bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon‐13 NMR study of 1‐methyl‐3‐phenyl‐4‐diazo‐5‐benzoylamidopyrazole and other model pyrazole compounds
Authors: Cecchi Lucia , Melani Fabrizio , De Sio Francesco
Published: April 2009

A 13C nmr study of a diazo, of two diazonium salts and of some other model pyrazole compounds is reported. It is found that the C‐4 diazo carbon is more shielded than the normal sp2 pyrazole hybridized carbon, while its diazonium salt is more deshielded. The electron density on the C‐4 of the diazopyrazole is probably due to the positive charge on the terminal nitrogen. Thus the 13C chemical shift values allowed us to understand the chemical behaviour of a compound of potential antitumor activity.
2‐Azabicyclo[2.2.1]heptane‐3‐carboxylic acid ‐ A bicyclic proline
Authors: Gaitanopoulos Dimitri E. , Weinstock Joseph
Published: April 2009

Diels‐Alder reaction of cyclopentadiene and methyl N‐carbobenzyloxy‐2‐iminoacetate generated in situ from methyl 2‐chloro‐N‐carbobenzyloxyglycinate by triethylamine gave the N‐carbobenzyloxy unsaturated bicyclic proline ester. This was converted in two steps to 2‐azabicylo[2.2.1]heptane‐3‐carboxylic acid. In contrast to N‐carbobenzyloxy‐L‐proline methyl ester, the corresponding bicyclic proline ester was resistant to hydrolysis catalyzed by carboxypeptidase Y.
Photochemistry of host‐guest complexes. VIII. The photoreaction of pyrazinedicarbonitrile derivatives having a crown ether moiety in the presence of an ω‐diethylamino‐1‐alkanaminium salt
Authors: Tada Masaru , Hamazaki Hirohide , Tsuzuki Koichi
Published: April 2009

Irradiation of 5‐[(benzo‐18‐crown‐6)‐4′‐yl]pyrazine‐2,3‐dicarbonitrile and 5‐(3,4‐dimethoxyphenyl)pyrazine‐2,3‐dicarbonitrile in the presence of ω‐diethylamino‐l‐alkanaminium ion caused the reductive decyanation to give pyrazinemonocarbonitrile derivatives. The reaction is initiated by a single electron transfer from the tertiary amino group of the diamine. The complex formation between the crown ether moiety and the ω‐ diethylamino‐l‐alkanaminium ion enhances the photoreaction.
Studies related to cephalosporins. Part 2 . Displacement reactions on 3‐bromomethylcephems with salts of carboxylic acids
Authors: Botta Maurizio , De Angelis Francesco , Grgurina Ingeborg , Marzi Mauro , Nicoletti Rosario
Published: April 2009

The reactivity of Δ3‐ and Δ2‐3‐bromomethylcephems toward carboxylate nucleophiles has been studied. The Δ3‐bromomethylcephem 1, less reactive than the Δ2‐analogue 4, is converted in high yields into 3‐acyl‐oxymethyl‐3‐cephems 2a‐d, generally with no isomerization of the double bond, only within a narrow range of conditions. In particular, the Δ3‐7‐aminocephalosporanic acid (7‐ACA) derivative 2a has been obtained as the only product in 91% yield by treatment of 1 with triethylammonium acetate in acetic acid.

The Δ2‐bromomethyl‐cephem 4 is easily converted into the Δ2‐acyloxymethyl‐cepheras 5a‐d without double bond isomerization, in very high yields.
The synthesis and chemistry of some bis‐aziridinylketones and their spectral study
Authors: Lin Tay‐Yean , Kingsbury Charles A. , Adelfang Jules , Cromwell Norman H.
Published: April 2009

The synthesis and spectral characteristics of certain bis(1‐alkyl‐3‐phenyl‐2‐aziridinyl)ketones are reported. The reactions of 1,2,4,5‐tetrabromo‐1,5‐diphenyl‐3‐pentanone (2) with primary amines are assumed to have a mechanism similar to that of a simple dibromo‐ketone. The so‐called cis, cis‐ or trans, trans‐configurations of the bis‐aziridinylketones were determined by 1H and 13C nmr spectra.
Some new aspects on the chemistry of 1,4‐benzoxazines
Authors: Chioccara Francesco , Novellino Ettore
Published: April 2009

3‐Methyl (3a) and 3‐t‐butyl‐1,4‐2H‐benzoxazine (3b) were synthesized by cyclization of the appropriate acetamidoketone (Scheme 1). The former is a highly unstable molecule which rapidly converts in an intractable mixture, while the latter slowly undergoes aerial oxidation affording the hemiacetal 4. The 4H‐forms of the same 3‐methyl (6a) and of the parent 1,4‐benzoxazine (9) could be obtained as 4‐acetyl derivatives. This latter, by hydrolysis, gave the cyclic trimer 10.
Preparation of cyclohepta and benzo[ef]cycl[3.2.2]azines
Authors: Noguchi Michihiko , Tanigawa Noriyuki , Kajigaeshi Shoji
Published: April 2009

Some cyclohepta[ef]cycl[3.2.2]azines were prepared from cyclohepta[hi]indolizines and electron deficient acetylenes in the presence of appropriate oxidants. Also, benzo[ef]cycl[3.2.2]azines were obtained similarly in good yields.
4,5‐Dibenzyloxybenzyne as a synthon for diels‐alder reactions. The synthesis of 6,7‐dihydroxy‐1,4‐ethano‐1,2,3,4‐tetrahydroisoquinolines as rigid analogs of adrenergic agents. Assignment of proton and carbon‐13 NMR parameters using homonuclear and heteronuclear two‐dimensional chemical shift correlation NMR spectroscopy
Authors: Muellner Frank W. , Abdel‐Sayed Ashraf N. , Bauer Ludwig
Published: April 2009

The synthesis of several rigid analogs of catecholamine type of adrenergic agents is reported. Their synthesis began with a Diels‐Alder cycloaddition of 4,5‐dibenzyloxybenzyne (generated from 4,5‐dibenzyloxyan‐thranilic acid) to 1‐(2‐trans‐phenylvinyl)‐2‐pyridone and 1‐benzyl‐3‐benzyloxy‐2‐pyridone. The unsaturated amides so produced were reduced first with hydrogen and palladium and then with lithium aluminum hydride to provide 6,7‐dihydroxy‐1,4‐ethano‐1,2,3,4‐tetrahydroisoquinolines. Homonuclear and heteronuclear two‐dimensional chemical shift correlation nmr spectroscopy confirmed the structure of the bridged tetra‐hydroisoquinolines and led to the unambiguous assignment of the 1H and 13C nmr chemical shifts of key compounds.
Synthesis of pyrrolo[2,1‐c][1,4]benzoxazepines. 1. A novel heterocyclic ring system
Authors: Effland Richard C. , Davis Larry
Published: April 2009

The synthesis of a novel pyrrolo[2,1‐c][1,4]benzoxazepine ring system (II) by a nucleophilic aromatic fluoride displacement‐cyclization is described. Aminoalkyl derivatives were prepared by either the Mannich reaction, or Vilsmeier formylation to provide the 3‐formyl derivative which was further elaborated.
α‐Halo sulfides in the alkylation of 2‐pyrimidinones
Authors: Strande Per , Benneche Tore , Undheim Kjell
Published: April 2009

