bluuebunny/crossref_metadata_2025 huggingface dataset:
The synthesis of 4‐substituted‐4H‐1,2,4‐triazole‐3‐thiols and 3‐methylthio‐4‐substituted‐4H,2,4‐triazoles
Authors: Lin Yang‐i , Petty S. R. , Lovell F. M. , Perkinson N. A. , Lang S. A.
Published: March 2009

The synthesis of 4‐substituted‐4H‐1,2,4‐triazole‐3‐thiols and 3‐methylthio‐4‐substituted‐4H‐1,2,4‐triazoles by the condensation of 4‐substituted‐3‐thiosemicarbazides with dimethylformamide dimethyl acetal or dimethylacetamide dimethyl acetal is described. A discussion of the mechanistic pathway is included.
Reaction of arylamidoximes with dimethyl acetylenedicarboxylate and diethyl chlorofumarate. Stereochemistry of the adducts and the derived 1,2,4‐oxadiazines
Authors: Guzmán Angel , Romero Susana , Urquiza E. M. Guadalupe , Muchowski Joseph M.
Published: March 2009

It was shown that the addition of benzamidoxime to dimethyl acetylenedicarboxylate was predominantly cis‐oid in methanol or acetonitrile solution and mainly trans‐oid when benzene was the solvent. The stereochemistry of the cis‐oid (4a) and trans‐oid (5) adducts was deduced by transformation into the oxadia‐zinones (7a and 8a) which, upon hydrolysis and subsequent reaction with acetic anhydride, gave the furo‐[2,3‐c]‐1,2,4‐oxadiazine (9) and the symmetrical anhydride (10), respectively.

The reaction of diethyl chlorofumarate with the sodium salt of benzamidoxime produced the oxadiazinone (8c).
Internal oxidation‐reduction of quinoxaline‐2‐ carboxaldehyde 1,4‐dioxide
Authors: Kluge Arthur F. , Maddox Michael L.
Published: March 2009

Reaction of carboxaldehyde 1 with acetone cyanohydrin gives carboxylic acid 2. Reaction of 1 with acetone cyanohydrin in methanol affords the methyl ester 3. The structural assignment for 2 is supported by 13C nmr data and by the decarboxylation of deuterated 2 to give 4b. The internal oxidation‐reduction upon going from 1 to 2 is explained in terms of a mechanism whereby 1 is converted into its cyanohydrin 5 and then to acyl cyanide 6. Acyl cyanide 6 then reacts with either water or methanol to give 2 or 3.
Sur une attaque inhabituelle de l'hetérocycle du benzofuranne, par action de chlorure de sulfuryle sur l'acétamido‐3 nitro‐2 benzofuranne
Authors: Royer RenÉ , Risse Simone , Demerseman Pierre
Published: March 2009

Au lieu d'effectuer la chloration escomptée, le chlorure de sulfuryle transforme l'acétainido‐3 nitro‐2 benzofuranne en acétylimino‐3 chloro‐2 nitro‐2 coumaranne. Lorsque la réaction est effectuée en présence d'un alcool, elle fournit en outre un acétamido‐3 alkoxy‐3 chloro‐2 nitro‐2 coumaranne.
Convenient total synthesis of (dl)‐quebrachamine
Authors: Giri Venkatachalam S. , Ali Esahak , Pakrashi Satyesh C.
Published: March 2009

Racemic quebrachamine (1) has been synthesised from 2‐hydroxytryptamine and dimethyl 4‐ethyl‐4‐formylpimelate through 1,2‐dehydroaspidospermidine (8), obtained by selective reduction of the carbonyl function of lactam 3.
The reaction of β‐amino conjugated enones with trimethylchlorosilane
Authors: Kashima Choji , Yamamoto Yasuhiro
Published: March 2009

By the reaction of β‐amino conjugated enones with trimethylchloroailane, both amino acetophenone and pyridine derivatives were formed in good yield. The selectivity of the formation of the products depended on the bulkiness of the N‐substituents of β‐amino conjugated enones.
Sur la synthèse de quelques furochromènes, analogues pharmacochimiques de la xanthylétine et de la séseline
Authors: René Loïc , Faulques Michelle , Royer RenÉ
Published: March 2009

Some furochromenes substituted at the 2‐position by an electron‐attracting group were obtained starting from ortho‐hydroxyformyl derivatives of 2,2‐dimethyl‐2H‐chromene following various processes which are indicated. These new furochromenes are pharmacochemical analogues of some natural pyranocoumarins, and as such they are potential photosensitizers.
Novel heterocycles. 5. Lactone fused quinazolines
Authors: Coppola Gary M. , Shapiro Michael J.
Published: March 2009

Quinazoline fused lactones were synthesized. The six‐membered lactone 7 was prepared by the interaction of ethyl pyruvate with hydroxyethylanthranilamide 11, followed by hydrolysis and cyclization using 1‐methyl‐2‐choropyridinium iodide. The corresponding seven‐membered lactone 10 was prepared by reaction of 11 with ethyl propiolate, followed by hydrolysis and cyclization as above. Quinazolines possessing functionalities capable of forming either a six‐ or seven‐membered lactone were cyclized in xylene in the presence of sodium methoxide. Only the six‐membered lactone 14 formed.
Hydrazines et hydrazones heterocycliques. III. Synthese de derives du naphto[2,3‐d]thiazole
Authors: Leymarie‐Beljean Martine , Pays Michel , Richer Jean‐Claude
Published: March 2009

On rapporte la sythèse de l'hydrazino‐2 naphto[2,3‐d]thiazole, de l'hydrazone de la méthyl‐3 naptho[2,3‐d]‐thiazoline‐2 et de quelques (alkylidènehydrazino)‐2 méthyl‐3 naphto[2,3‐d]thiazoles correspondants. Les composés sont caractérisés par leurs spectres infrarouges, ultraviolets, rmn en présence d'Eu(fod)3 et de masse.
Reissert compound studies. XXXVI. Observations on 1,7‐, 4,6‐, 4,7‐, and 1,10‐phenanthrolines
Authors: Bhattacharjee D. , Popp F. D.
Published: March 2009

Reissert compounds have been prepared from 1,7‐, 4,6‐, and 4,7‐phenanthrolines. In the case of 4,7‐phenanthroline, both mono‐ and di‐Reissert compounds have been prepared. A number of Reissert analogs have also been prepared in this series. 1,10‐Phenanthroline fails to give a Reissert compound.
Enamines. 41. A new synthesis of α‐amino‐pyrroles
Authors: Baroni Sergio , Stradi Riccardo , Saccarello Maria Luisa
Published: March 2009

Diimmonium salt 1 reacts with enamines 3 affording α‐amino‐pyrroles 4. The synthetic potential of this reaction is discussed.
2‐Amino‐4‐aryl‐6‐(ω‐carboxyalkyl)‐5H‐pyrrolo[3,4‐d]pyrimidin‐7‐(6H)ones. Preparationviaa one‐pot synthesis of 1‐(ω‐carboxyalkyl)‐4‐carbethoxy‐2,3‐dioxopyrrolidines
Authors: Madhav R. , Snyder Carroll A. , Southwick Philip L.
Published: March 2009

