chloride led to the predominant formation of 7‐chloro derivatives. This feature was successfully applied to the preparation of a chloroimidazo[4,5‐b]pyridine nucleoside, which served as an important precursor of 1‐deazaadenosine.
Synthesis of 1,4‐benzodiazepino[4,5‐d][1,4]benzoxazepines
Authors: Effland Richard C. , Helsley Grover C. , Tegeler John J.
Published: March 2009

The novel 1,4‐benzodiazepino[4,5‐d][1,4]benzoxazepine ring system has been constructed via preformed benzoxazepine intermediates. Several derivatives have been prepared as potential anxiolytic agents.
Synthesis of substituted N‐(2,4‐dioxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides and N‐(2‐thiono‐4‐oxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides
Authors: Chau Nguyen , Saegusa Yasuo , Iwakura Yoshio
Published: March 2009

Substituted N‐(2,4‐Dioxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides (3a‐g) and substituted N‐(2‐Thiono‐4‐oxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides (4a‐g) were synthesized in one step from the reaction of methyl anthranilate with 2‐aryl‐1,3,4‐oxadiazolin‐5‐ones (1a‐g) and 2‐aryl‐1,3,4‐oxadiazoline‐5‐thiones (2a‐g), respectively, in m‐cresol at 150–160°. Alternative routes leading to the formation of 3a and 4a are also reported.
Mesoionic purinone analogs. VIII. Synthesis and properties of mesoionic 5‐substituted‐6‐methylimidazo[1,2‐c]pyrimidine‐2,7‐diones
Authors: Coburn Robert A. , Taylor Michael D.
Published: March 2009

Mesoionic imidazo[1,2‐c]‐pyrimidine‐2,7‐diones 1a‐c, analogs of purine‐2,8‐dione, were prepared from 4‐amino‐l‐methylpyrimidin‐6‐ones 6a‐c. These mesoionic purinone analogs were found to exist predominantly in the C3‐H tautomeric form 1 and to undergo hydrolytic ring‐opening reactions to produce 2‐(4‐imidazol‐idon‐2‐ylidenyl)acetamides. Reaction of 1c with dimethyl acetylene dicarboxylate produced triazacyclopent‐[cd]indene 25 via 1,3‐dipolar cycloaddition.
Cycloaddition reactions of N‐p‐toluenesulfonylimino derivatives of quinoline and isoquinoline. A route to pyrazolo[1,5‐a]quinolines and pyrazolo[5,1‐a]isoquinolines
Authors: Sundberg Richard J. , Ellis James E.
Published: March 2009

N‐p‐Toluenesulfonylimino ylides of quinoline and isoquinoline give cycloadducts with electrophilic acetylenes at 105°. The adducts are spontaneously aromatized under the conditions of their formation by elimination of p‐toluenesulfmic acid to give pyrazolo[1,5‐a]quinolines and pyrazolo[5,1‐a]isoquinolines, respectively. The orientation of cycloaddition is the same as for N‐amino ylides for acetylenic esters. The ad‐ducts from p‐nitrophenylacetylene are formed by addition of the imino nitrogen to the unsubstituted acetylenic carbon. The orientation and unreactivity of phenylacetylene indicate that the cycloaddition is controlled by dipole HOMO‐dipolarophile LUMO interactions.
Reactions of N‐heteroarylformamide oximes and N‐heteroarylacetamide oximes with N,N‐dimethylformamide dimethyl acetal. Synthesis of 2‐methyl‐s‐triazolo[1,5‐x]azines and N‐methylcyanoaminoazines
Authors: Stanovnik Branko , Štimac Anton , Tišler Miha , Verček Bojan
Published: March 2009