When α‐halo sulfides are reacted with ambident 2‐pyrimidinones, the major product is due to N‐alkylation, the minor product to O‐alkylation. N‐Alkylation is favoured by the presence of a tertiary amine in a solvent of low dielectric constant and also by a change of the α‐halo sulfide substituent from chlorine to iodine. Complete selectivity can be achieved. The course of the reaction is rationalized in terms of the HSAB‐principle.
Non‐steroidal antiinflammatory agents. 3. Synthesis of 3‐hydroxy‐3‐hydroxyphenyl‐2,4‐dioxo‐1,2,3,4‐tetrahydroquinolines
Authors: Faber Kurt , Steininger Heinz , Kappe Thomas
Published: April 2009

The acid‐catalyzed condensation of quinisatines 5a‐c or their aminals 4a‐c with phenols 6a‐i led to a number of 3‐hydroxy‐3‐hydroxyphenyl‐2,4‐dioxo‐1,2,3,4‐tetrahydroquinolines 7a‐s which were considered as potential antiinflammatory agents.
Synthesis of 4‐thiocarbamoyl‐5‐aminopyrazoles
Authors: Giori P. , Veronese A. C. , Vicentini C. B. , Guarneri M.
Published: April 2009

Aryl and t‐butylhydrazines react with 2‐cyano‐3‐ethoxythiocrotonamide affording 2‐cyano‐3‐aryl‐t‐butylhy‐drazinothiocrotonamides. These intermediates can be easily cyclized to 4‐thiocarbamoyl‐5‐aminopyrazoles by heating a few minutes in a strong base. Alkylhydrazines react with 2‐cyano‐3‐ethoxythiocrotonamide yielding directly a mixture of the cyclized compounds 4‐cyano‐5‐aminopyrazoles and 4‐thiocarbamoyl‐5‐aminopyr‐azoles.
Configurations and conformations of some 3‐acetoxy‐cis‐hexahydro‐2(3H)‐benzofuranones
Authors: Dolmazon René , Gelin Suzanne
Published: April 2009

Catalytic hydrogenation of some 2‐ethoxalylcyclohexanones afforded a mixture of isomeric 3‐hydroxy‐cis‐hexahydro‐2(3H)‐benzofuranones. Three 5‐t‐butyl substituted diastereomers and two 5‐unsubstituted epimers were separated and identified as acetates. The configurations were determined by 350 MHz 1H‐nmr analysis. The conformations of these fused‐compounds are discussed.
A new heterocyclic system: Imidazo[2,1‐d][1,5]benzothiazepine. Its synthesis from 4‐amino‐2,3‐dihydro‐1,5‐benzothiazepine
Authors: Walia Jasjit S. , Walia Amrik S. , Lankin David C. , Petterson Robert C. , Singh Janak
Published: April 2009

The synthesis of 4‐amino‐2,3‐dihydro‐1,5‐benzothiazepine and its transformation to the new heterocycle Imidazo[2,1‐d][1,5]benzothiazepine is described.
Electron impact mass spectrometry of some cyclic tetraesters containing a tartaric moiety
Authors: Podda Gianni , Traldi Pietro
Published: April 2009

The mass spectrometric behaviour of some cyclic tetraesters containing tartaric moiety is described and discussed in detail with the aid of linked scans and exact mass measurements. The peculiar fragmentation patterns are emphasized.
Synthesis of novel 3‐substituted 1,5‐benzodiazepine derivatives
Authors: Kurasawa Yoshihisa , Shimabukuro Sayuri , Okamoto Yoshihisa , Ogura Kuniyoshi , Takada Atsushi
Published: April 2009

This paper describes an improved method for the synthesis of 3‐(3‐chloroquinoxalin‐2‐yl)‐1,2‐dihydro‐1‐formyl‐2‐oxo‐3H‐1,5‐benzodiazepine (2) and its conversions into novel 3‐substituted 1,5‐benzodiazepine derivatives (3a,b and 4a,b).
Synthesis of 4,9‐dimethoxy‐1H‐benz[f]indole
Authors: Malesani Giorgio , Ferlin Maria Grazia
Published: April 2009

A three‐step synthesis of 4,9‐dimethoxy‐1H‐benz[f]indole (4) starting from 1,4‐dimethoxy‐2‐aminonaphthalene (1) is described. Compound 1 was condensed with epichlorohydrin in acidic methanolic solution and the crude reaction product, purified by column chromatography, was cyclized to compound 3 by reflux heating in bromobenzene solution in the presence of excess diethylaniline. Appropriate oxidization with periodate in alkaline solution produced the title compound 4.
Studies on pyrazines. 12. N‐oxidation of aminopyrazines with m‐chloroperbenzoic acid
Authors: Sato Nobuhiro
Published: April 2009

N‐Oxidation reactions of 2‐aminopyrazines, substituted by methyl or phenyl groups at C‐3 or C‐5, with m‐chloroperbenzoic acid were undertaken to obtain the 2‐aminopyrazine 1‐oxides.
Synthesis of some 2,4‐disubstituted tetrahydropyrimido[4,5‐b]quinolines as potential antitumor agents
Authors: Gangjee Aleem , Ohemeng Kwasi A. , Tulachka Jacqueline J. , Lin Fu‐Tyan , Katoh Arthur A.
Published: April 2009

Cyclocondensations of two 2,4‐disubstituted 6‐aminopyrimidines with 2‐chloro‐1‐cyclohexenecarboxaldehyde afforded in each case a new regiospecific synthesis of tricyclic, linear disubstituted 6,7,8,9‐tetrahydro‐pyrimido[4,5‐b]quinolines 2 and 3 in excellent yields. The linear structures and hence the regiospecificity of the synthesis were established using 1H nmr and 13C nmr. The growth of leukemia L1210 cells in culture was inhibited 50% by 2 at 30 × 10−6M and 48% by 3 at 100 × 10−6M.
Synthesis of a substituted tetrahydropyrimido[4,5‐c][2,7]naphthyridine as a tricyclic 5‐deaza nonclassical folate
Authors: Gangjee Aleem , Ohemeng Kwasi A.
Published: April 2009

Condensation of 2,6‐diamino‐4‐hydroxypyrimidine with 1‐benzoyl‐1,2,3,6‐tetrahydropyrimidine‐5‐carboxal‐dehyde (4) afforded a mixture of angular and linear tricyclic tetrahydropyrimidonaphthyridines. Separation of the mixture was affected by fractional precipitation. Condensation of 2,4,6‐triaminopyrimidine with 1‐benzoyl‐4‐chloro‐1,2,3,6‐tetrahydropyridine (5) was regiospecific and afforded only the substituted angular tetra‐hydropyrimido[4,5‐c][2,7]naphthyridine (2). The vinyl aldehyde 4 and the chlorovinyl aldehyde 5 were prepared by modifications of literature procedures.
Mass spectrometry of 2,4‐substituted carcinogenic thiazoles and their metabolites
Authors: Mattammal Michael B. , Zenser Terry V. , Davis Bernard
Published: April 2009

The fragmentation pattern of some selected 2,4‐substituted carcinogenic thiazoles and their metabolites are described. Multiple modes of cleavages are seen when the 2‐amino group in thiazole is substituted.
The non‐intermediacy of benzo[1,2‐d:2,3‐d']bistriazole during the diazotization of a 4‐aminobenzotriazole
Authors: Oliver James E.
Published: April 2009

