bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthèse et réactivité de dihydrotriazines et de dihydrotriazolotriazines
Authors: Daunis Jacques , Djouai‐Hifdi Laila , Lopez Hélène
Published: April 2009

Les dihydro‐4,5 triazinones‐3 peuvent ětre préparées de façon générale par hydrolyse basique des methylmereapto‐3 dihydro‐4,5 triazines; parmi toutesles méthodes de méthylation envisagées, action du diazométhane, du sulfate ou de l'iodure de méthyle en présence de méthylate de sodium ou de carbonate d'argent, ou du bromure de méthyle en catalyse par transfert de phase, seule cette derniére conduit aux différents produitsN‐méthylés en position 2 ou (et) 4. L'action de l'acide formique sur l'hydrazino‐3 triméthyl‐5,5,6 dihydro‐2,5 triazine donne un mélange de dihydrotriazolotriazines résultant des deux possibilités de cyclisation. Deux types de synthèse univoque de dihydro triazolo[4,3‐b] triazines sont décrits.
The synthesis of 8‐oxoberbines containing a heterocyclic D‐ring by enamide photocyclizations
Authors: Lenz George R.
Published: April 2009

The photocyclization of 2‐heteroyl‐1‐methyleneyl‐3,4‐dihydro‐6,7‐dimethoxyisoquinolines, where heteroyl = benzofuran, benzo[b]thiophene, coumarin and nicotinoyl, leads to the corresponding 8‐oxoberbines containing a heterocyclic D‐ring. Dehydrogenation can accompany photocyclization depending on the reaction conditions employed, or alternatively DDQ can be used to effect this dehydrogenation.
Hétérocyclisations intramoléculaires par reaction d'oxymereuration V. Oxymercuration intramoléculaire d'alcools γ‐éthyléniques. Synthèse d'alcools spiranniques
Authors: Spéziale Vincent , Lattes Armand
Published: April 2009

L'hétérocyclisation intramoléculaire, par l'acétate mercurique, d'alcools γ‐éthyléniques dont la double liaison est intracyclique et le groupement hydroxy le en γ du cycle, conduit à des éther‐oxydes spiranniques. L'action du borohydrure de sodium sur les chloromercuriques en solution dans du N,N‐diméthylformamide saturé par de l'oxygène, permet d'obtenir les alcools spiranniques correspondants avec de bons rendements.
Dinitrofuran derivatives
Authors: Sitzmann Michael E.
Published: April 2009

The synthesis and properties of twelve 2‐substituted 3,5‐dinitrofurans are described. These derivatives include bromo‐, iodo‐, azido‐, hydroxy‐, amino‐, 3,5‐dinitro‐2‐furanyl‐, 5‐nitro‐2‐furanyl‐, acetamido‐, and carbamate compounds.
Studies on furan derivatives IV. A simple preparation of α‐substituted β‐(5‐nitro‐2‐furyl)ethynyls from α‐substituted β‐(5‐nitro‐2‐furyl)vinylamines
Authors: Tanaka Akira , Usui Toshinao , Yoshina Shigetaka
Published: April 2009

α‐Substituted β‐(5‐nitro‐2‐furyl)ethynyls were conveniently prepared by the deamination of α‐substituted β‐(5‐nitro‐2‐furyl)vinylamines. Also the application of this reaction towardα,β‐bis(p‐nitrophenyl)vinylamine was examined and affordedα,β‐bis(p‐nitrophenyl)ethynyl as the main product.
Tetronic acids and derivatives. Part V. Synthesis of 5‐hydroxy‐1H‐pyrazoles via 4‐hydrazino‐5H‐furan‐2‐ones. Reaction of hydrazines on tetronic acids
Authors: Gelin Suzanne , Pollet Patrick
Published: April 2009

The conversion of tetronic acids 1 to 3(1‐hydroxy alkyl)‐5‐hydroxy‐1H‐pyrazole derivatives 3, 5, 7 and 12 is described. The formation is shown to proceed via base‐catalyzed rearrangement of the intermediate 4‐hydrazino‐5H‐furan‐2‐one derivatives.
Synthesis in the diazasteroid group VIII. Synthetic studies of the 14,17‐diazasteroid system
Authors: Yamazaki Takao , Matoba Katsuhide , Imai Toshio , Castle Raymond N.
Published: April 2009

Two synthetic routes leading to the 14,17‐diazasteroid system have been developed. One of these gives 14,17‐diazagona‐1,3,5(10),6,8,9,11,13(17)heptaene (V), prepared from benzo[f]quinolin‐3(4H)one (I) and ethanolamine. The other route gives 14,17‐diazagona‐1,3,5(10),8,12‐heptaen‐11‐one (XVIa) via the reaction of 2‐tetralone with ethyl 2‐imidazolidinylidenacetate (IXa).
1,2‐ and 1,4‐Diacetoxylation of 1,3‐butadiene via 2,5‐dihydrothiophene 1,1‐dioxide as a probable intermediate
Authors: Tempesti E. , Giuffrè L.
Published: April 2009

Sulphur dioxide has been found to promote a novel liquid‐phase oxidation of 1,3‐butadiene in acetic anhydride with oxygen gas and catalytic amounts of concentrated protic acids (e.g. hydrobromic acid). 1,2‐Diacetoxy‐3‐butene and 1,4‐diacetoxy‐2‐butene together with small amounts of 1‐hydroxy‐2‐acetoxy‐3‐butene and 1‐hydroxy‐4‐acetoxy‐2‐butene are formed in the reaction.
Derivatives of 2,4‐diamino‐6‐methylpteridine
Authors: Montgomery John A. , Piper James R. , Elliott Robert D. , Roberts Eugene C. , Temple Carroll , Shealy Y. Fulmer
Published: April 2009

Eighteen derivatives of 2,4‐diamino‐6‐methylpteridine related to methotrexate and aminopterin have been prepared from 6‐(bromomethyl)‐2,4‐pteridinediamine by nucleophilic displacement reactions. None of these compounds showed any antileukemic acitivity.
1,2,4‐Triazines. Synthesis of selected members of the s‐triazolo[3,4‐f]‐ [1,2,4] triazine and tetrazolo[1,5‐f] [1,2,4] triazine ring systems
Authors: Lovelette Charles A.
Published: April 2009

A convenient synthesis of 3‐amino‐6‐hydrazino‐5(2H)[1,2,4]triazinone 4 has been developed and a study of the reactions of 4 with aliphatic acids, orthoesters and miscellaneous active carbonyl reagents has been undertaken. When 4 was refluxed in either neat acid or orthoester in dimethylformamide, a facile ring closure reaction with the N‐1 nitrogen of the 1,2,4‐triazine ring occurs affording a novel series of 3‐aIkyl(aryl)‐8(5H)‐s‐triazolo[3,4‐f] [1,2,4]triazinones (6–11). Ring closure with carbon disulfide and cyanogen bromide is also reported affording 6‐amino‐3(2H)thio‐8(5H)‐s‐triazolo[3,4‐f] [1,2,4]triazinone 12 and 3,6‐diamino‐8(5H)‐s‐triazolo‐[3,4‐f] [1,2,4]triazinone 14, respectively. In addition 4 has been converted into 3‐amino‐6‐azido‐5(2H)‐1,2,4‐triazinone 15 which was employed in a study of azide‐tetrazole equilibrium affording 6‐amino‐8(5H)tetrazolo[1,5‐f][1,2,4]triazinone 16. Rates for interconversion at various temperatures were measured and an activation energy for the process determined.
Synthesis of 5‐(3,4,5‐trimethoxyphenyl)‐4‐substituted aryl‐3‐hydrazino‐carbonylmethylthio‐4H‐1,2,4‐triazoles as possible antiinflammatory agents
Authors: Jaiswal Rama K. , Parmar Surendra S. , Singh Shiva P. , Barthwal Jayanti P.
Published: April 2009