N‐Heteroarylformamide oximes 3 (R  H) were converted with N,N‐dimethylformamide dimethyl acetal (DMFDMA) into N‐heteroaryl‐N‐methylcyanoamino compounds 5, as the main products. In some instances N‐heteroarylcyanoamino compounds 4, cyanoimino compounds 7, and some other products, such as 9 and 10 were also formed. On the other hand, N‐heteroarylacetamide oximes 3 (R  CH3) were cyclized under the same reaction conditions into 2‐methyl‐s‐triazolo[1,5‐x]azines (6). N‐Heteroarylacetamide O‐methyl oximes 11 and 12 were prepared from the corresponding acetamidines 2 (R  CH3) and O‐methylhydroxylamine.
Nucléosides de synthèse XXI. Obtention spécifique de ribonucléosides de configuration anomérique α
Authors: Rayner Bernard , Tapiero Claude , Imbach Jean‐Louis
Published: March 2009

A 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

Ce 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

Reaction 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

2H‐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

The 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

We 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

The 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

The 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

From 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

The 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

5‐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

By 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

Les 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

Le 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

A 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

Acidic 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

Treatment 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

Oxidation 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

The 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

A 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

A 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

Dialkylamino‐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

Aus 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

Reaction 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

Some 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

A 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

New 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

Two‐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

La 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

A 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

Thianthrene 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

Reaction 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

A 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

All 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 the monomethyl derivatives of benzo[b]naphtho[2,3‐d]thiophene
Authors: Pratap Ram , Tominaga Yoshinori , Castle Raymond N. , Lee Milton L.
Published: March 2009

The synthesis of all the monomethyl derivatives of benzo[b]naphtho[2,3‐d]thiophene is described.
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

All 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

Hippuric 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

Functionalized 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

Reaction 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

A 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

The 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

Treatment 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.
Spectral studies of some substituted arylthiobenzo[f]quinolines
Authors: Bahuguna R. P. , Joshi Y. C. , Dobhal M. P. , Pande R. K. , Joshi B. C.
Published: March 2009

Synthesis and spectral studies (ir, 1H nmr, ms) of 1‐ and 3‐substituted arylthiobenzo[f]quinolines (IIIa‐IIIc, IVa‐IVc) obtained through nucleophilic displacement of the corresponding halobenzo[f]quinoline by various thiols (a‐c) were done.
Reactions of 3‐acetyltropolone and its methyl ethers with aminoguanidine
Authors: Jin Zhong‐Tian , Imafuku Kimiaki
Published: March 2009

3‐Acetyltropolone (1) reacted with aminoguanidine to afford its guanylhydrazone (3). The reaction of 3‐acetyl‐2‐methoxytropone (2a) gave 4‐methyl‐1(2H)‐phthalazinone (5), while the reaction of 7‐acetyl‐2‐methoxytropone (2b) gave its guanylhydrazone (6) and 3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐one (4). The guanylhydrazones (3 and 6) were easily cyclized to 4 by heating in acetic acid.
Synthesis and evaluation of AChE inhibitory activity of 5,6‐diaryl‐1,2,4‐triazinyloxyacetyl‐4‐substituted thiosemicarbazides, triazoles and N‐benzylidene derivatives
Authors: Sen Gupta Anil K. , Hajela Kanchan , Bhattacharya Tapas , Ahmad Shakeel , Shanker Kripa
Published: March 2009

A series of 1,2,4‐triazinyl thiosemicarbazides, triazoles and N‐benzylidene derivatives have been synthesized by condensation of 5,6‐diphenyl‐1,2,4‐triazin‐3‐yloxyacetyl hydrazine with aromatic aldehydes and aryl isothiocyanates. Subsequent ring closure of thiosemicarbazides yielded the triazoles. All the compounds were subjected to in vitro testing of cholinesterase inhibitory action. Percentage inhibition was found to be moderate to good in a few of the compounds.
Interpretation of the 13C NMR spectrum of physostigmine
Authors: Nieminen Antti O. K. , Haataja Helena , Rautio Marjatta , Rahkamaa Erkki
Published: March 2009