1‐(ω‐Carboxyalkyl)‐4‐carboethoxy‐2,3‐dioxopyrrolidines were prepared by a one‐pot synthesis from β‐alanine or γ‐aminobutyric acid, ethyl acrylate and diethyl oxalate. In a second one‐pot process these products were hydrolyzed, decarboxylated and condensed with aromatic aldehydes under the influence of hydrochloric acid to yield 1‐(ω‐carboxyalkyl)‐4‐arylidene‐2,3‐dioxo‐pyrolidines, which yielded 2‐amino‐4‐aryl‐6‐(ω‐carboxyalkyl)‐5H‐pyrrolo[3,4‐d]pyrimidin‐7‐(6H)‐ones upon treatment with guanidine. It was shown that 3,4‐dihydro derivatives of certain 2‐amino‐4‐aryl‐5H‐pyrrolo[3,4‐d]pyrimidin‐7‐(6H)ones, formed initially in the guanidine reaction, readily undergo conversion to 5H‐pyrrolo[3,4‐d]pyrimidin‐7‐(6H)ones.
The thermolysis of heterocyclic aminimines
Authors: Posvic Harvey , De Meireles Jorge C.
Published: March 2009

Aminimines derived from six heterocyclic tertiary amines were thermolyzed in t‐butyl alcohol at ca. 80°. N‐Methylindoline gave a good yield of the ring‐opened product, and a double elimination on 1,4,4‐trimethyl‐piperidine gave 3,3‐dimethyl‐1,4‐pentadiene. The aminimine derived from quinuclidine was stable to elimination under these conditions. Simple elimination products were not obtained from N‐methyl‐pyrrolidine, N‐methylpiperidine, or N‐methyltetrahydroisoquinoline.
Selenium‐sulfur analogs 2. Synthesis and characterization of 4‐aralkyl‐1,2,3‐selenadiazoles and ‐1,2,3‐thiadiazoles
Authors: Hanson Robert N. , Davis Michael A.
Published: March 2009

1 The3‐diketones 5 and 8 were alkylated with methyl iodide to give the nonenolizable diketones 6 and 9 which condensed with semicarbazide hydrochloride yielding the monosemicarbazones 7 and 10. Cyclization with selenous acid or with thionyl chloride led to the corresponding 1,2,3‐selenadiazoles 3a, 4a, and 1,2,3‐thiadiazoles 3b, 4b.
Synthesis of phenanthro[b]thiophenes
Authors: Iwao Masatomo , Lee Milton L. , Castle Raymond N.
Published: March 2009

All isomers of the parent phenanthro[b]thiophenes, namely, phenanthro[1,2‐b]thiophene, phenanthro‐[2,1‐b]thiophene, phenanthro[2,3‐b]thiophene, phenanthro[3,4‐b]thiophene, phenanthro[3,4‐b]thiophene, phenanthro[4,3‐b]thiophene and phenanthro[9,10‐b]thiophene have been synthesized.
Diazapolycyclic compounds. XX. Stereochemistry of some addition reactions to the double bond at the terminal tetrahydropyridazine ring of methyl substituted 4a,12a‐diaza‐1,4,4a,5,12,12a‐ and 4a,12a‐diaza‐3,4,4a,5,12,12a‐hexahydronaphthacene‐5,12‐diones, and the corresponding epoxides
Authors: Cano M. C. , Contreras F. Gómez , Sanz A. M.
Published: March 2009

The stereochemistry of N‐bromosuccinimide electrophilic additions to the double bond at the terminal tetrahydropyridazine ring moiety of the 4a,12a‐diazatetracyclic compounds 1‐4 has been studied. These reactions appear as very regio‐ and stereoselective. Most the of the results obtained support the hypothesis that the N‐bromoamide additions to cyclohexenes and heterocyclic analogous do not occur via the usual AdE2 mechanism, because the nucleophilic step is the rate‐limiting one and the main product‐determining factor. On the other hand, epoxidation of the double bond in 1‐4 and further opening of the oxirane ring take place in accordance with the normal stereochemical rules.
3‐Oxo‐1,2‐benzoisothiazoline‐2‐acetic acid 1,1‐dioxide derivatives. I. Reaction of esters with alkoxides
Authors: Schapira Celia B. , Perillo Isabel A. , Lamdan Samuel
Published: March 2009

Reaction of 3‐oxo‐1,2‐benzoisothiazoline‐2‐acetic acid alkyl esters 1,1‐dioxide (1a‐d) with alkaline alkoxides was carried out under various conditions. Under mild conditions, o‐(N‐carboxymethylsulfamyl)benzoic acids dialkyl esters (2a‐d) were obtained with good yields. Reaction of 1a‐d or 2a‐d with sodium alkoxides under drastic conditions afforded 4‐hydroxy‐2H‐1,2‐benzothiazine‐3‐carboxylic acid alkyl esters 1,1‐dioxide (3a‐d). Transesterification was observed when esters 1b‐d were treated with sodium methoxide in methanol. Esters 3a‐d were hydrolyzed in concentrated aqueous sodium hydroxide affording the acid 6. Attempts to recrystallize 6 from water resulted in its decarboxylation to give 2H‐1,2‐benzothiazine‐4‐(3H)one 1,1‐dioxide (7). Compound 6 could not be obtained by acid hydrolysis of esters 3a‐d or by rearrangement of 3‐oxo‐1,2‐benzoisothiazoline‐2‐acetic acid 1,1‐dioxide (8). Different experimental evidence supports the suggestion that rearrangement took place by ethanolysis of the carboxamide linkage affording the open sulfonamides (fast step) followed by a Dieckmann cyclization (slow step). It was demonstrated that transesterification took place in the open sulfonamides 2.
Versatile and efficient synthesis of aryl‐1,2,3,4‐tetrahydroisoquinolines: Nickel(II) phosphine ligand catalyzed coupling of arylmagnesium halides to haloisoquinolines
Authors: Pridgen Lendon N.
Published: March 2009

Dichloro[1,3‐bis(diphenylphosphino)propane]nickel(II) (dppp) was used as catalyst to prepare some previously unreported arylisoquinolines 3, which were in turn hydrogenated to aryl‐1,2,3,4‐tetrahydroiso‐quinolines 2. This procedure is the most direct and efficient method currently available for the preparation of many compounds of the type 2 and 3.
Synthesis of 1,8‐ and 2,8‐dihydrocycloheptapyrazol‐8‐one derivatives by the reactions of 3‐acetyltropolone and its methyl ethers with phenylhydrazine
Authors: Imafuku Kimiaki , Yamane Akio , Matsumura Hisashi
Published: March 2009

3‐Acetyltropolone (1) reacted with phenylhydrazine to give 3‐acetyltropolone phenylhydrazone (3) and 3‐methyl‐1‐phenyl‐1,8‐dihydrocycloheptapyrazol‐8‐one (4). The former (3) cyclized to afford the latter (4). The reaction of 3‐acetyl‐2‐methoxytropone (2a) with phenylhydrazine gave 4, 3‐methyl‐2‐phenyl‐2,8‐dihydrocyclo‐heptapyrazol‐8‐one (5), and 3‐methyl‐2‐phenyl‐2,8‐dihydrocycloheptapyrazol‐8‐one phenylhydrazone (6). The compound (5) reacted with phenylhydrazine to afford 6. The reaction of 7‐acetyl‐2‐methoxytropone (2b) with phenylhydrazone gave 7‐acetyl‐2‐methoxytropone phenylhydrazone (7), 7‐acetyl‐2‐(N′‐phenylhydrazino)‐tropone phenylhydrazone (8), 3‐methyl‐1‐phenyl‐1,8‐dihydrocycloheptapyrazol‐8‐one phenylhydrazone (9), and 6. The compound (7) was heated to afford 4 and reacted with phenylhydrazine to afford 8 and 9. The compound (8) was also refluxed to give 9.
A short efficient synthesis of 4‐amino‐2,3‐dihydrobenzofuran
Authors: Marburg S. , Tolman R. L.
Published: March 2009