Labeling studies with 15N demonstrate that a diazonium ion prepared from a 4‐aminobenzotriazole does not cyclize to a tricyclic intermediate.
Novel synthesis of pyrazole and pyrazoline derivatives
Authors: Matsumura Noboru , Kunugihara Akira , Yoneda Shigeo
Published: April 2009

The 1,4‐dianion of acetophenone N‐ethoxycarbonylhydrazone reacts with carbonyl compounds such as esters, acyl chlorides, amides and α‐haloketones such as phenacyl chloride, 1‐chloroacetone, 1,3‐dichloroacetone, to produce pyrazole and pyrazoline derivatives in good yields, respectively.
Reaction of 1,3,4‐thiadiazolo and 1,3,4‐triazolo[3,2‐c]quinazoline derivatives with active methylene compounds
Authors: Molina P. , Arques A. , Cartagena I. , Valcarcel M. V.
Published: April 2009

Fused quinazoline derivatives 1 and 4 react with active methylene compounds and depending on the annelated five‐membered ring, two types of transformations have been observed. The 1,3,4‐thiadiazolo[3,2‐c]quinazoline 1, underwent the five‐membered ring opening reaction to afford the 3,4‐dihydroquinazolines 2 in good yields, whereas the 1,3,4‐triazolo[3,2‐c]quinazoline 4 underwent nucleophilic attack at 2‐position of the quinazoline ring to yield the corresponding 1,2,4‐triazoles 5.
3‐(4‐Hydroxyphenylthio)pyrrolidine‐2,5‐diones
Authors: Pastor Stephen D. , Hessell Edward T. , Odorisio Paul A. , Spivack John D.
Published: April 2009

3‐(4‐Hydroxyphenylthio)pyrrolidine‐2,5‐diones were prepared by the conjugate addition of substituted 4‐hydroxybenzenethiols to 1‐alkyl‐1H‐pyrrole‐2,5‐diones. The analytical and spectral data are reported.
Some heterocyclic sulfonyl derivatives
Authors: Cremlyn Richard J. , Swinbourne Frederick J. , Shode Olufemi
Published: April 2009

2,3‐Diphenylpyrazine, 3,4‐diphenylfurazan and 2‐methyl‐4,5‐diphenyl oxazole react with chlorosulfonic acid to give the sulfonyl chlorides Ia, IIa, IIIa. The chlorides were condensed with nucleophiles to give thirteen derivatives. 4′,4″‐bis‐Dimethylsulfamoyl‐2‐methyl‐4,5‐diphenyloxazole (Illb) was oxidized with bromine to give 4,4′‐bis‐dimethylsulfamoylbenzil (IV), which by heating with ethylenediamine afforded the 4′,4″‐bis‐dimethylsulfamoylpyrazine (V). The spectral data of the various compounds are briefly discussed.
Synthesis and spectral properties of 7‐(N‐arylsulfonyl)aminocoumarins, a new class of fluorescent pH indicators
Authors: Wolfbeis Otto S. , Baustert John H.
Published: April 2009

7‐Arylsulfonylamino‐coumarins 3 and 5, with electron‐delocalizing substituents in position 3 were obtained by condensation of 4‐arylsulfonylamino‐2‐hydroxybenzaldehyde with various (hetero)arylacetic esters and by other methods. Oxidative cyanation using potassium cyanide and elemental bromine gave the corresponding 4‐cyano derivatives 6a,b.

The absorption and emission maxima of coumarins 3 and 5 in organic solvents and in water of different pH were determined. All showed bright blue fluorescence in organic or acidic aqueous solution, which is shifted to the green in alkaline solution. The 4‐cyano derivatives 6a, b exhibit green fluorescences, which change to yellow in alkaline solution. Simultaneously the color changes from yellow to orange.

The pKa values of compounds 3 and 5 were found to lie between 6.33 and 7.06, whereas for the 4‐cyano derivatives they were distinctly lower (5.66‐5.95). The spectral changes observed in the near neutral pH range may render the new compounds useful indicators for the measurement of physiological pH's.
Synthesis of a new benzo[a]phenothiazine amino alcohol as a proposed antimalarial
Authors: Taunk Prakash C.
Published: April 2009

The synthesis of α‐(di‐n‐butylaminomethyl)‐2‐benzo[a]phenothiazinyl methanol hydrochloride is described. The ir and nmr spectra are also included.
Heteroyohimbane a noyau furannique. Nouvelle voie d'acces aux derives de la furo[3,2‐c]pyrone et de la furo[3,2‐c]pyridine
Authors: Mavoungou‐Gomès Louis , Bruneton Jean , Aicart Michel
Published: April 2009

Le dicarbométhoxy‐3,4 furanne porteur d'un groupement acétonyl ou phénacyl en position 2 est préparé par pyrolyse de l'adduit diénique semihydrogéné entre acétylènedicarboxylate de méthyle et acéeonyl‐2 ou phénacyl‐2 furanne. La condensation du composé acétonylé avec la tryptamine conduit aux dérivés d'un nouvel hétéroyohimbane à noyau furannique: l'indolo[2,3‐a]furo[3,2‐g]quinolizine, précurseur potentiel du yohimbane.

Les cétodiacides furanniques obtenus par saponification sont à la base d'une nouvelle voie d'accés aux deérivés de la furo[3,2‐c]pyrone‐4 et de la furo[3,2‐c]pyridine.
The stereochemistry of sulfonium ylides derived from 9‐alkylidenethioxanthenes– The relationship between ring inversion and S+C− bond rotation
Authors: Kluba M. , Harwood J. , Casey P. K. , Ternay A. L.
Published: April 2009

A series of sulfonium ylides has been prepared by the reaction of 9‐alkylidenethioxanthenes with dimethyl diazomalonate. The e' electron pair on sulfur is more efficient than the a' in trapping the “carbenes” generated by copper(II) catalyzed decomposition of diazo compounds. Consequently, e' ylides are the kineti‐cally‐controlled reaction products. Varying the C2 substituent does not alter this.

Sulfides and sulfonium ylides containing the isopropylidene moiety do not undergo rapid ring inversion. Rotation about the S+C− bond occurs in the pseudo‐axial conformation but not the pseudo‐equatorial. The use of the anisochronicity of portions of the malonylide fragment as a criterion for heterocyclic ring inversion is presented. It is suggested that the sulfoxides of phenothiazine, phenoxathiin, thianthrene, and related sulfoxides, undergo rapid ring inversion.
Reactions of 2‐aminooxazoles and 2‐aminothiazoles with dienophiles. Isolation of stable diels‐alder adducts
Authors: Crank George , Khan Humaid R.
Published: April 2009

Room temperature reaction of 2‐aminooxazole 1 and its 4‐ and 4,5‐substituted derivatives, with dimethyl acetylenedicarboxylate gave good yields of Diels‐Alder adducts 2, isolated as stable crystalline compounds. A competing process produced oxazole[3,2‐a]pyrimidines 3, also in good yield. Minor products were also identified. 2‐Amino‐4‐methylthiazole (6) reacted in a similar manner and gave the Diels‐Alder adduct 7 and a thia‐zolo[3,2‐a]pyrimidine 8 as main products with a lesser amount of a thiazole [3,2‐d][1:3]diazepine (9). The aminooxazoles reacted with olefinic dienophiles to give pyridine derivative, formed by breakdown of the original unstable adducts.
Synthesis and properties of 3‐nitrosocarbazole
Authors: Kyziol Janusz B.
Published: April 2009

