bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon‐13 NMR studies on 3‐phenyl‐as‐triazine 4‐oxides
Authors: Bennett G. B. , Kahle A. D. , Minor H. , Shapiro M. J.
Published: April 2009

The substituent chemical shifts of a series of para substituted‐3‐phenyl‐as‐triazine 4‐oxides were studied using the Swain‐Lupton F and R values. This data was compared to that obtained for parasubstituted biphenyls, phenyl pyrroles and phenyl furans. It was found that the substituent chemical shifts in the triazines behaved in a similar manner to that in the biphenyl system.
6‐ and 7‐aryl‐1,2,4‐triazolo[4,3‐b]‐1,2,4‐triazines. Synthesis and characterization
Authors: Trust Ronald I. , Albright J. Donald , Lovell F. M. , Perkinson N. A.
Published: April 2009

Synthetic methods for the preparation of 6‐aryl‐1,2,4‐triazolo[4,3‐b]‐1,2,4‐triazines (1) and the 7‐aryl isomers (2) are described. Compounds 1 were prepared from aryl glyoxaldoximes 76 via 6‐aryl‐1,2,4‐triazin‐3(2H)ones (75). A simple procedure for the preparation of the 7‐aryl isomers was effected using arylglyoxals 11 and the triazoles (4, 12a and 12b). However, complete regioselectivity was not realized in all cases, especially when the triazoles were substituted at the C‐5 position. A regiospecific synthesis of the 7‐aryl isomers 2 was developed via the 3‐methylthio‐5‐aryl‐1,2,4‐triazines (61). The structure of the parent 6‐phenyl derivative 5 was confirmed by x‐ray crystallography.
Synthesis of 5,6‐dihydroxy‐2‐phenyl‐4‐pyrimidinecarboxylic acid, methyl ester, a corrected structure
Authors: Culbertson Townley P.
Published: April 2009

Pyrolysis of the adduct of benzamide oxime and dimethyl acetylenedicarboxylate leads to 5,6‐dihydroxy‐2‐phenyl‐4‐pyrimidinecarboxylic acid methyl ester (4a) rather than 4,5‐dihydro‐α,4‐dioxo‐2‐phenyl‐1H‐imidazole‐5‐acetic acid, methyl ester (1).
The synthesis of functionalized derivatives of pyrimido[4,5‐b][1,4]oxazines and side chain attachment
Authors: Winchester Merritt J.
Published: April 2009

The synthesis and reactions of 2‐amino‐4‐hydroxypyrimido[4,5‐b][1,4]oxazines with functionalities in the six position are described (1). The use of functionalities in the six position for coupling side chains to the pyrimido‐oxazine system is discussed and a successful coupling described.
Antiulcer agents. 2. Pyridyl oxime ethers
Authors: Moffett Robert Brace , Robert André , Schumann Edward L. , Paquette Lew A.
Published: April 2009

A large number of pyridinecarboxaldehyde (and ketone) O‐substituted oximes were prepared by alkylating the oxime or by treating the parent aldehyde (or ketone) with an O‐substituted hydroxylamine. Many of these were converted to the N‐oxide. Screening revealed that many of these oxime ethers were active in preventing gastric ulcers in rats. Data on selected examples is given.
1,2,4‐Oxadiazoles. XI. An intermediate in the isomerization from nitrones to amides
Authors: Baiocchi L. , Picconi G. , Palazzo G.
Published: April 2009

Certain 1,2,4‐oxadiazolyl‐aryl nitrones isomerize to the corresponding amides by heating in ethanol via stable intermediates, for which the structure of 1,2,4‐oxadiazolium inner salts was recognized.
Arylindoles. III. Mannich reaction of 1‐arylindoles
Authors: Khan Misbahul Ain , Rocha Emely Kazan
Published: April 2009

1‐Phenyl‐, and 1‐nitrophenylindoles when subjected to Mannich reaction conditions gave the corresponding 3‐dialkylaminomethyl derivatives (IIc‐IIk) in good yields.
Etude théorique des cycloadditions à partir dM'ylures d'azinium ou de composés homologues
Authors: Arriau Jean , Maury Catherine , Maury Georges
Published: April 2009

L'étude théorique des réactions citées dans le titre a été abordée en utilisant une méthode perturbationelle. Les résultats des calculs permettent de retrouver les orientations préférentielles expérimentales de la réaction lorsqu'elles correspondent à des différences d'énergie de stabilisation importantes.
Syntheses of 2‐hydroperoxy‐and 2‐hydroxy‐2H‐imidazoles
Authors: Graziano M. L. , Curato G. , Scarpati R.
Published: April 2009

Oxidation of fully substituted imidazoles 1 by singlet oxygen gives in good yield fully substituted 2‐hydroperoxy‐2H‐imidazoles 2. Reduction of 2 by triphenylphosphine leads to 2‐hydroxy‐2H‐irnidazoles 3. Limitations of the methods are reported.
Synthèse et réactivité de nitro indazoles
Authors: Benchidmi Mohamed , Bouchet Philippe , Lazaro RenÉ
Published: April 2009