The 25.1 MHz 13C nmr spectrum of physostigmine in deuteriochloroform has been reanalysed with the aid of high resolution proton coupled spectrum and selective proton irradiation experiments. In addition to unambiguous assignment the analysis yielded values for carbon‐proton coupling constants.
Quinazolines and 1,4‐benzodiazepines. XCIII. Synthesis of imidazo[1,5‐a][1,4]benzodiazepines from nitrooximes
Authors: Walser A. , Fryer R. Ian
Published: March 2009

The displacement of the nitro group in nitrooximes by other nucleophiles was used to prepare various 2‐(hydroxyimino)methyl‐ and 2‐(methoxyimino)methyl‐1,4‐benzodiazepines. These compounds were converted to imidazo[1,5‐a][1,4]benzodiazepines bearing a tertiary amine, methoxy or thiomethyl group in the 3‐position.
Synthesis of (1‐substituted piperidin‐4‐yl)‐1H‐benzimidazoles and (1‐substituted piperidin‐4‐yl)‐3,4‐dihydroquinazolines as possible antihypertensive agents
Authors: Obase Hiroyuki , Takai Haruki , Teranishi Masayuki , Nakamizo Nobuhiro
Published: March 2009

Structural modifications of 4‐piperidylbenzimidazolinones (I) by replacing the benzimidazolinone group with other heterocycles (2‐cyanoamino, 2‐ethoxy, and 2‐methylbenzimidazole and 2‐cyanoamino‐3,4‐dihydroquinazoline) has been made and a number of new piperidines (II) were synthesized as potential antihypertensive agents.
Reactions of α‐ketohydrazidoyl halides with some heterocyclic amines. Facile synthesis of arylazo derivatives of fused heterocycles with a bridgehead nitrogen atom
Authors: Abdelhamid Abdou O. , Hassaneen Hamdi M. , Shawali Ahmad S. , Párkányi Cyril
Published: March 2009

Arylazo derivatives of imidazo[2,1‐b]thiazoles, imidazo[1,2‐b]pyrazoles, imidazo[1,2‐b]‐s‐triazoles, imidazo[1,2‐a]pyrimidines, and imidazo[1,2‐a]pyridines were obtained in good yields from α‐keto hydrazidoyl halides and 2‐aminothiazole, 5‐aminopyrazole, 5‐aminotriazole, 2‐aminopyrimidine, and 2‐aminopyridine, respectively (cf. Tables I and II). The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectra, and alternate synthesis wherever possible.
Carbocyclic analogs of anhydrothymidines
Authors: Shealy Y. Fulmer , O'Dell C. Allen , Thorpe Martha C. , Coburn William C.
Published: March 2009

The carbocyclic analog of thymidine (C‐Thymidine, 2) was converted to the analog of 3′‐(O‐methanesulfonyl)‐5′‐O‐tritylthymidine, which was cyclized in alkaline solution or with 1,5‐diazabicyclo[5.4.0]undec‐5‐ene (DBU) to the carbocyclic analog of 5′‐O‐trityl‐2,3′‐anhydrothymidine (6). Hydrolysis of the latter compound produced the carbocyclic analog of all‐cis‐thymidine. C‐Thymidine was also converted to the carbocyclic analog of 3′‐O‐acetyl‐2,5′‐anhydrothymidine (12) by treating the 5′‐O‐methanesulfonyl analog with DBU. Hydrolysis of the anhydro derivative gave back C‐Thymidine. The carbocyclic analog (3) of 3′‐deoxy‐2′‐hydroxythymidine was converted similarly to the corresponding 2,2′‐anhydrothymidine (15) and 2,5′‐anhydrothymidine (21) analogs. As expected, C‐5′‐O‐trityl‐2,2′‐anhydrothymidine formed more readily than did the 2,3′‐anhydrothymidine analog. Hydrolysis of these 2,2′‐ and 2,5′‐anhydrothymidine analogs gave, respectively, the carbocyclic analog of all‐cis‐3′‐deoxy‐2′‐hydroxythymidine and 3.
Synthesis of 7‐phenylpyrimido[5,4‐d][1]benzazepin‐2‐ones
Authors: Chen Wen‐Yean , Gilman Norman W.
Published: March 2009