A series of 5‐(3,4,5‐trimethoxyphenyl)‐4‐substituted aryl‐3‐hydrazinocarbonylmethylthio‐4H‐1,2,4‐triazoles were synthesized and evaluated for their antiprotolytic and antiinflammatory activities.
Dipole moments. Structure and conformation of asymmetrically 4,5‐substituted 1‐(α‐aroyloxyarylideneamino)‐1,2,3‐triazoles
Authors: Rodios N. A. , Alexandrou N. E.
Published: April 2009

The dipole moments of several asymmetrically 4,5‐substituted 1‐(α‐aroyloxyarilideneamino)‐1,2,3‐triazoles, produced by oxidation of bis‐aroylhydrazones of α‐dicarbonyl compounds, were measured in benzene solution. The structure and the probable conformation of each of these compounds was determined by comparing their experimental and theoretical dipole moments. It has been found that when one of the substituents R1 or R2 is an aryl group, it is located at the 4‐position of the triazole ring. Considering the conformation of the ester‐imino function, it has been found to be the same as that of symmetrically substituted derivatives.
A new route for the preparation of pyrazolo[3,4‐c] pyridines
Authors: Migliara Onofrio , Petruso Salvatore , Sprio Vincenzo
Published: April 2009

Catalytic reduction of the oximes of 4‐phenacyl‐3(5)R‐pyrazole‐4‐carboxylic acid esters (4a,b) followed by cyclisalion constitutes a new appraoch to substituted pyrazolo[3,4‐c]pyridines. The starting materials 4a,b were prepared by reaction of ω‐bromoacetophenone oxime and sodium salts of oxalyl derivatives 2a,b and successive action of hydrazine on the obtained products 3a,b. Structural assignments rested upon correct elemental analysis and spectroscopic evidences.
Studies on the synthesis of analgesics. Part 51. Synthesis of 4‐(1‐oxo‐2‐isoindolinyl)phenyl derivatives. [Studies on the syntheses of heterocyclic compounds. Part 779]
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Ishimaru Haruhide , Nakamura Toshihisa , Shirayama Keiko
Published: April 2009

In order to examine their effect on carrageenin‐induced edema in rats, 4‐(1‐oxo‐2‐isoindolinyl)‐phenyl derivatives were synthesized. 2‐Hydroxy‐3‐[4‐(1‐oxo‐2‐isoindolinyl)phenyl]butyramide was found to be more effective than phenylbutazone.
Chiroptical properties of cyclic amines
Authors: Bettoni Giancarlo , Morlacchi Flaviano , Perrone Roberto , Tortorella Vicenzo , Vetuschi Claudio
Published: April 2009

Chiroptical properties of several 2 or 3 monosubstituted azetidines, pyrrolidines and piperidines as free bases and N‐[2‐pyridyl N‐oxide] derivatives has been examined. The absolute configuration can be unambiguously established, independently on the nature of the substituent and the size of the ring, only for 2‐substituted N‐[2‐pyridyl N‐oxide]amine derivatives. This behaviour is explained in terms of limited rotational freedom in these compounds.
2,3,5,6‐Tetramethylmorpholine. III. Synthesis of the enantiomeric pair of the β1‐isomer
Authors: Tarn Sven Hemes
Published: April 2009

The cyclodehydration of optically active N‐benzyl‐3,3′‐iminobis‐2‐butanols with sulfuric acid is described. Morpholines with high optical purity are obtained.
Access to 14C‐Ring labelled phenothiazines. Synthesis of 2‐chlorophenolhiazine‐5a,9‐14C
Authors: Muccino Richard R. , Cupano Joseph , Liebman Arnold A.
Published: April 2009

Through the use of a recently reported ring expansion reaction, a new route to phenolhiazines has been developed suitable for the preparation of ring labelled derivatives. As an example, the preparation of 2‐chloropheno thiazine‐5a,9‐14C (1) is reported. Condensation of cyclohexanone‐2‐14C with 2‐amino‐4‐chlorothiophenol gave the spiro‐2,3‐dihydro‐l, 3‐benzothiazole 4 which was protected by acetylation (5). Treatment of 5 with sulfuryl chloride gave the tetrahydro‐phenothiazine olefin mixture 6 and 7 which was directly converted to labelled 1 via treatment with DDQ in refluxing benzene followed by hydrolysis of the acetyl group.
Phenylation of the 5,11‐diazaditwistane nucleus
Authors: Kozlowski Matthew A. , Broeke Jan Ten , Grabowski Eklward J. J.
Published: April 2009

A simple phenylation of the 5,11‐diazatetracyclo[6.2.2.02,7 04,9]dodecane system (5,11‐diazaditwistane) is described. Phenylative decarboxylation of 5,11‐biscarbethoxy‐5,11‐diazatetracyclo[6.2.2.02,7 .04,9]dodecane‐2,9‐dicarboxylic acid (3) with lead tetraacetate in benzene affords the 2,9‐diphenyl analogue (4). Hydrolysis yields 2,9‐diphenyl‐5,11‐diazatetracyclo‐[6.2.2.02,7.04,9]dodecane (5), whereas lithium aluminum hydride affords the 5,11‐dimethyl analogue (6).
A convenient and rapid synthesis of potassium penicilliantes using EEDQ
Authors: Voldeng A. Nelson , Fifer Janet T. , Brown D. Ray
Published: April 2009

N‐ethoxycarbonyl‐2‐ethoxy‐1,2‐dihydroquinoline (EEDQ, 1) has been utilized as a coupling reagent to attach sterically unhindered acids to the potassium salt of 6‐aminopenicillanic acid (4) at room temperature.