The synthesis of 3‐nitrosocarbazole (I) by the Fischer‐Hepp rearrangement of 9‐nitrosocarbazole has been described. The resistance of I to oxidation provides evidence that it cannot be the intermediate in the conversion of 9‐nitrosocarbazole to the C‐nitro compounds. It has also been shown that I and its derivatives cannot be synthesized by the action nitrosyl chloride on carbazoles. Methylation of I yields 9‐methyl‐3‐nitrosocarbazole, 9,9′‐dimethyl‐3‐azocarbazole and 9,9′‐dimethyl‐3‐azoxycarbazole as the main products. The mechanism of this disproportionation process has been proposed. The spectral data of I are given.
Novel oxidation of tetrasubstituted furans by pyridinium chlorochromate
Authors: Akhtar Mohammed Shamim , Seth Manju , Bhaduri Amiya Prasad
Published: April 2009

A novel oxidation of tetrasubstituted furans with pyridinium chlorochromate has been studied and this has led to a convenient synthesis of 4‐acetoxy‐3‐acetyl‐ or methoxycarbonyl‐4‐substituted phenylbut‐3‐en‐2‐one.
Reaction products of 2‐aminobenzenethiol with some β‐diketones
Authors: Alyea Elmer C. , Malek Abdul
Published: April 2009

2‐Aminobenzenethiol undergoes condensation reactions with several β‐diketones (CH3, CF3 and C6H5 substituents) to form benzothiazolines. Conversion to benzothiazines and benzothiazoles occurs in some instances, as documented by the isolation and spectroscopic characterization of the products.
Nucleophilic substitution of 1,2,4‐triazines
Authors: Huang Jim J.
Published: April 2009

The reaction of 3‐(methylthio)‐5‐carbethoxy‐1,2,4‐triazine (5) with ammonia was found to yield products from not only ammonia but also methanethiolate displacements. An account of the transformations and the products observed is given. The 3‐position of 3,6‐bis(methylthio)‐5‐carbamoyl‐1,2,4‐triazine (7) was shown to be more reactive than the 6‐position toward nucleophilic substitution. Reduction at the 4,5 positions of triazine 5 occurred upon treatment with methanethiol under basic and neutral conditions.
Synthesis of 2‐substituted 3‐oxoisothiazolo[5,4‐b]pyridines
Authors: Monge A. , Martinez‐Merino V. , Fernandez‐Alvarez E.
Published: April 2009

Starting with 2‐chloro‐3‐pyridinecarboxylic acid 1, three different routes to prepare 3‐oxoisothiazolo‐[4,5‐b]pyridines 10 were studied.
Cyclocondensation of 2‐hydrazinoperimidine with diethyl oxalate and ethyl pyruvate
Authors: Liu Kang‐Chien , Chen Hsiu‐Ho
Published: April 2009

Refluxing 2‐hydrazinoperimidine (1) with excess amount of diethyl oxalate (2a) gave ethyl 1H‐1,2,4‐triazolo[4,3‐a]perimidine‐3‐carboxylate (4a) in 84% yield. On the other hand, heating 1 with ethyl pyruvate (2b) in glacial acetic acid afforded 3‐methyl‐1,2,4‐triazino[4,3‐a]perimidin‐4(1H)‐one (6b) in 92% yield. Structures of the products were investigated by spectral and elemental analysis.
Synthesis of selected 3‐substituted‐pyrimido[5,4‐e]1,2,4‐triazine‐5,7‐diamines as potential folate antagonists
Authors: Werbel Leslie M. , Elslager Edward F. , Johnson Judith L.
Published: April 2009

3‐(Anilinomethy1) 3‐[(arylthio)methy1]pyrimido[5,4‐e]‐1,2,4‐triazine‐5,7‐diamines were prepared by ring closure of 6‐hydrazino‐4‐[(phenylmethy1)thio]‐2.5‐pyrimidinediamine. these nonclassical analogs of known potent dihydrofolate reductase inhibitors were inactive against malarial infections in mice and L1210 leukemia in vitro.
Synthesis of N4‐(5‐methoxy‐7‐benzofuranyl)‐1,4‐pentanediamine, an oxygen isostere of primaquine
Authors: Johnson Judith L. , Werbel Leslie M.
Published: April 2009

N4‐(5‐Methoxy‐7‐benzofuranyl)‐1,4‐pentanediamine, an oxygen isostere of primaquine was synthesized and found devoid of antimalarial activity.
Synthesis of novel N‐(1,2,3,7,8,9,9a,9b‐octahydro‐3‐(phenylmethyl)‐5H‐dipyrrolo [1,2‐c,3,2‐e]pyrimidine‐5‐ylidene)benzenamine derivatives
Authors: Matthews Donald P.
Published: April 2009

N‐(1,2,3,7,8,9,9a,9b‐Octahydro‐3‐(phenylmethyl)‐5H‐dipyrrolo [1,2‐c,3,2‐e]pyrimidine‐5‐ylidene)benzenamine were prepared in moderate yields from the novel intermediate 1′‐(phenylmethyl)‐(2,3′‐bipyrrolidin)‐2‐one 4.
Chemistry of thienopyridines. XXXIV. Mass spectral fragmentation patterns of some secondary amines and related imines
Authors: Klemm L. H. , White D. V.
Published: April 2009

The mass spectra of some secondary amines and aldimines in the thieno[2,3‐b]pyridine (3) system are presented. α, α‐Bis(4‐thieno[2,3‐b]pyridylamino)toluene (1) undergoes (a) electron impact‐induced dissociation at 80° to give the spectrum of 4‐amino‐3 (3b) and (b) thermal dissociation at 200° to give a composite spectrum of 3b and its benzylidene derivative. Spectra of benzylamino and dimethylaminobenzylamino derivatives of 3 are dominated by benzyl‐type fragments, while benzylideneimino derivatives show more varied fragmentation.
A new ring opening reaction of N‐aminophthalimide hydrazones
Authors: Hearn Michael J. , Rosenberg Judith , Campbell Mary L.
Published: April 2009

Araldehyde hydrazones III of N‐aminophthalimide underwent rapid ring opening reactions initiated by the addition of excess base to their refluxing methanolic solutions. The products were conveniently isolated through liquid‐liquid extraction as the stable sodium salts V, and acidification precipitated the resulting phthalic acid congeners VI from aqueous solution. Compounds III readily exchanged one hydrazine moiety for another. For example, IIId reacted with 2,4‐dinitrophenylhydrazine to give the 2,4‐dinitrophenylhydrazone of 4‐chlorobenzaldehyde (VIId, 93%). Nonetheless, IIIg reacted exclusively at the carboxaldehyde function to give products VIIIa and VIIIb.
Hydrogenolysis of the CO bond of the 1,2,4‐oxadiazine ring. Adams platinum hydrogenation of 3‐aryl‐5,6‐dihydro‐5‐(substituted)‐methylene‐4H‐1,2,4‐oxadiazine derivatives
Authors: Kawashima Etsuko , Takada Toyozo , Tabei Katsumi , Kato Tetsuzo
Published: April 2009