A new, practical synthesis of 4‐amino‐2,3‐dihydrobenzofuran is described. Chlorination and a Sandmeyer reaction of the title compound are also reported.
Synthesis of 2‐substituted styryl‐6‐bromo‐4‐quinazolone 3‐(4‐benzhydrazides) as possible monoamine oxidase inhibitors
Authors: Misra R. S. , Dwivedi C. , Parmar S. S.
Published: March 2009

Nine ethyl 2‐substituted styryl‐6‐bromo‐4‐oxoquinazoline‐3‐(4‐benzoates) were prepared by condensing bromoacetanthranil with ethyl‐4‐aminobenzoates. These esters were converted to the corresponding hydrazides with hydrazine hydrate in order to study their monoamine oxidase inhibitory and anticonvulsant properties.
The synthesis of 3H‐pyrazol‐3‐one derivatives containing a 9H‐xanthene ring
Authors: Okabayashi Ichizo
Published: March 2009

2,4‐Dihydro‐5‐methyl‐2‐phenyl‐4‐(9H‐xanthen‐9‐yl)‐3H‐pyrazol‐3‐one (3) was prepared by the condensation of phenylhydrazine and ethyl α‐acetyl‐9H‐xanthene‐9‐acetate (2), or 9H‐xanthen‐9‐ol (1) and 2,4‐dihydro‐5‐methyl‐2‐phenyl‐3H‐pyrazol‐3‐one (4). 5‐Amino‐2,4‐dihydro‐2‐phenyl‐4‐(9H‐xanthen‐9‐yl)‐3H‐pyrazol‐3‐one (6) was obtained by the condensation of 1 and 5‐amino‐2,4‐dihydro‐2‐phenyl‐3H‐pyrazol‐3‐one (5).
Mannich's arsindole (1,3‐dichloro‐2‐diethylaminomethylbenzo[b]arsole hydrochloride). Ultraviolet spectrum and behaviour on electron impact. A comparison with other heterocyclic and acyclic chloroarsines
Authors: Allen David W.
Published: March 2009

The ultraviolet and mass spectra of the title compound have been recorded and compared with those of 2‐chloro‐2‐phenylvinyldichloroarsine (and other chloroarsines). The spectra of the arsindole resemble those of related indoles, phosphindoles and other aromatic heterocyclic systems, and are markedly different from those of the above acyclic chloroarsine, indicating the probable involvement of arsenic in a cyclic π‐delocalised system.
Synthesis and photopinacol rearrangement of 1a,9a‐dihydro‐1a,9b‐diphenylphenanthro[9,10‐b]oxirene
Authors: Avnir Davis , Blum Jochanan
Published: March 2009

The synthesis of the title compound is described. Pinacol reduction of 2,2′‐dibenzoylbiphenyl followed by dehydration of the trans‐diol, so formed, with dimethylformamide dimethyl acetal yielded 55% of the oxirane. Irradiation of the oxide in methylene chloride at 254 nm gave 10,10‐diphenyl‐9‐(10H)phenanthrone as the major photoproduct.
The first examples of the 11H‐[2]benzazepino[1,2‐a]dibenz[b,f]azocine ring system
Authors: Schwan Thomas J.
Published: March 2009

The ring closure of 2‐[(11,12‐dihydro‐6‐oxodibenz[b,f]azocin‐5‐yl)methyl]benzoic acid in polyphosphoric acid to 16,17‐dihydro‐11H‐[2]benzazepino[1,2‐a] dibenz[b,f]azocine‐4‐(9H)‐11‐dione is reported. Degradation studies supporting this structural assignment for the annelation product are described.
Thiophene systems. 4. Selective syntheses of thieno[3,4‐b][1,4]‐ and [1,5]benzodiazepinones
Authors: Press Jeffery B. , Hofmann Corris M. , Safir Sidney R.
Published: March 2009

Novel syntheses of thiophene fused tricyclic systems 1 and 2 are reported. The methods use intermediates 4‐ethoxy‐3‐thiopheneamine, 4‐ethoxy‐3‐thiophenecarbonyl aside and 4‐ethoxy‐3‐thiophenecarbonyl chloride to effect selective, high yield syntheses of the target compounds in two steps. These methods allow preparation of thiophene systems without substitution at the normally reactive C‐1 and C‐3 positions.
Action des dihydro‐4,5 oxazoles‐1,3 sur le dioxy‐2,2 oxathiolane‐1,2 I. Synthèse et caractérisations du (méthyl‐2 oxazolinium‐1,3)‐3 propanesulfonate
Authors: Forestière A. , Sillion B.
Published: March 2009

L'addition de la méthyl‐2 oxaxoline‐1,3 (1a) sur la propanesultone‐1 (3) (2) conduit à un composé ionique de type sulfobétaïne 4a que nous avons caractérisé par spectroscopie. La structure proposées est confirmée par quelques réactions chimiques de ce composé.
Syntheses with nitriles. 60. Preparation of 4‐amino‐5‐cyano‐6‐phenylpyrimidines from 2‐amino‐1,1‐dicyano‐2‐phenylethene
Authors: Mittelbach Martin , Junek Hans
Published: March 2009

The reaction of 2‐amino‐1,1‐dicyanobut‐1‐ene and 2‐amino‐1,1‐dicyano‐2‐phenylethene, respectively, with N,N‐dimethylformamide dimethylacetal provided the corresponding (N,N‐dimethylaminomethylene)amino derivatives. 2‐[(N,N‐Dimethylaminomethylene)amino]‐1,1‐dicyano‐2‐phenylethene was converted into 4‐amino‐5‐cyano‐6‐phenylpyrimidines by treatment with primary aliphatic and aromatic amines. The structure of the reaction products was confirmed by 13C nmr spectroscopy.
[1]Benzothienopyrimidines. II. Study of the electrophilic substitutions of [1]benzothieno[3,2‐d]pyrimidine and [1]benzothieno[3,2‐d]pyrimidin‐4‐(3H)one
Authors: Rault Sylvain , De Sévricourt Michel Cugnon , Touzot Paulette , Robba Max , El‐Kashef Hussein
Published: March 2009

The nitration and bromination of both [1]benzothieno[3,2‐d]pyrimidin‐4(3H)one (1) and [1]benzothieno‐[3,2‐d]pyrimidine (2) has been studied. Nitration of 1 at −30° afforded a mixture of 8‐nitro[1]benzothieno‐[3,2‐d]pyrimidin‐4(3H)one (7b) (70%) and 6‐nitro[1]benzothieno[3,2‐d]pyrimidin‐4(3H)one (7a) (30%). However when the nitration was carried out at 60°, the 6,8‐dinitro derivative 8 was the result. On the contrary, the nitration of 2 at −30° gave a single nitration product, 8‐nitro[1]benzothieno[3,2‐d]pyrimidine (11). The bromination of both 1 and 2 gave the corresponding 8‐bromo derivatives 10 and 13. Assignment of structure of all the products was based on ir and nmr spectral studies and on unequivocal syntheses.
Synthesis of 2,3‐dihydro‐1H‐imidazo[1,2‐b]pyrazoles
Authors: Pilgram Kurt
Published: March 2009