The excellent yields and rapidity of the reaction illustrate the convenience of utilizing 1 as the coupling reagent to directly prepare the potassium salt of certain penicillins.
The reaction of epibromohydrin with hydroxyquinazolin‐2‐(1H)one derivatives. Novel oxazine formation
Authors: Cotter Mary Lou , Bandurco Victor , Wong Elizabeth , Hajos Zoltan G.
Published: April 2009

Epibromohydrin was found to react with 7‐hydroxy‐2‐methylpyrrolo[1,2‐c]quinazolin‐5(6H)‐one (4) in the presence of sodium hydroxide to form the novel oxazine 5. The structure of compound 5 was proven by cmr and pmr analysis.
7,8‐Dihydro‐5(6H)quinolones. Potential intermediates for the synthesis of pumiliotoxic C
Authors: Bennett Gregory B. , Minor Harold
Published: April 2009

An approach to Pumiliotoxin C(1) based on stereoselective hydrogenation of the regioselective condensation products of primary and tertiary vinylogous amides, 7,8‐dihydro‐5(6H)quinolones, is described. The 2‐substituted quinolones fail to undergo complete saturation to the corresponding decahydroquinolines, stopping instead at the hexahydroquinoline oxidation state.
Acylation of heteroaromatic amines. II dibenzoylation of aminopyridines
Authors: Suzuki Toshinobu , Kenbou Naoya , Mitsuhashi Keiryo
Published: April 2009

Three isomeric aminopyridines were reacted with an excess of benzoyl chloride in the presence of an excess of triethylamine, giving the corresponding dibenzoylaminopyridines in high yields. As an application of the dibenzoylation, the aminopyridines were also reacted with phthaloyl dichloride, resulting in appreciable yields of the respective N‐pyridylphthalimides. The rate of the conversion under various conditions was studied with high pressure liquid chromatography in order to investigate the difference in reactivity among the three isomers.
2‐Indolyl ketone synthesis
Authors: Unangst Paul C. , Brown Richard E. , Fabian Arthur , Fontseré Frank
Published: April 2009

The preparation of 2‐indolyl alkyl ketones by reductive cleavage of a β‐keto sulfone or by the reaction of 1‐chloro‐2‐propanone (chloroacetone) with a 2‐aminobenzoic acid derivative is described. The β‐keto sulfone intermediates are prepared by condensation of the carbanion of dimethyl sulfone and indole‐2‐carboxylic acid esters. Lack of reactivity of several 2‐aminobenzoic acids in the 1‐chloro‐2‐propanone process is related to the presence of electron‐withdrawing substituents in the aromatic ring.
Optically active heteroaromatic compounds IX. Preparation, absolute configuration and optical purity of some chiral 3‐alkylindoles
Authors: Menicagli Rita , Malanga Corrado , Lardicci Luciano
Published: April 2009

The Fischer and Brunner reactions as well as the Grignard alkylation of isatin have been used to prepare (S)‐3‐sec‐butyl‐ and (S)‐3‐(2‐methylbutyl)indoles, respectively, starting from (S)‐1‐chloro‐2‐methylbutane. The stereospecificity of the synthetic sequences followed has been investigated and the stereochemical relationships of the title compounds have been established.
Heterocyclic compounds XII. Quinazoline derivatives as potential antifertility agents
Authors: Manhas M. S. , Hoffman W. A. , Bose A. K.
Published: April 2009

Several quinazoline derivatives incorporating a trans‐stillbene moiety were synthesized as potential post‐coital antifertility agents. Some of these compunds showed low level activity in rats.
Synthesis and crystal structure of a covalently hydrated 8‐thia‐1,4‐diazacycl[3.3.2]azine
Authors: Campaigne E. , Huffman J. C. , Selby T. P.
Published: April 2009

Condensation of ethyl 4‐chloroacetoacetate with 4‐amino‐6‐hydroxy‐2‐pyrimidinethiol produced ethyl 3‐hydroxy‐5‐amino‐7‐oxothiazolino[3,2‐a]pyrimidin‐3‐acetate (7a) on crystallization. Subsequent ring closure of 7a produced the tricyclic 6a‐hydroxy‐5,6,6a,7‐tetrahydro‐8‐thia‐1,4‐diazacycl[3.3.2]azin‐2,5‐dione (8). The structure of 8 was confirmed by crystal x‐ray diffraction analysis.
Studies on the chemistry of pharmacologically active heterocycles. Part I. Acid hydrolysis of hydrazino‐1,2,4‐triazine derivatives
Authors: Daneshtalab M. , Khalaj A. , Lalezari I.
Published: April 2009

The acid hydrolysis of 3‐hydrazino‐5,6‐disubstituted‐1,2,4‐triazine, 3,5‐dihydrazino‐6‐substituted‐1,2,4‐triazine, and 2‐hydrazinopyrimidine derivatives was studied. It was found that the reaction proceeded through the formation of 3‐keto and 3,5‐diketo derivatives of the related 2,3‐dihydro, 2,3,4,5‐tetrahydro‐1,2,4‐triazines, and 2‐keto derivatives of 1,2‐dihydropyrimidines. It was concluded from these reactions that in 1,2,4‐triazine derivatives the C‐5 carbon is more reactive than the C‐3 carbon toward nucleophiles. The reaction mechanism is discussed.
Uber die reaktionen der 1,4,7‐triketone mit hydrazin
Authors: Stetter Hermann , Landscheidt Alfons
Published: April 2009

Aus 1,4,7‐Triketonen und Hydrazin entstehen je nach den Reaktionsbedingungen Dihydro‐pyridazinhydrazone 1–8 oder Dihydropyrrolo [1,2‐b]pyridazine 9–19. Letztere werden durch Chloranil zu den Pyrrolo[1,2‐b] pyridazinen 20–23 dehydriert.
The reaction of cationic dyes with disodium cromoglycate
Authors: Spilzer J. C. , Wolff D. A.
Published: April 2009

The reaction of disodium cromoglycale with five cationic dyes: crystal violet, Janus green, methylene blue, methyl green, and safranine, was investigated. Spectroscopic shifts indicated that at low concentration (0.01 mM) all these dyes were able to form complexes (ion paris) with the cromoglycale anion. In addition, the complexes formed by crystal violet and Janus green were extractable into chloroform.
Novel heterocycles. 3. Synthesis of fused 1,3,2‐benzodiazaphosphorin ring systems
Authors: Coppola Gary M.
Published: April 2009

Novel fused tricyclic phosphorus heterocycles 9 and 11 and the tetracycle 15 were synthesized by cyclization of 1‐haloalkyl (or 3‐haloalkyl)‐2,3‐dihydro‐1,3,2‐benzodiazaphosphorin‐4(1H)one 2‐oxides with sodium hydride. Some spectral data of the products are also discussed.
Alkylation studies on 6‐ethyl‐2,3‐dihydrothiazolo‐[3,2‐A] pyrimidine‐5,7‐diones
Authors: Glennon Richard A. , Bass R. G. , Schubert E.
Published: April 2009

The title compound 7b undergoes alkylation with ethyl iodide or ethyl sulfate at the 7‐position yielding the O‐ethylated product 10 rather than 6,6‐diethyl product 8 as reported previously. Reaction of 7b with mesyl chloride gives 13b which on reaction with potassium carbonate in absolute ethanol also gives 10. Treatment of 7b with phosphorus oxychloride gives 11b which on reaction with potassium carbonate or sodium ethoxide in ethanol produced a mixture from which no 10 was isolated. Authentic 8 was prepared by the reaction of 2‐amino‐thiazoline with ethyl diethylmalonyl chloride (20) in THF containing triethylamine or by the reaction of 5,5‐diethyl‐2‐thiouracil (18) with excess 1,2‐dibromoethane.
Synthesis of 2‐(o‐chloropheny)‐ and 2‐(2′,6′‐dichlorophenyl)‐4‐formyl‐1,2,3‐triazoles
Authors: Swartz David L. , El Khadem Hassan S.
Published: April 2009