Adams platinum hydrogenation of Z‐3‐aryl‐5,6‐dihydro‐5‐(substituted)methylene‐4H‐1,2,4‐ oxadiazine (1a‐f) proceeds very slowly through CO bond fission to give N‐(1‐substitutedcarbonyl‐2‐propylidene)benzamide ox‐ime derivative 2 as the main product. In the reaction of 5‐(arylcarbamoyl)methylene analogues 1d‐f, 5‐(aryl‐carbamoyl)methyl‐5,6‐dihydro‐3‐phenyl‐4H‐1,2,4‐oxadiazine (4) and N‐aryl‐3‐hydroxybutanamide derivative 5 are also obtained as well as compound 2.
Synthesis of 4,7‐dihydro‐4‐oxopyrrolo[2,3‐b]pyridine‐5‐carboxylic acid derivatives as potential antimicrobial agents
Authors: Vishwakarma Lal C. , Sowell J. Walter
Published: April 2009

Synthetic approaches to 1‐benzyl‐7‐alkyl‐2,3‐dimethyl‐4,7‐dihydro‐4‐oxopyrrolo[2,3‐b]pyridine‐5‐carboxylic acids from 1‐benzyl‐2‐amino‐3‐t‐butoxycarbonyl‐4,5‐dimethylpyrrole are reported.
Antidiabetische wirkstoffe. V Lang‐ und verzweigtkettig substituierte chlor‐dihexylamino‐1,3,5‐triazine
Authors: Kreutzberger Alfred , Rose Ulrich
Published: April 2009

Die nucleophile Substitution eines Chloratoms in 2,4‐Dichlor‐6‐dihexylamino‐1,3,5‐triazin (1) durch Amine (2a‐c) führt zu den Alkylamino‐chlor‐dihexylamino‐1,3,5‐triazinen 3a‐c. Für Strukturtyp 3 typische Signale in den 1H‐NMR‐Spektren sind das Triplett bei 0,9 ppm für die endständigen Methylgruppen und das Multiplett bei 3,3‐3,65 ppm für die den Stickstoffatomen benachbarten Methylengruppen. In Verbindungsklasse 3 finden sich Vertreter mit antidiabetischer, trichomonazider, antiviraler und anthelminthischer Wirksamkeit.
Synthesis of novel quinoxalines by ring transformation of 3‐quinoxalinyl‐l,5‐benzodiazepine
Authors: Kurasawa Yoshihisa , Shimabukuro Sayuri , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

Ring transformation of the 3‐quinoxalinyl‐l,5‐benzodiazepine (2) gave 3‐(benzimidazol‐2‐ylmethylene)‐2‐oxo‐l,2,3,4‐tetrahydroquinoxaline hydrochloride (4a), whose treatment with 5% sodium hydroxide provided the free base 5a, while refluxing of the 3′‐chloro‐l‐formyl derivative 3 in acetic acid and in 10% hydrochloric acid/acetic acid afforded 3‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)‐1,2‐dihydro‐1‐formyl‐2‐oxo‐3H‐1,5‐benzodiazepine hydrochloride (7) and 3‐methyl‐2‐oxo‐l,2‐dihydroquinoxaline (6), respectively. Compounds 4a and 5a were converted into 3‐(α‐hydroxyiminobenzimidazol‐2‐ylmethyl)‐2‐oxo‐l,2‐dihydroquinoxaline (8) and 3‐(benzimidazol‐2‐ylcarbonyl)‐2‐oxo‐l,2‐dihydroquinoxaline (10), respectively, which were further transformed into 3‐(benzimidazol‐2‐yl)isoxazolo[4,5‐b]quinoxaline (9) and 12‐(benzimidazol‐2‐yl)‐6H‐quinoxalino[2,3‐bI1,5]benzodiazepine (11), respectively.
Regioselective synthesis of pyrido[2,3‐d]pyrimidines
Authors: Anderson Gary L.
Published: April 2009

The reaction of diethyl ethoxymethylenemalonate (1) and 6‐amino‐1,3‐dimethyluracil (2) was determined to be regioselective. Under acidic conditions the product was the previously isolated 7‐oxopyrido[2,3‐d]pyrimidine (3), while in the presence of one equivalent of base followed by thermal cyclization, the isomeric 5‐oxopyrido[2,3‐d]pyrimidine (5) is formed.
Reaction of ketenes with N, N‐disubstituted α‐aminomethyleneketones. XVI. Synthesis of N, N‐disubstituted 4‐amino‐5,6‐tetramethylene‐3‐phenyl‐2‐pyranones
Authors: Bargagna Alberto , Schenone Pietro , Longobardi Mario
Published: April 2009

1,4‐Cycloaddition of phenylchloroketene (prepared in situ from α‐chlorophenylacetyl chloride and triethyl‐amine) to a number of N,N‐disubstituted (E)‐2‐aminomethylenecyclohexanones gave the corresponding adducts, namely N,N‐disubstituted 4‐amino‐3‐chloro‐3,4,5,6,7,8‐hexahydro‐2H‐1‐benzopyran‐2‐ones III in the case of aliphatic N,N‐disubstitution or aromatic N‐monosubstitution. Purification of III was possible only in the case of IIIh (NR2 = NMePh), therefore they were dehydrochlorinated in situ with DBN to give the title compounds in moderate overall yields.
Thermolysis of 7‐phenyl‐2,3,7‐triazabicyclo[3.3.0]oct‐2‐ene‐6,8‐dione
Authors: Majchrzak Michael W. , Kotelko Antoni
Published: April 2009

Thermolysis of the title compound in boiling xylene (138°) produces a 7.7/10.1/1.0 mixture of the N‐phenylimides of cis‐1,2‐cyclopropanedicarboxylic acid, citraconic acid, and itaconic acid. The imides of citraconic and itaconic acids are produced by hydrogen shifts. A completely concerted mechanism involving simultaneous hydrogen shift and cleavage of both C‐N bonds is unlikely in the present case because both hydrideshift products are formed and because the optimal arrangement for the hydrogen shift requires deformation of the imide ring and loss of imide resonance. The CN bond strengths in the title compound should be quite different. The products can arise either from two parallel pathways involving nitrogen‐containing dipoles or from a single nitrogen‐free trimethylene fragment.
Synthesis of 2‐thioxo‐3‐benzothiazolineacetonitrile and related products
Authors: D'Amico John J. , Suba Lydia , Ruminski Peter G.
Published: April 2009

Attempts to thermally rearrange 2‐benzothiazolylthioacetonitrile (1) to the titled compound 8 failed. The reaction of 3‐chloromethyl‐2‐benzothiazolinethione with potassium cyanide in dimethylformamide (DMF) or dimethylsulfoxide (DMSO) at 25‐30° afforded 8 in 98% yield. Whereas replacing the DMF or DMSO solvent with acetone furnished the unexpected sulfide 9 in 92% yield. Substituting 3‐chloromethyl‐2‐benzoxazoline‐thione as the electrophile in the same reaction gave the sulfide 10 in 95% yield. Possible mechanisms and supporting nmr data are discussed.
Synthesis of 5H‐pyrido[2,3‐a]phenoxazin‐5‐one and 5H‐pyrido[3,2‐a]phenoxazin‐5‐one derivatives
Authors: Nan'ya Seiko , Maekawa Eturô , Hayakawa Hitoshi , Kitaguchi Yukio , Ueno Yoshio
Published: April 2009