Two novel 2,3‐dihydro‐1H‐imidazo[1,2‐b]pyrazole derivatives 7 and 8 have been prepared by hydrazinolysis with 2,4‐dinitrophenylhydrazine of 1‐(benzylideneamino)‐2‐(2‐ethoxycarbonyl‐2‐nitromethylidene)‐imidazolidine 4. The precursor 4 was conveniently prepared from ethyl nitroacetate and 1‐(benzylidene‐amino)‐2‐(methylthio)imidazoline 3. Two examples are presented in which ethyl aceto(and trifluoroaceto)acetate 2‐nitrophenyl‐hyrazone, 9 and 10, both of which also feature the β‐hydrazinoacrylate arrangement, are refluxed in ethanol containing hydrochloric acid and thereby converted into pyrazolones 11 and 12, pyrazoles 13 and 14, and ketone 2‐nitrophenylhydrazones 15 and 16, respectively.
Mass spectra of azabicyclospirohydantoins
Authors: Trigo G. G. , Ballesteros P. , Espada M. , Santos E. , Gálvez E. , Avendaño C. , Martínez M.
Published: March 2009

The mass spectra of some N‐substituted nortropane and granataninespirohydantoins are compared with those of N‐substituted 3‐azabicyclo[3.2.1]octane‐8‐spiro‐, 3‐azabicyclo[3.3.1]nonane‐9‐spiro‐, 8‐azabicyclo‐[4.3.1]decane‐10‐spiro‐ and 3,7‐diazabicyclo[3.3.1]nonane‐9‐spiro‐5′‐hydantoins. Mass spectra data of monothio‐ and dithio‐tropanespirohydantoins are also included. Mass fragmentation and structure relationships of these molecules have been established.
Nucleosides. 117. Synthesis of 4‐oxo‐8‐(β‐D‐ribofuranosyl)‐3H‐pyrazolo[1,5‐a]‐1,3,5‐triazine (OPTR) via 3‐amino‐2N‐carbamoyl‐4‐(β‐D‐ribofuranosyl)pyrazole (ACPR) derivatives
Authors: Chu C. K. , Watanabe K. A. , Fox J. J.
Published: March 2009

Reaction of 2‐formyl‐2‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)acetonitrile (VII) with semicarbazide hydrochloride followed by sodium ethoxide treatment afforded an α,β‐mixture of 3‐amino‐2N‐carbamoyl‐4‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)pyrazole (IX). Conversion of IX to 4‐oxo‐8‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)‐3H‐pyrazolo[1,5‐a]‐1,3,5‐triazine (XIII) was achieved by treatment of IX with ethylorthoformate. The β‐isomer IXb gave only the β‐isomer XIIIb, and the α‐isomer IXa was converted exclusively into the α‐isomer XIIIa. Upon deprotection with 3% n‐butanolic hydrogen chloride, both IXa and IXb gave the same mixture of the α‐ and β‐isomers of 3‐amino‐2N‐carbamoyl‐4‐(D‐ribosyl)pyrazole, which were separated by chromatography.

The syntheses of the hitherto unknown compounds, 3‐amino‐2N‐carbamoylpyrazole (IVa) and its 4‐methyl analog (IVb) are also reported. Experimental details of the synthesis of 3‐amino‐4‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐β‐D‐ribofuranosyl)pyrazole (XIIb), an important intermediate for “purine‐like” C‐nucleosides, are also described.
The mechanism of the bischler‐napieralski reaction
Authors: Nagubandi Sreeramulu , Fodor G.
Published: March 2009

The Bischler‐Napieralski dihydroisoquinoline synthesis was proven to occur via imidoyl chlorides and the corresponding nitrilium salt. The two‐step process required much milder conditions (20°–50°) compared to drastic classical conditions of refluxing at 100°–200°. The Bischler‐Napieralski reaction is shown to share a common intermediate with two other well‐known reactions: the von Braun and the Ritter reactions.
Methylation of 2‐acylamido‐1,3,4‐thiadiazoles. An infrared, proton and carbon Nmr study
Authors: Leppard D. , Sauter H.
Published: March 2009

The site of methylation in 2‐acylamido‐1,3,4‐thiadiazoles can be determined by ir and Carbon‐13 nmr spectroscopy.
Stable nitroxide radicals. Reaction between 2‐cyano‐ and 4‐cyanobenzoquinoline N‐oxides and the grignard reagent
Authors: Colonna Martino , Greci Lucedio , Poloni Marino
Published: March 2009

2,2‐Diphenylbenzoquinolinenitroxide radicals were obtained starting from 2‐phenyl‐, 2‐cyano, 4‐cyano‐benzoquinoline N‐oxides, or from unsubstituted benzoquinoline N‐oxides with phenylmagnesium bromide. The elimination of bromomagnesium hydride from the 2‐unsubstituted benzoquinoline N‐oxides and cyanomagnesium bromide from the 2‐ or 4‐cyanobenzoquinoline N‐oxides is discussed.
Quino[1,2‐c]quinazolines. I. Synthesis of quino[1,2‐c]quinazolinium derivatives and the related indazolo[2,3‐a]quinoline derivatives as analogs of the antitumor benzo[c]phenanthridine alkaloids
Authors: Phillips Steven D. , Castle Raymond N.
Published: March 2009

9,10‐Dimethoxy‐1,2,3,4,12,13‐hexahydro‐1‐oxoquino[1,2‐c]quinazolinium perchlorate, 1,2,3,4,13,24‐hexahydro‐1‐oxo[1,3]dioxolo[4,5‐g]quino[1,2‐c]quinazolinium perchlorate, 6‐methyl‐2,3,9,10‐tetramethoxyquino‐[1,2‐c]quinazolinium perchlorate and 2,3‐dimethoxy‐13‐methyl[1,3]dioxolo[4′,5′:6,7]quino[1,2‐c]quinazolinium perchlorate were synthesized as analogs of the potent antitumor benzo[c]phenanthridine alkaloids nitidine and fagaronine. The related 2,3,8,9‐tetramethoxyindazolo[2,3‐a]quinoline and 2,3‐dimethoxy[1,3]dioxolo‐[4,5‐g]indazolo[2,3‐a]quinoline were also synthesized. Further, the novel formation of 6,7‐dimethoxy‐2‐(2‐ethylamino‐4,5‐dimethoxyphenyl)quinoline via reductive alkylation with Raney nickel in refluxing ethanol is also reported.
Entzündungshemmende wirkstoffe. VIII 5‐ und 6‐chlorierte 1‐aroylbenzotriazole
Authors: Kreutzberger Alfred , Stratmann JÖRg
Published: March 2009

Die Umsetzung von 5‐Chlorbenzotriazol (1) mit den entsprechenden Carbonsäurechloriden (2) führt einerseits zu den (3,5‐Dinitrobenzoyl)‐ (3a), (4‐Fluorbenzoyl)‐ (3b) und (4‐Chlorbenzoyl)‐Derivaten (3c) des 5‐Chlorbenzotriazols, andererseits zu den (4‐Nitrobenzoyl)‐ (4a), (3,4,5‐Trimethoxybenzoyl)‐ (4b), (4‐Methoxybenzoyl)‐ (4c), Crotonyl‐ (4d), Cinnamoyl‐ (4e) und Pentafluorbenzoyl‐Derivaten (4f) des 6‐Chlorbenzotriazols. Insbesondere vermag 4e einen auffallenden entzündungshemmenden Effekt auszulösen.
Reactions of α,β‐unsaturated ketones with cyanoacetamide
Authors: Al‐Hajjar Farouk H. , Jarrar Adil A.
Published: March 2009