Mesoaldehyde 1,3‐dioxime was treated with either o‐chlorophenyl‐ or 2,6 dichloro‐phenylhydrazine to give the corresponding 2‐chlorophenylhydrazone. Hydrazones 1a and 1b were treated with acetic anhydride and cyclized to triazoles (3a and 6a) with cesium carbonate. These were then hydrolized to the previously unknown chlorophenyltriazole aldehydes (4a and 4b). They were also converted to a number of acid derivatives, alcohols, and amines.
The thermal rearrangement of thiabenzenes to their isomeric thiopyrans
Authors: Pirelahi Hooshang , Haghgooii Housane
Published: April 2009

The rates of rearrangement in 1‐phenyl‐2,4,6‐tris(p‐methoxyphenyl)thiabenzene (4) and 1‐(p‐tri‐fluoromethylphenyl)‐2,4,6‐triphenylthiabenzene (5) were determined and a crossover experiment was carried out with a mixture of these thiabenzenes. The possibility of 2,4‐migrations in the thiopyran system under the reaction conditions was also studied by examining two samples of thiopyrans. The results indicate an intramolecular rearrangement which involves a 1,2‐ and 1,4‐migration of 5‐aryl groups in thiabenzenes.
Studies on the synthesis of heterocyclic compounds. III. Preparation of some pyrazolo[3,4‐C] [1,5]benzodiazocin‐10(11H)one derivatives
Authors: Plescia Salvatore , Daidone Guiseppe , Sprio Vincenzo
Published: April 2009

Starting from the readly available N‐melhyl‐N‐(1‐phenyl‐3‐R‐pyrazol‐5‐yl)‐2‐nitrobenzamides (1a,b), the pyrazoles, 4‐aeetyl substituted 2a,b, were prepared in high yield. Reduction of 2a gave the amino derivative 4a, which was eyclized to the desired pyrazolo[3,4‐c][1,5]benzodiazo‐cin‐10(11H)one (5a). Compound 2b afforded 5b directly. Compound 5b was also prepared by the action of phosphorus oxychloride on N‐methyl‐N‐(1,3‐diphenylpyrazol‐5‐yl)‐2‐acetamido‐benzamide (6b).
Recherches dans la serie des hydroindolizines fonctionnelles
Authors: Céaléarier Jean‐Pierre , Eskéanazi Christian , Lhornmet Gerard , Maitte Pierre
Published: April 2009

Dans eet article sont décrites des voies d'accès commodes et généralisables de dérivés de l'indulizine possédant deux fonctions réactives sur les carbones 7 et 8 ou 5 et 8.
Action des réartif's électrophiles sur les hydroxy‐3 thiadiazoles‐1,2,4
Authors: Taliani Laurent , Pcrronnet Jacques
Published: April 2009

Les réaetifs électrophiles peuvent se fixer sur l'atome d'oxvgène de l'hydroxyle en 3 on sur I'atome d'azote 2 des hydroxy‐3 thiadiazoles‐1,2,4 (1). Les réactifs qu'on peut considérer comme “durs” (chlorures d'acides) conduisent en prépondérance an premier type de dérivés, 2. Les isocyanates et anhydrides d'acides qui fournissent exclusivement des dérivés du second type, 3, se comportent comme des réaetifs “mous”.
Stereoselective synthesis of substituted piperazines
Authors: Barluenga J. , Nájera C. , Yus M.
Published: April 2009

The treatment of allylarylamines with mercury(II) acetate in tetrahydrofuran followed by a double decomposition reaction with potassium bromide leads to trans‐2,5‐bis(bromomercuriomethyl)‐1,4‐diarylpiperazines (2). The stereochemistry of the reaction products has been elucidated by an 1H‐nmr spectroscopic study of the trans‐2,5‐dimethyl‐1,4‐diarylpiperazines (3) obtained by sodium borohydride reduction of 2 in alkaline media. The course of the reaction strongly depends on the steric demand of the groups attached to either the allylic group or the ortho‐position in the aromatic ring of the starting amine (1).
13C nmr assignments of selected octahydroindolizines
Authors: Sonnet Philip E. , Netzel Daniel A. , Mendoza Robert
Published: April 2009

Several octahydroindolizines including the four geometrical isomers of 3‐butyl‐5‐methyloctahydroindolizine, which is an attractant of Pharaoh's and [Monomorium pharaonis(L.)], have been examined by 1H and 13C nmr spectroscopy. The conformations of these compounds are discussed.
Synthesis of 5‐methylmercaptopyrimidine nucleosides
Authors: Ryu E. K. , Bardos T. J.
Published: April 2009

The synthesis of a series of new nucleosides, including ribo‐, 2′‐deoxyribo‐ and arabinofuranosides of 5‐(S‐methyl)mercapto‐substituted uracil, 4‐thiouracil, and cytosine is described. The synthetic methods employed include condensation reactions of the silylated pyrimidine with blocked sugar halides, as well as transformations of both the base and sugar moieties. The separated α and β anomers were identified by nmr spectra as well as by unambiguous synthetic routes or interconversions.
Meso‐ionic compounds. XI, photochromic 4‐halogeno‐3‐(3‐pyridyl)sydnones
Authors: Greco Claude V. , Mehta Jitendra R.
Published: April 2009

Halogenation of 3‐(3‐pyridyl)sydnone with N‐halosuccinimides in chloroform afforded the 4‐halogeno‐3‐(3‐pyridyl)sydnones where X = CI, Br, I. The 4‐chloro‐ and 4‐bromopyridylsydnones were photochromic. 3‐(3‐Pyridyl)sydnone was obtained in both high yield and purity by dehydration of N‐nitroso‐N‐(3‐pyridyl)glycine with trifluoroacetic anhydride.
Synthesis and thermochemical behaviour of 1H‐1,2‐benzodiazepine‐3‐carboxylic acids
Authors: Garanti Luisa , Zecchi Gaetano
Published: April 2009

The title earboxylic acids, prepared by alkaline hydrolysis of their ethyl esters, thermally decomposed to give ortho‐aminocinnamonitriles and, in few cases, 3‐unsubstituted 1H‐1,2‐benzodiazepines.
Esterification of sterically hindered pyrrole carboxylic acids using dimethyl and diethyl sulfate under mild basic conditions
Authors: Periasamy M. P.
Published: April 2009

A simple and efficient method for the esterification of sterically hindered pyrrole carboxylic acids using dialkylsulfate and anhydrous potassium carbonate is described.
3H‐2,1,3‐benzolhiadiazine 2,2‐dioxide. A novel heterocyclic system
Authors: Pews R. G.
Published: April 2009

A new heterocyclic system, 3H‐2,1,3‐benzothiadiazine 2,2‐dioxide has been prepared via oxidation of the 3,4‐dihydro‐1H‐2,1, 3‐benzothiadiazine 2,2‐dioxides.
An improved synthesis of 2,4,8,10‐tetroxaspiro[5.5]undeeane (pentaerythritol diformal)
Authors: Poshkus Algirdas C.
Published: April 2009

Pentaerythritol diformal is prepared almost quantitatively in less than ten minutes by heating up to about 120° a neat mixture of pentaerythritol with a slight excess of paraformaldehyde containing catalytic amounts of a mineral acid.
Heterocycles. 7. A facile synthesis of 6,7‐dihydroxs‐1,4‐dithiepins
Authors: Weintraub Philip M.
Published: April 2009