The 5H‐pyrido[2,3‐a]phenoxazin‐5‐one derivatives and 5H‐pyrido[3,2‐a]phenoxazin‐5‐one derivatives were prepared by the condensation of substituted 2‐aminophenols with 6,7‐dibromo‐5,8‐quinolinequinone followed by dehalogenation in the presence of sodium hydrosulfite dissolved in aqueous pyridine under a nitrogen atmosphere.
Ring transformation of 3‐hydroxy‐1,2,5‐ and ‐1,2,4‐thiadiazoles and ‐isothiazoles into isothiazole, thiazole and thiophene derivatives
Authors: Mataka Shuntaro , Takahashi Kazufumi , Tashiro Masashi
Published: April 2009

Ring transformation of 3‐hydroxy‐1,2,5‐thiadiazole (1), 3‐hydroxy‐1,2,4‐thiadiazole (14), and 3‐hydroxyiso‐thiazole (18) by the reaction with acetic anhydride in the presence of DBU afforded isothiazoles 2‐5 and 13, thiazoles 15 and 16 and thiophenes 21‐25, respectively. The reaction of 1 with propionic anhydride gave isothiazole 13. The formation pathway of the products is mentioned.
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. V. Synthesis of 5‐acyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarbonitriles and 1,2,5,6,7,8‐hexahydro‐2,5‐dioxo‐3‐quinolinecarboxamides
Authors: Mosti Luisa , Schenone Pietro , Menozzi Ciulia
Published: April 2009

The reaction of open‐chain sym‐2‐dimethylaminomethylene‐1,3‐diones Ia‐d with sodium cyanoacetamide gave, generally in good yields, 6‐substituted 5‐acyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarbonitriles IIa‐d, whereas cyclohexane sym‐2‐dimethylaminomethylene‐1,3‐diones Ie‐h afforded in general a mixture of 1,2,5,6,7,8‐hexahydro‐2,5‐dioxo‐3‐quinolinecarbonitriles and 5,6,7,8‐tetrahydro‐2,5‐dioxo‐2H‐1‐benzopyran‐3‐carboxamides, the latter being isolated in two cases. The reaction of Ie‐h with cyanoacetamide in refluxing anhydrous ethanol gave 1,2,5,6,7,8‐hexahydro‐2,5‐dioxo‐3‐quinolinecarboxamides IIIe‐h in excellent yields, whereas Ia‐d did not react with the exception of Ia which afforded in good yield 3‐pyridinecarboxamide IlIa. Other 3‐pyridine‐carboxamides were obtained by partial hydrolysis of nitriles IIb,d. 3‐Pyridine and 3‐quinoline carboxamides were hydrolyzed in satisfactory yields with hydrochloric acid to the corresponding carboxylic acids, which were decarboxylated in good yields to 5‐acyl‐2(1H)‐pyridinones and 7,8‐dihydro‐2,5(1H,6H)‐quinolinediones, respectively, by reflux in quinoline containing a catalytic amount of copper powder.
Synthesis of oxindole derivatives from N‐alkenyl‐o‐chloroanilides with zero‐valent nickel complex
Authors: Canoira L. , Rodriguez J. G.
Published: April 2009

Oxindole derivatives have been obtained from N‐alkenyl‐o‐chloroanilides by reaction with tetrakis(triphenylphosphine)nickel(0) in toluene as solvent in good yields. A detailed analysis of all the products of the reaction allows to confirm the postulated mechanism of the cyclization reaction. The o‐chloroanilides of the 3‐cyclohexenylacetic acid fails in the cyclization reaction, since the torsional hindrance seems to avoid that the endocyclic double bond may be orthogonally to the ortho‐σ‐nickel complex intermediate on the aromatic ring.
Lewis‐acid promoted aromatic cyclization of α‐chlorosulfides: Synthesis of ethyl isothiochroman‐1‐carboxylate and related compounds
Authors: Ishibashi Hiroyuki , Okada Motofumi , Iida Kyoko , Ikeda Masazumi
Published: April 2009

A variety of ethyl isothiochroman‐1‐carboxylates and related compounds were synthesized by treatment of 2‐chloro‐2‐[(2‐arenyl)ethylthio]acetates with stannic chloride in methylene chloride. The same procedure was applied to the synthesis of ethyl 4‐chloro‐4‐methyltetrahydrothiopyran‐2‐carboxylate. Some isothiochroman‐1‐carboxylic acids were prepared and evaluated for antiinflammatory activity. Among the compounds tested, 7‐phenoxyisothiochroman‐1‐carboxylic acid showed weak activity.
Mass spectral fragmentation pattern of 2,3‐dimethyl‐ and 2‐methyl‐3‐phenyl‐4‐arylazoisoxazol‐5‐ones
Authors: Keats Neil G. , Singh Shyam K. , Summers Lindsay A.
Published: April 2009

2,3‐Dimethyl‐4‐arylazoisoxazol‐5‐ones and 2‐methyl‐3‐phenyl‐4‐aryiazoisoxazol‐5‐ones undergo considerable fragmentation on electron impact. The base peaks in the mass spectra are at mass 56 and 118 respectively attributed to the N‐methylacetonitrile cation and the N‐methylbenzonitrile cation.
Brominated derivatives of 4‐hydroxy‐ and 4‐methoxy‐6‐methyl‐2H‐pyran‐2‐ones
Authors: De March P. , Moreno‐Mañas M. , Pi R. , Ripoll I. , Sánchez‐Ferrando F.
Published: April 2009

Twenty‐five different brominated derivatives of 4‐hydroxy‐6‐methyl‐2‐pyrone (triacetic acid lactone) and 3‐acetyl‐4‐hydroxy‐6‐methyl‐2‐pyrone (dehydroacetic acid) have been prepared. Fifteen derivatives have not been previously described and the preparations of a few known products have been improved. Bromination at C‐3, C‐5, methyl group at C‐6 and deacetylations at C‐3 have been the types of reactions used.
Pyridazines. XXV. Formation of 2‐benzoyl‐2,5‐dihydro‐3‐pyridazinecarbonitrile derivatives in the reissert reaction of pyridazines
Authors: Dostal Wolfgang , Heinisch Gottfried
Published: April 2009

Pyridazines 1a, b on treatment with potassium cyanide/benzoyl chloride in a mixed solvent system gave 2‐benzoyl‐2,5‐dihydro‐3‐pyridazinecarbonitriles 3a, b together with products resulting from attack of one mole of cyanide ion and three moles of benzoyl chloride (5a, b). The structures of these novel compounds are proved. A plausible reaction mechanism is proposed, involving rearrangement of initially formed 2a, b into 3a, b. Furthermore, the synthesis of the pyridazine Reissert compound 2a is reported.
Preparation of pyrrolo[3,2,1‐jk]carbazole by nickel(0) mediated ring contraction of pyrrolo[3,2,1‐kl]phenothiazine. Proton NMR and mass spectral studies
Authors: Klingstedt Tomas , Hallberg Anders , Dunbar Philip , Martin Arnold
Published: April 2009

Pyrrolo[3,2,1‐jk]carbazole 1a, the previously unreported 16π‐electron parent compound, has been synthesized by treatment of pyrrolo[3,2,1‐kl]phenothiazine 2a with a 1:1 mixture of bis(1,5‐cyclooctadiene) nickel(0) and 2,2′‐bipyridyl. An unequivocal assignment of the 1H nmr spectrum of 1a was made by decoupling experiments and by comparison with the 1H nmr spectrum of 1,9‐dideuteriopyrrolo[3,2,1‐jk]carbazole 1b. Metastable ion studies, exact mass measurements and the dideuterioderivative 1b were utilized to investigate the electron impact induced fragmentation of 1a.
Obtention d'hétérocycles par action de binucléophiles diazotés sur des chalcones: Influence du substituant en position 2
Authors: Simon Dominique , Lafont Olivier , Farnoux Claude Combet , Miocque Marcel
Published: April 2009