3‐Aryl‐1‐phenyl‐2‐propen‐1‐ones Ia‐f and aroylphenylacetylenes Va‐d reacted under reflux for 3 hours with cyanoacetamide in the presence of sodium ethoxide to give the corresponding 4‐aryl‐3‐cyano‐6‐phenyl‐2‐(1H)pyridones VI. However, when ketones Ia‐e were refluxed with cyanoacetamide for one hour in the presence of sodium ethoxide or piperidine, they gave the corresponding 4‐aryl‐3‐cyano‐3,4‐dihydro‐6‐phenyl‐2‐(1H)pyridones IIIa‐e, which upon heating with selenium gave the corresponding 2‐pyridones VI. The structures of the products are based on chemical and spectroscopic evidence.
Sur la synthèse de chloro‐3 indolinones a partir de β‐nitrostyrènes diversement substitués
Authors: Guillaumel Jean , Demerseman Pierre , Clavel Jean‐Marc , Royer René
Published: March 2009

Les dérivés méthylés, chlorés ou fluorés en ortho, en méta ou en para et le dérivé nitre en méta de la chaǐne latérule du β‐nitrostyrène donnent des chloro‐3 indolinones‐2 substituées en positions correspondantes sur l'homocycle, lorsqu'on les traite par le chlorure d'acétyle, en présence de chlorure ferrique, dans le chlorure de méthylène, è 0°. Les chlorures d'aluminium et de titane ne sont pas capables d'assurer une telle hétérocyclisation et ils fournissent seulement, dans les měmes conditions, un acide N‐acétyl chloro‐2 phényl‐2 acétohydroxamique et/ou un chlorure d'acide N‐acétoxy chloro‐2 phényl‐2 acétohydroximique.
Structure de la cis‐dihydroxy‐4,5 diphényl‐3,4 méthyl‐5 isoxazoline‐2
Authors: Philoche‐Levisalles Michèle , Bellec Christian
Published: March 2009

La détermination de la structure de la cis dihydroxy‐4,5 diphényl‐3,4 méthyl‐5 isoxazoline‐2 a été effectuée par diffraction des R X sur monocristaux. Elle a mis en évidence la non‐planéité du cycle isoxazolinique et l'existence de liaisons hydrogène intra et intermoléculaires.
v‐triazolines. Part XVI. Synthesis of benzothiepino[4,5‐d]‐v‐triazole derivatives
Authors: Rossi Luisa Maria , Trimarco Pasqualina
Published: March 2009

The cycloaddition reaction of some arylazides to enamines 4a‐f afforded v‐triazolines 5a‐i; by subsequent acid‐catalyzed hydrolysis v‐triazoles 6a‐c were obtained. The reversibility of the cycloaddition was demonstrated on the basis of spectroscopic or chemical evidences.
The biological activity and crystal structure of 2‐allylamino‐4,5‐dihydro‐7,8‐dimethoxynaphtho[1,2‐d]thiazole
Authors: Rahman A. , Van Der Helm Dick , Herd Melvin D. , Hashem M. M. , Berlin K. Darrell
Published: March 2009

Screening data for the carcinostatic activity of 2‐allylamino‐4,5‐dihydro‐7,8‐dimethoxynaphtho[1,2‐d]‐thiazole is reported. Significant T/C values (survival ratio) were found when the title compound was used to treat colon 38 tumors in the testing program of the National Cancer Institute. A single crystal X‐ray diffraction analysis was made of the compound and revealed an essentially planar arrangement of the aromatic and heterocyclic rings. The compound crystallizes in the space group P21/c with cell dimensions a = 7.9177(27) Ǎ, b = 14.999(10) Ǎ, c = 13.237(4) Ǎ, β = 107.56(2)°, Z = 4 at ‐135 ± 2°C. The intensity data were collected at low temperature using CuKα radiation. The structure was determined by direct methods and refined to an R‐factor of 0.036 for the 2606 observed data. The internuclear distances were calculated between the two oxygen atoms and N(1) for comparison with such “triangulation” data of other systems with known inhibitory characteristics of cell growth.
Synthesis of quinoxaline derivatives through condensation of 1,2‐diaminobenzenes with β‐keto sulfoxides
Authors: Kano Shinzo , Shibuya Shiroshi , Yuasa Yoko
Published: March 2009

The reaction of o‐phenylenediamine with α‐methylsulfinylcyclohexanone and α‐methylsulfinylcyclopentanone in the presence of acetic acid afforded 1,2,3,4‐tetrahydrophenazine and 2,3‐dihydro‐1H‐cyclopenta[b]‐quinoxaline, respectively. 3,4‐Diaminotoluene and 3,4‐diaminochlorobenzene were reacted with α‐methyl‐sulfinylacetophenone to give a mixture of the corresponding 6‐ and 7‐substituted 2‐phenylquinoxaline. Condensation of 3,4‐diaminomethoxybenzene with α‐methylsulfinylacetophenone gave 7‐methoxy‐2‐phenylacetophenone, whereas, the same reaction between 3,4‐diaminonitrobenzene and α‐methylsulfinylacetophenone yielded 6‐nitro‐2‐phenylquinoxaline.
Reversible cyclization of N‐(3‐hydroxy‐1‐alkenyl)pyridinium salts to pyridooxazines
Authors: Carotti A. , Casini G. , Ferappi M. , Cingolani G. M.
Published: March 2009

Partially hydrogenated pyrido[2,1‐b][1,3]oxazine, cyclopenta[d]pyrido[2,1‐b][1,3]oxazine and pyrido[1,2‐a]‐[3,1]benzoxazine ring systems were easily formed in the reaction of 3‐hydroxy‐2‐(2‐hydroxy‐1,3‐dioxo‐2‐indanyl)‐2‐alken‐1‐one derivatives with tosyl chloride and pyridine bases. A facile interconversion between pyridooxazines and the corresponding pyridinium salts was also realized.
A synthesis of some novel 4,5‐dihydroazepines by the reaction of oxazolium 5‐oxides with 1,2‐dicyanocyclobutene
Authors: Turchi Ignatius J. , Maryanoff Cynthia A. , Mastrocola Antonietta R.
Published: March 2009

Heating primary or secondary α‐amino acids in acetic anhydride in the presence of 1,2‐dicyanocyclobutene leads to 4,5‐dihydroazepines via the intermediacy of mesoionic oxazolium 5‐oxides.
Reactions of ethyl cinnamates with arylacetamides
Authors: Shandala Mowafak Y. , Al‐Khashab Abdul‐Ilah Y. , Afzal M. , Ahmad Shakir S.
Published: March 2009

Reactions of ethyl cinnamates with arylacetamides gave the corresponding 2,6‐diketo‐3,4‐diarylpiperidine (1a‐o) in addition to the corresponding cinnamides (2a‐o) and arylacetates (3a‐o). The latter two are formed from the intermediates of the Claisen condensation of the reactants. On the other hand and contrary to the above results, condensation of p‐methoxycinnamate with arylacetamides gave only p‐methoxycinnamide in quantitative yields with the corresponding arylacetates.
Derivatives of perhydrofuro[2,3‐c]pyridin‐2‐one
Authors: Borne Ronald F. , Aboul‐Enein Hassan Y.
Published: March 2009