Ring expansion by dehydration of 1,3‐dithian‐2‐ylmethanols gives 6,7‐dihydro‐5H‐1,4‐dithiepins.
The synthesis of 5‐azaindole derivatives via mesoionic oxazolium 5‐oxides
Authors: Hershenson Fred M.
Published: April 2009

A synthesis of 5‐azaindole derivatives is described. This synthetic approach involves the preparation of an appropriately substituted pyrrole derivative by a 1,3‐dipolar cycloaddition reaction of dimethyl acetylenedicarboxylate with a mesoionic oxazolium 5‐oxide. The pyrrole intermediate contains a protected β‐aminoethyl substituent, and subsequent removal of the phthalimido protecting group results in cyclization to yield the corresponding 5‐azaindole. This approach has been used for both acyclic and cyclic amino acid precursors of the 1,3‐dipole which is ultimately used in the sequence.
Studies on heterocyclic primary amines, I. reaction of 2‐amino‐5‐aryl‐1,3,4‐oxadiazoles with phosphorus pentachloride
Authors: El‐Deek M. , El‐Badry K. , Abdel‐Wahhab S. M.
Published: April 2009

Stable N‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)phosphorimidic trichlorides (II) are obtained by refluxing 2‐amino‐5‐aryl‐1,3,4‐oxadiazoles (I) with one equivalent of phosphorus pentachloride in dry benzene. The reactions of the phosphorimidic trichlorides were also studied.
Folate antagonists. 14. Synthesis of pyrazino[2,3‐f]quinazoline‐8,10‐diamines and related heterocycles as potential antimalarial agents (1,2)
Authors: Johnson Judith , Elslager Edward F. , Werbel Leslie M.
Published: April 2009

Amination of 5‐chloro‐6‐nitro‐2,4‐quinazolinediamine (2) afforded 6‐nitro‐2,4,5‐quinazolinetriamine (3) which was hydrogenated catalytically to produce 2,4,5,6‐quinazolinetetraamine (5). Condensation of 5 with the requisite diketones afforded 8,9,10,11‐tetrahydropyrimido[5,4‐a]‐phenazine‐1,3‐diamine (6), several pyrazino[2,3‐f]quinazoline‐8,10‐diamines (7–10,13) as well as two pyrimido[4,5‐f]phenazinediamines (11,12). Amination of 2 in the presence of formamide at 120° led to the formation of 9‐nitro‐1H‐pyrimido[4,5,6‐de]quinazolin‐5‐amine (4). None of these compounds showed suppressive activity when tested parenterally against lethal Plasmodium berghei infections in mice. When tested against various bacteria in vitro, 7 and 10 exhibited activity against Streptococcus faecalis at a concentration below 2.5 μg./ml.
Synthesis of a bridgehead nitrogen system. Imidazo[1,5‐b]pyridazine derivatives
Authors: Migliara Onofrio , Petruso Salvatore , Sprio Vincenzo
Published: April 2009

3,4‐Dibenzoyl‐2‐oxobutyrate 4‐semicarbazone (6a), ethyl 2,4‐dioxo‐3‐phenacylvalerate 3‐semicarbazone (6b) and diethyl phenacyloxalectate 3‐semicarbazone (6c) via acid catalysed intramolecular cyclization afforded 2‐phenyl‐4‐R‐3H‐imidazo[1,5‐d]pyridazine‐5,7‐(6H)diones (8d,e,f). Elemental analyses and spectroscopic data (ir, nmr, ms) were in good agreement with the assigned structures.
Pyrimidine derivatives and related compounds. A novel synthesis of pyrimidines, pyrazolo[4,3‐d]pyrimidines and isoxazolo[4,3‐d] pyrimidine
Authors: Elnagdi Mohamed Hilmy , Fahmy Shereif Mahmoud , Hafez Ebtisam Abdel Aziz , Elmoghayar Mohamed Riffaat Hamza , Amer Samir Abdel Rahman
Published: April 2009

Benzoylacetonitrile (II) reacted with trichloroacetonitrile (III) to yield the β‐amino‐β‐trichloromethylacrylonitrile IV. Compound IV reacted with hydrazine hydrate to yield 5‐amino‐4‐cyano‐3‐phenylpyrazole (V) and with 2‐aminopyridine to yield the aminopyridine derivative VIII (cf., Chart I). Compound IV reacted with III to yield 2,4‐bis(trichloromethyl)‐5‐cyano‐6‐phenylpyrimidine (I) which could be converted into a variety of pyrazolo[4,3‐d]pyrimidine derivatives by treatment with hydrazine hydrate under a variety of different experimental conditions (cf., Chart II).
Synthesis of some isomeric 4‐ethoxycarbonyl‐3‐and 5‐(1‐ and 2‐hydroxyalkyl)‐1,3‐ and 1,5‐dimethylpyrazoles from 3‐(2H)furanones and 2,3‐dihydro‐4‐pyrones
Authors: Gelin Suzanne , Deshayes Christian , Chabannet Michel
Published: April 2009

The title compounds were prepared by reaction of 3‐(2H)furanones and 2,3‐dihydro‐4‐pyrones with methylhydrazine or alternatively by methylation of the corresponding N‐unsubstituted pyrazoles. 13C and 1H nmr were used to assign the isomeric 3‐methyl or 5‐methyl structures.
Synthesis of 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives
Authors: Santilli Arthur A. , Morris Robert L.
Published: April 2009

Several new 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives have been synthesized. A typical example, 3‐[(4‐chlorophenylsulfonyl)methyl]‐1,2,4‐oxadiazole‐5‐carboxylic acid ethyl ester (2c), was prepared from the reaction of 2‐(4‐chlorophenylsulfonyl)acetamide oxime (1c) with ethyl oxalyl chloride. The hydrazide derivative (3f) showed antihypertensive activity in rats. Various structural modifications to improve activity are discussed.
Dérivés de l'imidazo[2,1–b] thiazole. IV. Réarrangements au cours de la condensation de β‐dicétones α‐bromées avec l'amino‐2 thiazole et la mercapto‐2 imidazoline
Authors: Robert Jean FranÇOis , Panouse Jacques J.
Published: April 2009

Au cours de la condensation des β‐dicétones α‐bromées sur l'amino‐2 thiazole et la mercapto‐2 imidazoline, la formation d'acétyl (ou benzoyl) imino‐2 acétonyl (ou phénacyl)‐3 thiazolines et d'acétyl (ou benzoyl)‐1 acétonyl (ou phénacyl) thio‐2 imidazolines est observée. L'obtention de ces composés résulte d'un réarrangement après ouverture, par attaque nucléophile, d'une carbinolamine intermédiaire. Ce réarrangement est univoque dans le cas de β‐dicétone dis‐symétrique.
Triazino‐1,2,4‐[4,5‐a] indoles. V. Etude du dioxo‐1,4 tetrahydro‐1,2,3,4 triazino‐1,2,4‐[4,5‐a] indole
Authors: Maume Daniel , Lancelot Jean‐Charles , Robba Max
Published: April 2009