La réactivité de chalcones substituées en position 2 vis‐à‐vis de binucléophiles α.azotés (hydrazines, thiourée, guanidine) est mise à profit pour synthétiser des hétérocycles variés (pyrazoles, pyrazolines, pyrimidines), ainsi que des hydrazines substituées. Une interprétation générale est donnée, en fonction de la nature du substituant R du système énone, de la nature du binucléophile, et du milieu réactionnel.
Preparation of 1,8‐naphthalimides as candidate fluorescent probes of hypoxic cells
Authors: Middleton Richard W. , Parrick John
Published: April 2009

A number of nitro‐ and dinitro‐1,8‐naphthalimides have been prepared as potential fluorescent probes of hypoxic cells. The susceptibility of 4‐nitro‐1,8‐naphthalic anhydrides and ‐naphthalimides to nucleophilic displacement of the nitro group has been demonstrated by reaction with 1‐butanethiol to yield 4‐butylthio derivatives. Attempted nitration of these 4‐butylthio derivatives with sodium nitrate and concentrated sulphuric acid yielded the corresponding sulphoxides in high yield.
Reaction of benzoxazolone with 2,4‐dinitrochlorobenzene: Formation of 10‐(2,4‐dinitro)phenyl‐3‐nitrophenoxazine
Authors: Moreno‐Mañas M. , Sánchez‐Ferrando F. , Valle S.
Published: April 2009

Arylation of benzoxazolone 1 by 2,4‐dinitrochlorobenzene 2 under solid‐liquid phase transfer catalysis (PTC) gave 3‐(2,4‐dinitro)phenylbenzoxazolone 3 and 10‐(2,4‐dinitro)phenyl‐3‐nitrophenoxazine 4. Neither PTC nor copper catalysis achieved arylation of 1 by less activated aryl halides.
Hypervalent iodine oxidation. Synthesis of spin labeled, 1‐oxyl‐2,2,6,6‐tetramethylpiperidine derivatives
Authors: Moriarty Robert M. , Prakash Indra , Penmasta Raju
Published: April 2009

Oxidation of 1‐oxyl‐2,2,6,6‐tetramethyl‐4‐piperidone (1) with [I,I‐bis(acetoxy)iodo]benzene in methanolic potassium hydroxide yields 1‐oxyl‐4,4‐dimethoxy‐3‐hydroxy‐2,2,6,6‐tetramethylpiperidine (2). Treatment of 2,2,6,6‐tetramethyl‐4‐piperidone (3) with [I,I‐bis(acetoxy)iodo]benzene in methanolic potassium hydroxide gave 3‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidone (4) which on oxidation with 30% hydrogen peroxide and catalytic amount of sodium tungstate gave 1‐oxyl‐3‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidone (5). The esr spectra of 1‐oxyl‐4,4‐dimethoxy‐3‐hydroxy‐2,2,6,6‐tetramethylpiperidine (2) as well as 1‐oxyl‐3‐methoxy‐2,2,6,6‐tetramethyl‐4‐piperidone (5) show three lines.
1‐Azabenz[a]anthracene and 9‐azabenz[a]anthracene
Authors: Tanga Mary J. , Almquist Ronald G. , Smith Thomas H. , Wu Helen Y. , Reist Elmer J.
Published: April 2009

The synthesis of 1‐azabenz[a]anthracene and 9‐azabenz[a]anthracene are presented.
Arylidène‐5 méthyl‐6 4H pyridazines substitutées en 3 et systèmes a noyaux condenées
Authors: Taoufik J. , Couquelet J. M. , Couquelet J. D. , Tronche P.
Published: April 2009

En vue de prospecter les activités pharmacologiques des arylidène‐5 méthyl‐6 4H pyridazines, plusieurs series de derives substitues en position 3 ont été préparées au départ de pyridazinones 1 synthétisées au laboratoire. Les chloropyridazines 3 constituent des intermédiaires permettant d'accéder soit aux amino‐pyridazines 4, soit aux hydrazino‐pyridazines 5. Ces dernières peuvent à leur tour donner lieu à la formation de systèmes condensés tels que les triazolopyridazines 6 et les tétrazolopyridazines 7 ou encore de dérivés pyrazoliques 8 éventuellement fonctionnalisés. Les spectres de rmn 1H confirment la structure des différents composés obtenus.
(Perhalogenmethylthio)heterocyclen. XIX. Darstellung und eigenschaften von tetrakis(trifluoromethylthio)thiophen, tetrakis‐(trifluoromethylthio), ‐1,2‐dithiin, 2,3,4‐tris(trifluoromethylthio)‐5‐trifluor‐methylthiophen und 1‐chlor‐tetrakis(trifluormethylthio)pyrrol
Authors: Haas Alois , Klare Christiane , Krächter Hans‐udo
Published: April 2009

Bis(trifluormethyl(thio)acetylen reagiert mit Schwefel bei 170° zu Tetrakis(trifluormethylthio)thiophen, ‐1,2‐dithiin und 2,3,4‐Tris(trifluormethylthio)‐5‐trifluormethylthiophen. Mit Natriumhypochlorit setzt sich Tetrakis(trifluormethylthio)pyrrol in schwach alkalischer Lösung zu N‐Chlor‐tetrakis(trifluormethylthio)pyr‐rol um. Physikalische Daten der neuhergestellten Verbindungen werden angegeben.
3,6‐diisopropyl‐2‐hydroxypyrazine and 3,6‐diisopropyl‐2‐pyrazinethiol as carriers of some alkoxycarbonyl groups
Authors: Ohta Akihiro , Inagawa Yukiko , Mitsugi Chie
Published: April 2009

Some derivatives of benzyloxycarbonylated 3,6‐diisopropyl‐2‐hydroxypyrazine and 3,6‐diisopropyl‐2‐pyrazinethiol were prepared and shown to be the versatile benzyloxycarbonylation reagents for amines and amino acids. It was also ascertained that 3,6‐diisopropyl‐2‐hydroxypyrazine and 3,6‐diisopropyl‐2‐pyrazine‐thiol serve effectively as carriers of the β,β,β,‐trichloroethoxycarbonyl group.
On the synthesis of geometric isomers of 2‐methyl (or phenyl)‐4‐[α‐arylethylidene]‐5(4H)‐oxazolones
Authors: Cativiela C. , De Villegas M. D. Diaz , Meléndez E.
Published: April 2009

Several Z‐2‐methyl(or phenyl)‐4‐[α‐arylethylidene]‐5(4H)‐oxazolones 3Z, 4Z were prepared. The results obtained were compared by diazomethane insertion and condensation procedure. In order to synthesize E‐2‐phenyl‐4‐[α‐arylethylidene]‐5(4H)‐oxazolones 4E hydrogen bromide isomerization in dry benzene was used.
Synthesis of some 4‐acetyl‐3,5‐dioxo‐2,3,4,5‐tetrahydro[1]benzoxepine or benzothiepine and 6‐acetyl‐5,7‐dioxo‐6,7,8,9‐tetrahydro‐5H‐benzocycloheptene derivatives
Authors: Deshayes Christian , Chabannet Michel , Gelin Suzanne
Published: April 2009