Synthetic approaches to the preparation of perhydrofuro[2,3‐c]pyridin‐2‐one derivatives as analogs of pilocarpine are reported. Derivatives of the desired ring system were obtained from iodolactonization of the appropriate tetrahydropyridyl esters.
A convenient laboratory synthesis of 2‐oxazoline
Authors: Franco Fidencio , Muchowski Joseph M.
Published: March 2009

The reaction of 2‐chloroethylformamide (1a) with sodium hydride, in N‐methyl‐2‐pyrrolidone, at reduced pressure, gave anhydrous 2‐oxazoline (2a) in good yield.
Spectroscopic evidence for the intermediacy of a 6‐R‐2,4‐diazabicyclo‐[3.1.0]hex‐2‐(3)ene in the photoisomerization of 4‐R‐1,4‐(3,4)‐dihydropyrimidines
Authors: Van Der Stoel R. E. , Van Der Plas H. C. , Geurtsen G.
Published: March 2009

1H‐ and 13C‐nmr spectroscopy is presented showing that photolysis of 4‐(p‐trifluoromethylphenyl)‐1,4‐(3,4)‐dihydropyrimidine yields 6‐(p‐trifluoromethylphenyl)‐2,4‐diazabicyclo[3.1.0]hex‐2‐(3)ene.
Alkaline hydrolysis of 3‐methyl‐4‐nitro‐5‐styrylisoxazole with Na18OH
Authors: Sarti‐Fantoni P. , Donati D. , De Sio F. , Moneti G.
Published: March 2009

The use of enriched Na18OH in the hydrolysis of 3‐methyl‐4‐nitro‐5‐styrylisoxazole leads to oxygen‐labelled cinnamic acids. Isoxazole ring opening and cleavage of title compound has been investigated.
Peptide sequencing with the 2‐pyridinecarboxaldehyde schiff base peptide degradation
Authors: Day R. A. , Jayasimhulu K. , Evans J. V. , Bhat G. , Lin L. C. , Wieser M. J.
Published: March 2009

Dedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday.

Peptides treated with 2‐pyridinecarboxaldehyde are converted to Schiff bases, pyridoimidazoles, α‐ketoacyl amino acids and peptide amides, and diketopiperazines. Nitrogen abstraction and condensation with 2‐pyridinecarboxaldehyde gives heterocyclic products. The products are separable by gas chromatography and when analyzed by mass spectrometry afford information for sequence assignment. Thus, a nonvolatile peptide can be converted to a mixture of products in one step that by mass spectrometric analysis affords the sequence. Peptides of up to eight and nine amino acids have been analyzed using this degradation as the basis of a one‐step procedure.
Mass spectral characterization of some nucleoside phosphates and phosphoramidates
Authors: Smith Ronald G. , Farquhar David
Published: March 2009

Seven new synthetic nucleotide analogues have been characterized as their trimethylsilyl derivatives by recording their electron impact mass spectra. These spectra are consistent with their expected structures, most of which possess a cyclic phosphate or phosphoramidate group.
Synthesis of 2‐amino‐3‐benzoylphenylacetic acid
Authors: Lo Young S. , Walsh David A. , Welstead William J. , Mays Richard P. , Rose Edward K. , Causey David H. , Duncan Robert L.
Published: March 2009

2‐Amino‐3‐benzoylphenylacetic acid, sodium salt was prepared from indoline through a process applicable to large scale production.
Recherche en série du triazole‐1,2,4. II‐Réactivité des amino‐4 aryl‐3 triazol‐1,2,4 ones‐5
Authors: Milcent René , Redeuilh Catherine
Published: March 2009

La Nl‐alkylation, les acylations sélectives, les réactions de condensation et diverses oxydations de l'amino‐4 phényl‐3 triazol‐1,2,4 one‐5 sont présentées. Elles permettent la synthése de nombreux composés nouveaux parmi lesquels les diaryl‐2,4 oxa‐1 tetraaza‐3,3a,5,6 pentalénes.
Natural benzofurans. Synthesis of medicagol methoxybenzofuran
Authors: Scannell Ralph T. , Stevenson Robert
Published: March 2009

A general route to 2‐arylbenzofurans, consisting of reaction of an o‐halogenophenol ester with a cuprous arylacetylide, was employed to synthesize medicagol methoxybenzofuran. 2,4‐Diraethoxyacetophenone was converted to 2,4‐dimethoxyphenylacetylene in three steps and reaction of the cuprous salt with 2‐iodo‐4,5‐methylenedioxyphenyl acetate gave the desired 2‐(2′,4′‐dimethoxyphenyl)‐5,6‐methylenedioxybenzofuran.
Rearrangement of 4‐aryl‐1,2,4‐triazine into the 4‐amino derivatives
Authors: Ibrahim Yehia A. , Eid M. M. , Abdel‐Hady S. A. L.
Published: March 2009

The action of hydrazine on 3‐methylmercapto‐5‐oxo‐4‐aryl‐4,5‐dihydro‐1,2,4‐triazines led to a novel rearrangement and gave 3‐arylamino‐4‐amino‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazines. The mechanism of this rearrangement was discussed.
The synthetic utility of heteroaromatic azido compounds. Part VII. Preparation of some 2‐ and 4‐substituted thieno[3,2‐d]pyrimidines
Authors: Westerlund Christer
Published: March 2009

Synthetically useful scission reactions of some 1H‐1,2,3‐triazolo[1,5‐a]thieno[3,2‐d]pyrimidines have been studied. The net result of these reactions is an elimination of nitrogen, and a 1,1‐addition of the cleaving agent, forming 2‐substituted thieno[3,2‐d]pyrimidines. The mechanism of the scission is discussed, and a concomitant nucleophilic attack and expulsion of nitrogen is proposed. An unusual reaction between the unsubstituted triazole‐fused parent compound (1) and bromine in alkaline medium is also reported.
Photoaddition of ketones to imidazoles, thiazoles, isothiazoles and isoxazoles. Synthesis of their oxetanes
Authors: Nakano Tatsuhiko , Rodríguez Wilma , De Roche Severina Z. , Larrauri José M. , Rivas Carlos , Pérez Carmen
Published: March 2009

Imidazole itself did not undergo photoaddition reactions with ketones. However, irradiation of 1‐acetyl and 1‐benzoylimidazole, and 1,1‐carbonyldiimidazole with benzophenone yielded oxetanes. On irradiation with carbonyl compounds, 1,2‐dimethylimidazole and 1‐benzylimidazole did not give oxetanes but a hydroxyaryl or hydroxyalkyl derivative. Thiazole itself did not yield any photoaddition product, but 2,4‐dimethylthiazole afforded oxetanes on irradiation with benzophenone and with 3‐benzoylpyridine. Irradiation of 2,4‐dimethylthiazole with acetophenone led to the formation of a dimeric material. On irradiation with benzophenone, 4‐methylisothiazole did not yield an oxetane but rather a hydroxyphenyl derivative. 3,5‐Dimethylisoxazole on irradiation with benzophenone and with 3‐benzoylpyridine gave oxetanes. Irradiation of 4,5‐dimethylisoxazole yielded similarly an oxetane with benzophenone
A novel tetracyclic ring system. 10H‐tetrazolo[5′,1′:3,4][1,2,4]triazino[5,6‐b]indole
Authors: Joshi Krishna C. , Chand Pooran
Published: March 2009

The reaction of 3‐hydrazino‐1,2,4‐triazino[5,6‐b]indole with nitrous acid affords a novel tetracyclic ring system: 10H‐tetrazolo[5′,1′:3,4][1,2,4]triazino[5,6‐b]indole. The mode of cyclization has been discussed.
Synthesis of substituted 2‐amino‐3‐(alkyl or aryl)sulfonylpyrroles
Authors: Mattson Ronald J. , Wang Li‐Chang , J. Walter Sowell
Published: March 2009

A general route for the synthesis of 2‐amino‐3‐(alkyl or aryl)sulfonyl pyrroles is reported.
Cyclic peptides from penicillium islandicum. A review and a reevaluation of the structure of islanditoxin
Authors: Ghosh Anil C. , Ramgopal Malathi
Published: March 2009

Dedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday.