Le dioxo‐1,4 tétrahydro‐1,2,3,4 triazino‐1,2,4‐[4,5‐a] indole (1) est synthétisé soit par cyclisation du N‐carbéthoxyhydrazide de l'acide indole carboxylique‐2 (4) soil par réarrangement en milieu alcalin de l'(indolyl‐2)‐2 oxadiazolone‐5 (6). Les réactions de méthylation du dérivé 1, effectuées au moyen du sulfate diméthylique el du diazométhane, ont conduit à des mélanges de dérivés O‐méthylés et N‐méthylés qui sont séparés et dont la structure est établie. Ils sont utilisés comme modèles pour l'étude de la tautoméric du dilactame 1 qui présente en solution une forme lactame‐lactime 1a.
Carbon‐13 and proton magnetic resonance spectra of 2,4‐disubstituted 3,3‐diphenyltetrahydrofurans derived from isomethadone and isomethadol
Authors: Williams David A. , Makriyannis Alexandros
Published: April 2009

Proton and carbon‐13 nmr spectra forcis‐andtrans‐2‐ethyl‐3,3‐diphenyl‐4‐methyltetrahydrofurans and 2‐ethylidene‐3,3‐diphenyl‐4‐methyltetrahydrofuran, derived from the pyrolysis of the quaternary ammonium salts of the diastereomeric isomethadols and isomethadone, respectively, are reported.1H and13C chemical shifts and1H‐1H coupling constants have been assigned in each case. The isomeric teterahydrofurans have been analyzed in terms of a half‐chair conformation, and an envelope conformation for the ethylidene derivative.
The synthesis of 6,9‐dioxo‐, 6,9‐ and 7,9‐dihydroxyehlorpromazines, possible metabolites of chlorpromazinem
Authors: Suzuki Joseph K. , Zirnis Aija , Manian Albert A.
Published: April 2009

The syntheses of dioxogenated chlorpromazines 1, 2, and 3 via the reductive ring closure of substituted nitrodiphenyl sulfides are described.
Synthesis of N‐ethoxycarbonyl‐7‐azabicyclo[4.2.1]nonane and N‐ethoxycarbonyl‐9‐azabicyclo[4.2.1]nonane
Authors: Loreto M. Antonietta , Pellacani Lucio , Tardella Paolo A.
Published: April 2009

The synthesis of N‐ethoxycarbonyl‐7‐azabicyclo[4.2.1]nonane and N‐ethoxycarbonyl‐9‐azabicyclo[4.2.1]nonane, starting from bicyclo[5.1.0]octan‐2‐one, is described. The key step is the cyclopropyl ring fission by pyridinium chloride.
Photolysis of 1‐o‐iodobenzoylbenzimidazoles
Authors: Nakano Tatsuhiko , Martin A.
Published: April 2009

Irradiations of 1‐o‐iodobenzoyl‐2‐methylbenzimidazole, 1‐o‐iodobenzoylbenzimidazole, and 1‐o‐iodobenzoyl‐5,6‐dimethylbenzimidazole in benzene gave compounds 1, 2, and 3, respectively. The fragmentation patterns of these latter compounds upon electron impact are also reported with the aid of high resolution mass spectrometry.
Streptonigrin and related compounds IV. Precursors for the a‐ring
Authors: Rao Koppaka V. , Kuo Hsien‐Saw
Published: April 2009

The synthesis of streptonigrin or its tricyclic (ABC) analogues by the Friedlander condensation requires a 2‐nitrobenzaldehyde with all the necessary functionalities. A number of alternative syntheses are examined. It is shown that oxidation of 8‐amino‐5,6‐dimethoxy‐2,2‐pyridylquinoline leads to 8‐amino‐2,2‐pyridylqunoline‐5,6‐dione instead of 6‐methoxy‐2,2‐pyridylquinoline‐5,8‐dione. The synthesis of two useful precursors: 4‐bromo‐3‐hydroxy‐5,6‐dimethoxy‐2‐nitrobenzaldehyde and 4‐bromo‐3‐hydroxy‐5‐methoxy‐2‐nitrobenzaldehyde is described.
2,3,5,6‐Tetramethylmorpholine. IV. The observation of a new cyclization mechanism
Authors: Hernestam Sven
Published: April 2009

A new type of cyclization, implying the simultaneous inversion of configuration at the reacting carbon atom and at the carbon atom bearing the nucleophilic group, is observed when two 3,3′‐iminobis‐2‐butanols are dehydrated by 70% sulfuric acid at 140–150°.
Ring‐chain tautomerism of acetone N‐methylated thiosemicarbazones
Authors: Uda Masayuki , Kubota Seiju
Published: April 2009

Ring‐chain tautomerism of acetone N‐methylated thiosemicarbazones was studied by nmr spectroscopy. Acetone thiosemicarbazone, acetone 2‐methylthiosemicarbazone, and acetone 4‐methylthiosemicarbazone exist as chain forms in DMSO‐d6 and ring forms in deuteriotrifluoroacetic acid. However, the compound obtained by reaction of acetone with 2,4‐dimethylthiosemicarbazide exists only as the ring form 3,5,5‐trimethyl‐1,3,4‐thiadiazolidine‐2‐methylimine both in DMSO‐d6 and in deuteriotrifluoroacetic acid, due to steric hindrance of the three methyl groups.
Synthesis of 1‐(2,4,6‐trichlorophenyl)‐3‐(3‐nitro‐ and 2‐chloro‐5‐nitroanilino)‐5‐pyrazolones
Authors: Tracy David J.
Published: April 2009

A convenient one flask synthesis of 1‐aryl‐3‐nitroanilino‐5‐pyrazolones in yields of 60–65% is described. Synthesis involves initial reaction of ethyl 3‐ethoxy‐3‐iminopropionate hydrochloride and a nitroaniline in methanol producing an imidate ester. The imidate ester is then reacted with an arylhydrazine forming an amidine. The amidine is then cyclized with base.
Oxidation of pyridines with copper sulfate
Authors: Tomasik Piotr , Woszczyk Adam , Abramovitch Rudolph A.
Published: April 2009

Oxidation of pyridine, 3‐picoline, 3,5‐lutidine, quinoline, isoquinoline and acridine with hydrated copper sulfate at high temperatures gives the corresponding pyridones, possibly via the intramolecular reaction of a base ‐ Cu(II) complex. Overall conversions are rather poor. 2‐ And 4‐picolines and their methyl homologues undergo some demethylation under these conditions and some picolinic acid is isolated from 2‐picoline. 2‐ And 4‐ethylpyridines give both pyridine and 2‐ and 4‐picoline, respectively.
Catalytic effect of ammonium chloride on the synthesis of imidate esters
Authors: Tracy David J.
Published: April 2009

Preparation of imidate esters by reaction arylamines containing electron withdrawing groups with ethyl 3‐ethoxy‐3‐imino‐propionate in methanol is described. Evidence is presented for an orthoester intermediate. The unusual catalytic effect of ammonium chloride is discussed.
Benzo[b]thiophene derivatives. XXV. Condensation and reductive alkylation of 3‐aminoalkylbenzo[b]thiophenes with formaldehyde
Authors: Campaigne E. , Homfeld E.
Published: April 2009