The title compounds were prepared from benzoxepino‐, benzothiepino‐ or benzocycloheptaisoxazolones which in turn were synthetized from simple materials.
The synthesis of hydroxyphenylthiophenes
Authors: Baldwin Larry J. , Pakray Sudabeh , Castle Raymond N. , Lee Milton L.
Published: April 2009

The synthesis of the five isomeric methoxyphenylthiophenes is described. The methoxy compounds were hydrolyzed to yield the hydroxyphenylthiophenes.
On the mechanism of steroidal osazone formation. Synthesis of triazole
Authors: Catsoulacos Panayotis
Published: April 2009

Using a substrate steroidal α‐bromo, α‐hydroxy and α‐acetoxyketones, we studied the mechanism of osazone formation. A synthetic approach for the preparation of cholestano‐2′‐phenyl[2,3‐d]triazole is described.
Action of hydrogen peroxide on some 2‐aminooxazoles and imidazolin‐2‐ones. Isolation of hydroperoxyimidazolidin‐2‐ones
Authors: Ginanneschi M. , Chelli M. , Rapi G.
Published: April 2009

The reaction of some 2‐aminooxazoles and imidazolidin‐2‐ones with hydrogen peroxide afforded stable trans‐β‐hydroxyhydroperoxy‐ or dihydroperoxyimidazolidin‐2‐ones according to the reaction conditions. In the case of 3a‐hydroxy‐7a‐hydroperoxyoctahydro‐2H‐benzimidazolidin‐2‐one, the trans isomer is forbidden and cis adduct was isolated. A radical pathway to these hydroperoxides is proposed. From 2‐amino‐4‐methyloxazole and hydrogen peroxide 2‐amino‐2‐hydroxy‐4‐methyloxazolidin‐4‐yl peroxyacetate was also isolated.
1,1‐Disubstituted‐2,3,4,9‐tetrahydro‐1H‐pyrido[3,4‐b]indolecarboxylic acid esters and ketones. The base catalyzed transformation of 1‐(2′,3′,4′,9′‐tetrahydrospiro[cyclohexane‐1,1′‐[1H]pyrido[3,4‐b]indol]‐2‐yl)alkanones into 2‐(4,9‐dihydro‐3H‐pyrido[3,4‐b]indol‐1‐yl)‐1 ‐alkylcyclohexanols
Authors: Bobowski George , Shavel John
Published: April 2009

Condensation of 1H‐indole‐3‐ethanamines 1 with cyclic β‐keto esters 2 under azeotropic conditions followed by acid‐catalyzed ring closure of the resulting enamines 3 gave 2′,3′,4′,9′‐tetrahydrospiro[piperidine‐3,1′,‐[1H]pyrido[3,4‐b]indole] ‐4‐carboxylic acid alkyl esters 4. Condensation of 1 with 2‐acylcycloalkanones 8 gave two types of enamines, 10 and 11, respectively. Enamines 10 on treatment with acid gave 1‐(2′,3′,4′,9′‐tetrahydro‐3H‐pyrido[3,4‐b]indol‐1‐yl)‐1‐alkylcyclohexanols 17. Compounds 17 were further dehydrated to give cycloalkane derivatives 19.
A new method for the synthesis of novel 1‐aryl‐3‐quinoxalinyl‐1,2,4‐triazol‐5‐ones
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Hotehama Keizo , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

The reactions of 3‐methoxycarbonylmethylene‐2‐oxo‐1,2,3,4‐tetrahydroquinoxaline 1 with aryl diazonium salts gave 3‐(α‐aryldiazenylmethoxycarbonylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines 2a‐c, whose reactions with hydrazine hydrate afforded 3‐(α‐aryldiazenylhydrazinocarbonylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines 3a‐c. The reactions of 3a‐c with nitrous acid resulted in the Curtius rearrangement to provide the 1‐aryl‐3‐quinoxalinyl‐1,2,4‐triazol‐5‐ones 4a‐c.
An efficient synthesis of diethyl coumarin‐3‐phosphonates
Authors: Singh Rajendra K. , Rogers Michael D.
Published: April 2009

A general synthesis of a number of diethyl coumarin‐3‐phosphonates (3) has been achieved using titanium tetrachloride‐pyridine as the condensing agent.
Long chain heterocyclic dyes. Part Two. Surface active dyes
Authors: Barni Ermanno , Savarino Piero , Viscardi Guido , Pelizzetti Ezio
Published: April 2009

A series of heterocyclic cyanine dyes were prepared. Unsymmetrical dyes showed self‐micellizing properties due to the presence of two positive charges and of a long alkyl chain. Symmetrical dyes, containing three positive charges and not containing the hydrophobic chain, did not give rise to micelles. The physical properties of the dyes and their spectra were briefly discussed. Cationic (HTAB) and anionic (SDS) surfactants gave strong interactions with surface active dyes, leading to deaggregation and solvation phenomena.
Migratory aptitudes in pinacol rearrangement of vic‐dihydroxychlorins
Authors: Chang C. K. , Sotiriou Chariklia
Published: April 2009

When vic‐dihydroxychlorins undergo a pinacol‐pinacolone rearrangement, the migratory aptitudes of common porphyrin substituents follow the order: alkyl groups, propionate side chain, H > methyl group > acetate side chain. C‐Alkylchlorins can be made by extremely short syntheses utilizing such rearrangement.
Synthesis of indazole derivatives from a N,N‐disubstituted 2‐halobenzoic hydrazide. Crystal structure of 1,2‐pentamethylene‐5‐nitro‐1,2‐dihydro‐3H‐indazol‐3‐one
Authors: Arán V. J. , Stud M. , Foces‐Foces C. , Cano F. H. , Martínez‐Ripoll M.
Published: April 2009

Thermal cyclization of the N,N‐disubstituted 2‐chlorobenzoic hydrazide 1 yields the 1,2‐pentamethylene indazolone 5, which structure is confirmed by X‐ray crystallography. We suggest that the reaction proceeds through an N,N‐alkyl shift in an initially formed indazolinium salt 2. An intermediate 1‐(5‐chloropentyl)indazolol 4 has been isolated.
Synthesis of 5‐(β‐D‐ribofuranosyl)‐1,2,4‐oxadiazole‐3‐carboxamide
Authors: Hennen William J. , Robins Roland K.
Published: April 2009

The title compound was synthesized in three steps from ethoxycarbonylformamide oxime (5) and 3,4,6‐tri‐O‐acetyl‐2,5‐anhydroallonyl chloride (4b) in 62% overall yield. An acid catalyzed de‐esterification was required to prevent a facile base catalyzed elimination reaction.
Synthesis of 1,3,4‐oxadiazol‐2‐ones with aliphatic groups at N‐3
Authors: Huang Jamin , Bushey Dean F. , Graves Michael D. , Johnson Brenda F. , Singleton Dianne D.
Published: April 2009

A series of 3‐substituted‐5‐methoxy‐1,3,4‐oxadiazol‐2‐ones were prepared from aldehydes, ketones, phenylacetic acids, and 1,2‐ and 1,3‐diketones. Conditions for the formation of these oxadiazolones from the precursor N‐carbamoyl chlorides depended on the structure, and varied from spontaneous ring closure to those requiring bases. Variation in the N‐3 substituents sometimes produced mixtures of isomers which were separated and identified. These molecules were prepared in order to study the effect of the N‐3 substituent variation on the biological properties of oxadiazolones.