The syntheses of the 7‐phenylpyrimido[5,4‐d][1]benzazepin‐2‐ones 3, 4, and 5 are described. The 7‐phenyl group was introduced by phenylation of the lactam nitrogen in 10, 13 and 16 respectively. One of these compounds, 5, showed moderate activity as a CNS agent.
Pyrido[2,1‐d][1,5]benzoxazepin — ein neues tricyclisches heteroringsystem
Authors: Bartsch Herbert , Schwarz Otto , Völlenkle Horst
Published: March 2009

Die Synthese and Strukturauflärung eines neuen tricylischen Heteroringsystems werden beschrieben. Die Struktur wurde durch Röntgenstrukturanalyse aufgeklärt.
Synthesis of substituted 2H[1]benzopyrans from coumarins and chromones
Authors: Alberola A. , Ortega A. González , Pedrosa R. , Bragado J. L. Pérez , Rodríguez Amo J. F.
Published: March 2009

A convenient route to substituted 2H[1]benzopyrans is described in which trialkylaluminium compounds are added to coumarins or chromones and the resultant Z‐2‐(3‐hydroxy‐1‐propenyl)phenols are converted by thermal cyclization in the presence of silica gel to 2H[l]benzopyrans.
A new synthesis of 3‐amino‐1‐aryl‐2‐pyrazolin‐5‐ones
Authors: Hyatt John A. , Maggiulli Cataldo A. , French Stephen E.
Published: March 2009

Reaction of ethyl 3‐nitropropionate with aryldiazonium chlorides in basic medium yields ethyl 3‐nitro‐3‐(arylhydrazono)propionates. These α‐nitrohydrazones are converted by catalytic hydrogenation to 3‐amino‐1‐aryl‐2‐pyrazolin‐5‐ones, probably via cyclization of intermediate amidrazones produced in situ. This appears to be the first route to the title compounds that does not use a substituted phenyl hydrazine intermediate and offers advantages in the preparation of pyrazolinones bearing electron‐rich aryl rings.
New reactions of deoxyvasicinone
Authors: Dunn A. D. , Guy E. L. M. , Kinnear K. I.
Published: March 2009

Deoxyvasicinone 1 was shown to react at the 3 position of the pyrrolidine ring with chloroformate esters and benzoyl choloride. Deuterium exchange at this site is also reported.
Unsymmetrically substituted furoxans. VIII. Chloromethylfuroxans
Authors: Calvino R. , Gasco A. , Menziani E. , Serafino A.
Published: March 2009

The two isomeric chloromethylfuroxans have been prepared. Their structures, thermal equilibration and reaction toward thiophenoxide ion are discussed. Kinetics of the 4‐methyl — 3‐methyl isomer thermal conversion are also reported.
Condensation of 2,4(3H,5H)‐furandione with heteroaromatic aldehydes
Authors: Schmidt Diane Grob , Zimmer Hans
Published: March 2009

2,4(3H,5H)‐Furaridione, 1, condenses with heteroaromatic aldehydes in the presence of concentrated hydrochloric acid to yield 3‐(heteroarylmethylene)‐2,4(3H,5H)‐furandiones, 4. The condensation of 1 with acid sensitive aldehydes, including 2‐furanacroleine and N‐methylpyrrole‐2‐carboxaldehyde proceeded well with 1 as the sole proton source. The E/Z ratio of type 4 compounds was determined by 1H‐nmr spectroscopy.
Reissert compounds and their open‐chain analogs in organic synthesis
Authors: Cooney John V.
Published: March 2009

Reactions of major synthetic interest employing Reissert compounds (1, 2‐dihydro‐1‐acyl‐2‐cyanoquinolines and 1, 2‐dihydro‐2‐aqyl‐1‐cyanoisoquinolines) and related heterocyclic species are surveyed. The chemistry of open‐chain analogs of Reissert compounds (i.e., derivatives of N‐acyl‐α‐aminoacetonitriles) is described and compared with conventional Reissert compounds.
Investigation of the structure and 13C NMR spectrum of 5‐phenylbarbituric acid
Authors: De Meester Patrice , Chu Shirley S. C. , Jovanovic Misa V. , Biehl Edward R.
Published: March 2009