The reductive alkylation of 3‐aminomethylbenzo[b]thiophene by the Eschweiler‐Clarke (formaldehyde‐formic acid) method and of 3‐β‐aminoethylbenzo[b]thiophene by the Borch (formaldehyde‐cyanoborohydride) method proceeded in good yields. However, the Eschweiler‐Clarke reaction with 3‐β‐aminoethylbenzo[b]thiophene gave the Pictet‐Spengler cyclized product, N‐methyl‐1,2,3,4‐tetrahydrobenzo[b]thieno[2,3c]pyridine. Mechanistic aspects of the latter reaction were investigated.
Synthesis of 1,2,3,4,4a,5‐hexahydropyrido[1′,2′:4,5][1,4]oxazino[2,3‐b]quinoxaline derivatives
Authors: Wright William B. , Morton George O. , Tomcufcik Andrew S.
Published: April 2009

Reactions of 2,3‐dichloroquinoxalines with 2‐(hydroxymethyl)piperidine resulted in a series of 1,2,3,4,4a,5‐hexahydropyrido[1′,2′:4,5][1,4]oxazino[2,3‐b]quinoxaline derivatives. The structures of the products were confirmed by nmr and x‐ray crystallography.
Oxidation of bis‐arylacetylhydrazones of α‐dicarbonyl compounds
Authors: Stephanidou‐Stephanatou J. , Varella E. , Micromastoras E. D. , Alexandrou N. E.
Published: April 2009

Oxidation of the title compounds (IV) with lead tetraacetate gives, instead of the expected 1‐(α‐arylacetyloxyarylethyleneamino)‐1,2,3‐triazoles, the amides (V), 1‐(N‐arylacetylamino)‐1,2,3‐triazoles, as the main products in moderate yields. The reaction mechanism is discussed.
Selenium heterocycles. XXIV (1). 4‐Substituted vinyl and 4‐phenyl‐1,3‐butadienyl‐1,2,3‐selenadiazoles and related compounds
Authors: Lalezari Iraj , Shafiee Abbas , Sadeghi‐Milani Shahnaz
Published: April 2009

A series of 4‐aryl (or heteroeyclic)‐3‐buten‐2‐one semicarbazones as well as 6‐phenyl‐3,5‐hexadien‐2‐one semicarbazone were reacted with selenium dioxide to give the corresponding 4‐substituted vinyl and 4‐phenyl‐1,2‐butadienyl‐1,2,3‐selenadiazoles. The selenadiazoles were converted to the corresponding 1,4‐diselenafulvenes. Pyrolysis of 4‐styryl‐1,2,3‐selenadiazole gave 2,5‐distyrylselenophene.
Studies on furan derivatives. V. A novel ethoxycarbonylmethylation of the 5‐nitro‐2‐furan ring in the reaction of α‐(2‐furyl)‐β‐(5‐nitro‐2‐furyl)ethynyl with N‐ethoxycarbonylmethylpyridinium ylide
Authors: Tanaka Akira , Usui Toshinao
Published: April 2009

An unexpected product, 1‐(4‐ethoxycarbonylmethyl‐5‐nitro‐2‐furyl)‐2‐(2‐furyl)‐3‐ethoxycarbonyl‐indolizine was obtained by the reaction of α‐(2‐furyl)‐β‐(5‐nitro‐2‐furyl)ethynyl with N‐ethoxy‐carbonylmethylpyridinium ylide in N,N‐dimethylformamide, together with 1‐(5‐nitro‐2‐furyl)‐2‐(2‐furyl)‐3‐ethoxycarbonylindolizine.
5‐Oxo‐1H‐4,5‐dihydro‐1,2,4‐benzotriazepines. Chemical behavior towards alkylating, acidic and alkaline agents
Authors: Bianchi Mario , Häusermann Enrico , Rossi Silvano
Published: April 2009

The chemical behavior of 4‐methyl and 4‐phenyl‐5‐oxo‐1H‐4,5‐dihydro‐1,2,4‐benzotriazepines towards methylating and acidic agents has been investigated. The 4‐methyl derivative, when treated with methyl fluorosulfonate furnished, after crystallization from water, a quaternary salt (2,4‐dimethyl‐5‐oxo‐1H‐4,5‐dihydro‐1,2,4‐benzotriazepinium fluorosulfonate), whereas from the 4‐phenyl derivative, a complex mixture was obtained, which, after boiling with water, afforded 2‐methylindazolone, aniline fluorosulfonate and formic acid. In acidic medium the 4‐methyl derivative underwent an isomerization reaction yielding 1‐imino‐3‐methylquinazolin‐4‐one, but the 4‐phenyl derivative exclusively yielded products resulting from ring opening. In alkaline medium, both compounds gave hydrolytic cleavage products.
The cyelodesulfurization of thio‐compounds. Part XVII. Synthesis of some novel 2‐substituted amino‐3,4‐dihydro‐5H‐1,3,4‐benzotriazepin‐5‐ones by cyelodesulfurization of thiosemicarbazides with dicyclohexylearbodiimide (DCCD)
Authors: Omar A.‐Mohsen M. E. , Ashour F. A. , Bourdais Jacques
Published: April 2009

A simple method for the synthesis of a novel series of 2‐substituted amino‐3,4‐dihydro‐5H‐1,3,4‐benzotriazepin‐5‐ones (11–16) has been established through two routes. The first involving the cyelodesulfurization of the thiosemicarbazides (3–8) with DCCD and the second reacting mixtures of the acid hydrazide 1 with a variety of the isothiocyanates 2 and DCCD. The structure of the cyclized products was confirmed by nmr and mass spectra.
Studies on the synthesis of heterocyclic compounds. V. Preparation of 1,3,2‐benzoxathiaphosphole, arsole and stibole derivatives by exchange methods
Authors: Anchisi Carlo , Corda Luciana , Maccioni Antonio , Podda Gianni , Secci Mario
Published: April 2009

A new convenient method for synthesis of heterocyclic compounds of five‐membered rings containing an O‐M‐S (M = P, As, Sb) linkage is described. The compounds IIIa‐c, IVa‐b, Va‐b, Viand VII were prepared starting from 2,2‐dimethyl‐1,3,2‐benzoxathiastannole (II) and derivatives of phosphorus, arsenic and antimony. The structures of newly prepared compounds was determined by elemental analysis, spectroscopic methods (ir, nmr and ms) and comparison with authentic samples obtained via a different manner.
Research on nitrogen heterocyclic compounds. XII. Synthesis of 5H‐pyrrolo[1,2‐b][2]benzazepine derivatives
Authors: Stefancich Giorgio , Artico Marino , Massa Silvio , Vomero Salvatore
Published: April 2009