The structures of cyclochlorotine and islanditoxin, cyclic peptides from Penicillium islandicum are reviewed. The peptide A isolated in these laboratories has been identified by gc/ms studies as cyclochlorotine. It is suggested that the structure of islanditoxin [cyclo‐(L‐dichloroprolyl‐D‐β‐amino‐β‐phenylpropionyl‐L‐α‐amino‐n‐butyryl‐L‐seryl‐L‐serine)] 1 should now be revised to that of cyclochlorotine, [cyclo‐(L‐dichloroprolyl‐D‐β‐amino‐n‐butyryl‐L‐seryl‐L‐β‐amino‐β‐phenyl‐propionyl‐L‐serine)] 2.
Chiral environments for asymmetric hydrogenation of model didehydro‐amino acid residues
Authors: Davies John S. , Eaton Mark C. , Ibrahim M. Nazar
Published: March 2009

Dedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday

Nmr and glc analysis of diastereoisomeric mixtures of dipeptides has been used to study the asymmetric hydrogenation of model benzoyldidehydro‐ and trifluoroacetyldidehydro‐dipeptide methyl esters. Chiral enhancement of one isomeric form appears to be independent of the N‐terminal acyl group, but is significantly influenced by the choice of amino‐acid in the C‐terminal position. C‐Terminal aromatic amino‐acids and their derivatives give the best chiral enhancement during hydrogenation of a neighbouring dehydroamino‐acid residue.
Synthesis of some N‐heteroaromatic analogues of cannabinoids
Authors: Chiodini Laura , Di Ciommo Mauro , Merlini Lucio
Published: March 2009

The synthesis of some [1]benzopyrano[3,4‐b]pyrazine, ‐[3,4‐d]imidazole, ‐[4,3‐c]imidazole, ‐[4,3‐c]pyrazole and ‐[3,4‐d]isoxazole analogues of cannabinoids is reported.
Synthesis of 2‐S‐dioxo isosteres of purine and pyrimidine nucleosides. I. Alkyl and glycosyl derivatives of 3,5‐diamino‐4H‐1,2,6‐thiadiazine 1,1‐dioxide
Authors: Resa P. Fernández , Stud M.
Published: March 2009

Preparation of alkyl and glycosyl derivatives of 3,5‐diamino‐4H‐1,2,6‐thiadiazine 1,1‐dioxide (1) is described. Reaction of 1 with dimethyl sulfate gave the 4‐methyl and 2,4‐dimethyl derivatives. With benzyl chloride and allyl bromide C‐4 substituted compounds were obtained. Reaction of the disilyl derivative of 1 with either 2,3,4,6‐tetra‐O‐acetyl‐α‐D‐glucopyranosyl bromide or 1,2,3,4,6‐penta‐O‐acetyl‐β‐D‐glucopyranose in the presence of Friedel‐Crafts catalysts afforded the α and β anomers of the N‐2 nucleoside and the β‐O‐glucoside. When the reaction was performed with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose, a β‐C‐glycoside and the α and β anomers of the N‐2 nucleoside were obtained. The structure of the corresponding nucleosides were elucidated by 1H nmr and uv by comparing the latter with those of the alkyl derivatives.
Synthesis of 2,4‐substituted 6,7‐phenanthreno‐and 6,7‐acenaphthenopteridines
Authors: Ram Vishnu J. , Pandey Hrishi Kesh , Vlietinck Arnold J.
Published: March 2009

A series of 6,7‐phenanthreno‐ and 6,7‐acenaphthenopteridines bearing different substituents at positions 2 and 4 are prepared. The structures of the compounds are confirmed by spectroscopic studies and elemental analyses.
Synthesis and reactions of 2‐chloro‐3,4‐dihydrothienopyrimidines and ‐quinazolines
Authors: Yamaguchi Hitoshi , Ishikawa Fumiyoshi
Published: March 2009

Reaction of 2,4‐dichlorothienopyrimidines and ‐quinazolines 1 with sodium borohydride gave the corresponding 2‐chloro‐3,4‐dihydro derivatives 2. Some nucleophilic substitutions of 2b afforded 2‐substituted derivatives 3b‐7b and reaction of 2g,h with ethyl bromoacetate yielded selectively the corresponding 3‐substituted compounds 8g,h which were derived to imidazo[2,1‐b]quinazolin‐2‐ones 9g,h.
Mass spectra of substituted Δ2‐1,2,4‐oxadiazolines. II
Authors: De Albuquerque Julianna F. C. , Srivastava R. M.
Published: March 2009

5,5‐Pentamethylene‐3‐(phenyl or para‐substituted‐phenyl)‐Δ2‐1,2,4‐oxadiazolines, 1a‐e, were examined by electron‐impact mass spectrometry. Defocussed metastable ion detections confirmed the formation of certain daughter fragments from the mother ions. The exact mass measurements helped to make the correct assignment of various species. We conclude that it is the spiro arrangement which caused such a dramatic change in the decomposition pattern. Several new fragmentation pathways have been found in the present studies. Out of five oxadiazolines prepared for the present work, three (1b,d,e) are new.
Reaction of some coumarin and 4,6‐diaryl‐2H‐pyran derivatives with secondary amines
Authors: El‐Kholy Ibrahim El‐Sayed , Mishrikey Morcos Michael , Feid‐Allah Hassan Mostafa
Published: March 2009

The reaction of piperidine, morpholine, piperazine or dimethylamine with several coumarins, 3‐bromocoumarin, 4,6‐diaryl‐2H‐pyran‐2‐ones and 3‐bromo‐4,6‐diaryl‐2H‐thiopyran‐2‐ones gave o‐hydroxycinnamic acid amides, benzofurans, open‐chain δ‐oxoamides and thiophene derivatives, respectively.
Reaction of ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate and ethyl ethoxymethyleneoxaloacetate with 3‐aminopyrazole analogs. Synthesis and chemistry of 3,6,7‐trisubstituted pyrazolo[1,5‐a]pyrimidine derivatives
Authors: Kurihara Takushi , Nasu Keiko , Ishimori Fumiko , Tani Tsutomu
Published: March 2009