Crystals of 5‐phenylbarbituric acid, 2, are monoclinic, space group C2/c. There are 8 molecules in the unit cell of dimensions a = 20.218(3), b = 7.477(1), c, = 12.443(2), β = 111.54° and V = 1749.6(4) Å3. Full‐matrix least‐squares refinement has reached R = 0.039. This is the first barbiturate reported to exist in the enol form in the solid state. There is extensive hydrogen bonding between adjacent molecules which gives rise to very dense crystals. The 13C‐nmr spectroscopy shows that 2 exists in both enol and keto forms in DMSO solution.
Proton‐ionizable crown compounds. 3. Synthesis and structural studies of macrocyclic polyether ligands containing a 4‐pyridone subcyclic unit
Authors: Bradshaw Jerald S. , Nakatsuji Yohji , Huszthy Peter , Wilson Bruce E. , Dalley N. Kent , Izatt Reed M.
Published: March 2009

New proton‐ionizable macrocyclic polyether ligands containing the 4‐pyridone subcyclic unit have been prepared by reacting 4‐THP blocked‐2,6‐pyridinedimethanol with various oligoethylene glycol ditosylates. The 18‐crown‐6 ligand containing the 4‐pyridone subcyclic unit, 4, forms stable complexes with alkali metal and organic ammonium cations. The crystal structure of 4 proves the 4‐pyridone structural unit. The crystal structure of the potassium thiocyanate complex of 4 is also reported and shows the complex to contain the 4‐hydroxypyridine unit.
Fused s‐triazino heterocycles. XIII. 1,3,7,10,11c‐Pentaazabenz[de]‐anthracene and 1,3,7,10,11,13,13d‐heptaazabenz[de]cyclopenta[H]‐anthracene, two new ring systems
Authors: Shaw John T. , Acciai Guy F. , Babin James E. , Sensenig Lori A.
Published: March 2009

The synthesis of the title compounds 5a‐c and 6a‐c is described using, 2,6‐diaminopyridine as starting material. The key intermediates are 2‐t‐butyl‐4‐cyano‐5(2‐dimethylaminoethenyl)‐1,3,6,9b‐tetraazaphenalene 4 and 10‐amino‐2‐t‐butyl‐10,11‐dihydro‐11‐imino‐1,3,7,10,11c‐pentaazabenz[de]anthracene 5c.
Aminosäuren als synthesebausteine von pyrrolo[1,2‐a]‐ und [2,3‐d]anellierten heterobicyclen
Authors: Sinambela James M. , Zimmermann Werner , Roth Hermann J. , Eger Kurt
Published: March 2009

Es wird über die Möglichkeit berichtet, natürlich vorkommende Aminosäuren als bifunktionelle Bausteine zur Heterocyclensynthese einzusetzen.
Mutagenic heterocyclic nitrogen compounds related to protein pyrolysates. V. Electron impact fragmentation of L‐glutamic acid and related dipyrido[1,2‐a:3′,2′‐d]imidazoles
Authors: Saint‐Ruf Germain , Loukakou Bernard , Hebert Eric , Keravis GÉRard
Published: March 2009

Six dipyrido[1,2‐a:3′,2′d]imidazole derivatives related to glutamic acid pyrolysates have been studied by mass spectrometry. The data indicate that there are certain ions which are characteristic of the fragmentation of this family of compounds under electron impact. These compounds should thus be amenable to analysis if they were produced during the combustion of foods. In addition, electronolysis of L‐glutamic acid was also studied: the fragmentation pattern of the latter has shown the formation of some known dipyridoimidazoles for temperatures higher than 100°. Similarities between pyrolysis and electronolysis of this acid are discussed.