Several routes to the synthesis of the unknown 5H‐pyrrolo[1,2‐b][2]benzazepine ring system have been explored. 1‐(2‐Cyanobenzyl)pyrrole was useful as starting material to obtain 1‐(2‐earboxymelhylbenzyl)pyrrole and 1‐(2‐chloromethylbenzyl)‐2‐pyrrolecarboxaldehyde. Poly‐phosphoric acid catalyzed intramolecular cyclization of the former substance and treatment of the latter compound with potassium cyanide led to 11‐oxo‐10,11‐dihydro‐5H‐pyrrolo[1,2‐b]‐[2]benzazepine and to 10‐cyano‐5H‐pyrrolo[1,2‐b][2]benzazepine, respectively. Starting from these materials the synthesis of the parent nucleus 5H‐pyrrole[1,2‐b][2]benzazepine and its 10,11‐dihydro‐ and 1,2,3,10,11,11a‐hexahydroderivatives has been realized.
The nature of the fragmentation step for decarboxylation in heterocyclic carboxylic acids
Authors: Salmón M. , Villarino O. , Jiménez A. , Cortés E. , Damian C.
Published: April 2009

A mechanism of fragmentation for five membered heterocyclic‐substituted acids is proposed. The suggested four centered transition state for the CO2 elimination is based on the resulting deuterium‐labelled ions.
Ipso nitration. Nitrodeformylation reactions in nitrothiophenealdehydes
Authors: Cogolli Pietro , Maiolo Filippo , Testaferri Lorenzo , Tiecco Marcello , Tingoli Marco
Published: April 2009

Nitration of 4‐nitro‐2‐thiophenealdehyde afforded 2,4‐dinitrothiophene and small quantities of 4,5‐dinitro‐2‐thiophenealdehyde; 5‐nitro‐2‐thiophenealdehyde gave instead 3,5‐dinitro‐2‐thiophenealdehyde as the main product and some 2,5‐dinitrothiophene. The two dinitrothiophenes form through a nitrodeformylation reaction which represents an interesting example of the nitration at an ipso position in a strongly deactivated substrate.
Proximate functionality induced restricted rotation of a carbamate: 2,6‐Dicarbethoxy‐7‐methoxy‐5,6‐dihydropyrrolo[1,2‐c]quinazoline
Authors: Cotter Mary Lou , Bandurco Victor , Wong Elizabeth
Published: April 2009

The 6‐carbethoxy group of 2,6‐dicarbethoxy‐7‐methoxy‐5,6‐dihydropyrrolo[1,2‐c]quinazoline (4) is observed by nmr to experience an unusual steric barrier to free rotation about the N‐CO bond which arises from the proximate 7‐methoxy group.
Novel nitroimidazo[2,1‐b]oxazole formation from reaction of 2,4(5)‐dinitroimidazole with oxiranes
Authors: Sehgal Raj K. , Agrawal Krishna C.
Published: April 2009

A novel reaction for the synthesis of 2,3‐dihydroimidazo[2,1‐b]oxazoles has been described by condensation of 2,4(5)‐dinitroimidazole with a series of oxiranes.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)dione (isatoic anhydride). 6. Synthesis of spiro[indoline‐2,2′(1′H)quinazolines]
Authors: Coppola Gary M. , Damon Robert E.
Published: April 2009

The reaction of isatoic anhydrides with potassium cyanide is described. The stoichiometry of the reactants and reaction times dictate the formation of either 2‐imino‐3‐indolinones or spiro[indoline‐2,2′(1′H)quinazolines]. Some spectral data is also discussed.
(E) and (Z)‐α‐hydroxy and α‐methoxyimino‐4‐nitro‐1H‐imidazole‐1‐acetic acids and esters. Spectral properties, conformations and photoisomerization of the new compounds
Authors: Elitropi Guglielmo , Pantò Ezio , Tricerri Silvia
Published: April 2009

Detailed experimental procedures are given for the preparation of the stereoisomeric (E)‐ and (Z)‐methyl‐α‐hydroxy and α‐methoxyimino‐4‐nitro‐1H‐imidazole‐1‐acetates and of the related acids. (Z)‐Isomers have been prepared by synthesis. (E)‐Isomers have been obtained only by photoisomerization. Decarboxylation of the acids left the corresponding aldehydes which are ideal compounds for structural studies and configurational assignments.
Condensed pyridazines. Part IV. Reductive cyclization of (Z)‐methyl 3‐(6‐azido‐3‐chloro‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazin‐5‐yl)‐2‐rnethylacrylatc (I) to pyrido[2,3‐c] pyridazines and the acid‐catalysed cyclization of I to a pyrano[2,3‐d] pyridazine
Authors: Maeba Isamu , Mori Kazumi , Castle Raymond N.
Published: April 2009

Reduction followed by cyclization of (Z)‐methyl 3‐(6‐azido‐3‐chloro‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazin‐5‐yl)‐2‐methylacrylate (I) to pyrido[2,3‐c]pyridazines by treatment with triethyl phosphite or hydrazine hydrate as the reducing agents is described. Compound I was also reductively cyclized with sodium borohydride. Treatment of I with concentrated sulfuric acid gave 8‐chloro‐3,6‐dimethyl‐2,5‐dioxo‐5,6‐dihydro‐2H‐pyrano[2,3‐d] pyridazine (VII) which also could be synthesized by another independent route. A mechanism for the cyclization is proposed.
2‐(Methylpyridyl or quinolyl)benz‐X‐azoles, salts and polymethine dyes
Authors: Barni Ermanno , Savarino Piero
Published: April 2009

2‐(Methylpyridyl or quinolyl)benz‐X‐azoles were synthesized by the general reaction between carboxylic acids and o‐bifunctional compounds. By reaction of the bases with methyl iodide, a series of salts were recovered which were identified and when possible transformed into the corresponding polymethine dyes. The main spectroscopic features of these compounds are briefly discussed.
Quaternary salts from 2‐(methylpyridyl or quinolyl)benzimidazoles and related polymethine dyes
Authors: Barni Ermanno , Savarino Piero
Published: April 2009

The quaternisation of 2‐(methylpyridyl or quinolyl)benzimidazoles with methyl iodide leads to a variety of salts depending on the relative position of the nuclei and on the experimental conditions: N‐methylpyridinium, N‐methylquinolinium, methyl and 1,3‐dimethylbenzimidazolium iodides, and hydroiodides were isolated. Cyanine dyes were prepared from N‐methylpyridinium and N‐methylquinolinium methiodides. The main spectrospcopic features of these compounds are briefly discussed.
Synthesis of peptides containing 1,2,3,4‐tetrahydroquinoline‐2‐carboxylic acid. Part 3. Cyclization of dipeptides and amides with acetic anhydride
Authors: Zecchini Giampiero Pagani , Paradisi Mario Paglialunga
Published: April 2009

Treatment of protected dipeptides containing 1,2,3,4‐tetrahydroquinoline‐2‐carboxylic acid with acetic anhydride affords only 1H,3H,5H‐oxazolo[3,4‐a]quinolin‐3‐one derivatives. The formation of a‐acylaminomethylketones, arising from the competitive Dakin‐West reaction, was generally observed when the cyclization procedure was extended to some amides of the cyclic imino acid. The preferential stabilization of one of two probable mesoionic intermediates seems to determine the preferred pathway.
Synthesis of schiff bases derived from 2,4,6‐trimethoxypyrimidine‐5‐carboxaldehyde
Authors: Delia Thomas J. , Wilcox Thomas M. , Otteman Ronald R.
Published: April 2009

Schiff bases have been formed with methyl‐, methoxy‐, nitro‐ and unsubstituted anilines and 2,4,6‐trimethoxypyrimidine‐5‐earboxaldehyde.