The chemical reactivity of a series of 3‐substituted‐6‐acetyl‐7‐carbethoxypyrazolo[l,5‐a]pyrimidines (6a,b,c) and 3‐substituted‐6,7‐dicarbethoxypyrazolo[1,5‐a]pyrimidines (7a,b,c), prepared by the condensations of the 3‐aminopyrazole analogs (3a,b,c) with ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate (1) or ethyl 3‐ethoxymethyleneoxaloacetate (2), was investigated. Catalytic hydrogenation of 6 or 7 afforded 4,7‐dihydro derivatives (8 or 9). Treatment of 6a,b with acetic acid and water underwent ring transformation into 6H‐pyrazolo[1,5‐a][1,3]diazepin‐6‐ones (17a,b). By treatment with phenylhydrazine compounds of type 6 underwent cyclization to yield 2H‐dipyrazolo[1,5‐a:4′,3′‐e]pyrimidines (18a,b,c). Compounds 6 or 7 were treated with an excess of diazomethane at room temperature to give 5‐methyl‐6H‐cyclopropa[5a,6a]pyrazolo‐[1,5‐a]pyrimidines (24 and 25) in excellent yields. However, when this reaction was carried out under ice cooling, only compounds of type 23 were isolated. Reaction of 6a with ethyl diazoacetate is also described.
An improved general synthesis of 4‐aryl‐5‐pyrimidinecarboxylates
Authors: Breaux Eves J. , Zwikelmaier Kurt E.
Published: March 2009

We wish to report an improved, general synthesis of 4‐aryl‐5‐pyrimidinecarboxylates 1. Two different routes have previously been reported for the synthesis of examples of this class of pyrimidine carboxylates. The parent compound, ethyl 4‐phenyl‐5‐pyrimidinecarboxylate was prepared in low yield by the reaction of s‐triazine with ethyl benzoyl acetate. In addition, the enol ether β‐ketoaldehyde synthon, ethyl 2‐benzoyl‐3‐ethoxy‐2‐propenoate, was reported to give 1a in modest yield when reacted with guanidine (2).
The electron impact fragmentation of 3‐ and 4‐styrylpyridazine
Authors: Heresch Franz , Allmaier Guenter , Heinisch Gottfried
Published: March 2009

The electron impact mass spectrometric fragmentation of trans‐3‐ and trans‐4‐styrylpyridazine is reported in detail, including a comparison with other aza‐stilbenes. With regard to a distinction between the two isomeric styrylpyridazines, the intensity ratio of the M+ and [M‐1]+ ions, the general degree of fragmentation and the elimination pathways of nitrogen proved to be most characteristic.
Synthesis of 1‐methyl‐ and 1‐ethoxycarbonyl‐2‐phenylcarbamoylpiperidazines as potential anticonvulsant agents
Authors: Kornet Milton J. , Chu John
Published: March 2009

1‐Methyl‐ and 1‐ethoxycarbonyl‐2‐phenylcarbamoylpiperidazines were synthesized and examined for anticonvulsant activity in the maximal electroshock seizure and pentylenetetrazol seizure threshold tests. One synthetic pathway for the 1‐methyl compounds involved the reaction between aryl isocyanates and 1‐methyl‐piperidazine. A second procedure, of lesser utility, utilized selective lithium aluminum hydride reduction of 1‐ethoxycarbonyl‐2‐phenylcarbamoylpiperidazines and gave the corresponding 1‐methyl compounds. The 1‐ethoxycarbonyl series was obtained from aryl isocyanates and 1‐ethoxycarbonylpiperidazine. Several 1‐methyl‐2‐phenylcarbamoylpiperidazines exhibited significant anticonvulsant activity.
Studies on the synthesis of heterocyclic compounds. Part V. A novel synthesis of some pyridazin‐4‐(1H)one derivatives and their reaction with hydrazine
Authors: Plescia Salvatore , Daidone Giuseppe , Fabra Jole , Sprio Vincenzo
Published: March 2009

Some phenylazo derivatives of β‐dicarbonyl compounds 1a,b,c,d reacted with dimethylformamide dimethylacetal to yield new 1‐phenyl‐3‐R‐4‐(1H)pyridazinones 3a,e and 4. When compounds 3a and 3e were treated with hydrazine hydrate, they gave rise to pyrazolo[4,3‐c]pyridazines 5 and 7, respectively. By the action of hydrazine hydrate on compound 4, the 1‐phenyl‐3‐(1H‐pyrazol‐3‐yl)‐4‐(1H)pyridazinone 8 was obtained. The structures of all the new compounds were assigned on the basis of satisfactory analytical and spectroscopic data.
Reactions of 3‐acetyltropolone methyl ethers with o‐phenylenediamine. Formation of cyclohepta[b][1,5]benzodiazepine
Authors: Imafuku Kimiaki , Yamane Akio , Matsumura Hisashi
Published: March 2009

Reactions of 3‐acetyltropolone methyl ethers with o‐phenylenediamine are described. 3‐Acetyl‐2‐methoxytropone (2a) with o‐phenylenediamine in ethanol under reflux condition to afford 11‐hydroxy‐6‐methylcyclohepta[b][1,5]benzodiazepine (4), 10‐acetyl‐6H‐cyclohepta[b]quinoxaline (5), and 6‐acetyl‐5H‐cyclohepta[b]‐quinoxaline (6). The same reaction of 7‐acetyl‐2‐methoxytropone (2b) gave 7‐acetyl‐2‐(2‐aminoanilino)‐tropone (3b) besides 4, 5, and 6. The compound 4 has a 1,4‐diazaheptalene skeleton.
1‐Acetamido‐17‐carbomethoxydihydrothebainone
Authors: Archer Sydney , Okaniwa Kenichiro , Schepis Dominic J. , Moharir Yadunath E. , Klinowski Carl W.
Published: March 2009

Treatment of 1‐(5′‐benzyloxy‐4′‐methoxy‐2′‐nitrobenzyl)‐3,4‐dihydroisoquinoline 2 with lithium/ammonia followed by the addition of ethanol gave a mixture of the dibenz[b,g]indolizines 3 and 4. Omission of ethanol resulted in the formation of 3 only. The dihydroisoquinoline from 3,4‐dimethoxyphenylethyl amine behaved similarly.

Reduction of 2a with sodium/ammonia resulted in cleavage to give the nitro‐guaiacol 8. Oxidation of 2a in the presence of potassium t‐butoxide gave a complex mixture from which the benzoyldihydroisoquinoline 5 and 2‐benzyloxy‐5‐nitroanisole were isolated in low yield.

Treatment of the hexahydrobenzylisoquinoline 10 with diazotized sulfanilic acid, followed by reduction and then acetylation gave a diacetyl compound 12 which was hydrolyzed to 13. Ring closure with boron trifluoride gave the dihydrothebainone 14.
Carbocyclic analogs of thymine nucleosides and related 1‐substituted thymines
Authors: Shealy Y. Fulmer , O'Dell C. Allen , Thorpe Martha C.
Published: March 2009

The carbocyclic analogs of thymidine (IXf), 1‐β‐ribofuranosylthymine (IXg), and 1‐β‐3′‐deoxyribofuranosyl‐thymine (IXe) were synthesized by incorporating modifications into the Shaw method of synthesizing 2,4‐(1H,3H)pyrimidinediones via acryloylureas. Simpler analogs of thymine nucleosides were also prepared by this method. The carbocyclic analog of thymidine displayed modest activity against Leukemia L1210 in vivo. It differs from a compound prepared previously by a Prins reaction.
Displacement of the indolyl sulfide linkage in the synthesis of 3‐substituted indoles
Authors: Bennett Richard , Maggiolo Allison , Shah Tushar
Published: March 2009

The indolyl sulfide compounds (5,6,7,8) gave 3‐3′‐diindole methane derivatives by a double decomposition‐displacement reaction. These same compounds when reacted with alkoxides yielded 3‐alkoxy‐methylindole derivatives (9‐14).