La synthèse et les propriétés spectroscopiques en rmn de 44 dérivés nitrés de l'indazole dont 23 sont décrits pour la première fois, ont été étudiées. En fonction des rendements, on indique la meilleure voie d'accés aux dérivés halogénés méthyle's (halogénation avant ou après méthylation du nitro indazole). La réactivité' relative des différents sites du cycle vis à vis de l'agent électrophile est discutée.
Indole related compounds. Reaction of 1‐protected‐indoles with pyridine substrates
Authors: Caixach J. , Capell R. , Galvez C. , Gonzalez A. , Roca N.
Published: April 2009

The products resulting from the reactions of 1‐benzenesulfonyl‐2‐lithioindole and 2‐lithio‐1‐methylindole with different pyridine substrates (pyridine, 1‐methoxy‐pyridinium salt and 2‐bromopyridine) have been studied. The use of lithiocyclohexylisopyropylamide as a lithiating agent of indoles has been investigated. The preparation of four of the possible benzenesulfonyl derivatives of 2‐(2′ ‐pyridyl)indole is described.
Reduction of 1,2‐diaroyl‐1,2‐diazetidines by lithium aluminum hydride
Authors: Landis Michael E. , Mitchell John C.
Published: April 2009

Reaction of a series of four‐membered ring hydrazides (1,2‐diaroyl‐1,2‐diazetidines) with lithium aluminum hydride at 80° results in reductive saturation of both carbonyl groups affording 1,2‐diaryl‐1,2‐diazetidines in modest yield. Reactions at 22° result in reductive fragmentation at one carbonyl moiety, producing a monoaroyl‐1,2‐diazetidine as the exclusive product. A mechanism similar to that postulated for the temperature‐dependent reduction of amides by lithium aluminum hydride is proposed for the reduction of these 1,2‐diazetidines.
Zur photochemie des β‐pyridinalanilins
Authors: Behjati B. , Bluhm Th.
Published: April 2009

β‐Pyridinalanilin läβt sich im Gegensatz zu alien anderen als Schiffsche Base vorliegenden Diazastilbenen nicht zu Diazaphenanthrenen cyclisieren. Stattdessen ergibt sich durch Photohydration Chinolin‐3‐aldehyd.
Zur photolyse des benzotriazols
Authors: Razmara F. , Behjati B. , Aftandilians N. , Bluhm Th.
Published: April 2009

The photolysis of 1H‐benzotriazole in the presence of benzene produces two products, namely 2‐aminobiphenyl and 1‐anilinobenzotriazole isolated as 2‐acetylaminobiphenyl and 1‐(N‐ acetylanilino)benzotriazole, respectively, upon chromatography on Kieselgel 60.
1,2,4‐triazines. 2. A convenient one‐pot procedure for the preparation of 3,5 (2H,4H)‐1,2,4‐tnazinedione (6‐azauracil)
Authors: Lovelette Charles A.
Published: April 2009

A procedure for the preparation of 5‐azauracil is described.
Préparation d'isoxazoles trisubstitués par réduction chimique et électrochimique d'α‐acyl β‐nitrostilbènes
Authors: Bellec Christian , Bertin Daniel , Colau Roger , Deswarte StÉPhane , Maitte Pierre , Viel Claude
Published: April 2009

La nitration par le peroxyde d'azote d'α‐acylstilbènes conduit aux α‐acyl β‐nitro stilbènes correspondants. Ceux‐ci, par réduction chimique ou électrochimique en milieu acide, conduisent, avec de bons rendements, à des isoxazoles trisubstitués.
Synthesis of Pyranthiones
Authors: Van Allan J. A. , Reynolds G. A. , Stenberg J. F.
Published: April 2009

A general method for the preparations of pyranthiones is particularly useful for preparing substituted xanthiones which are unavailable by established procedures. Reaction of a xanthone with p‐tosyl isocyanate or with trichloroacetyl isocyanate produces the corresponding imino derivatives, which upon treatment with n‐butylamine followed by hydrogen sulfide gives the desired xanthione in good yield.
A Convenient Synthesis of Certain Benzo and Dibenzoxanthones and Chromones
Authors: Van Allan J. A. , Stenberg J. F. , Reynolds G. A.
Published: April 2009

Certain chromones and benzoxanthones were prepared by heating at 300–325° a mixture of 1‐or 2‐naphthol with either phenyl o‐hydroxybenzoate or o‐hydroxynaphthoate or a β‐ketoester. The yields and purity of the products are superior to those obtained by the published procedures.
Constituents of cannabis sativa L. XVI. A possible decomposition pathway of Δ9‐tetrahydrocannabinol to cannabinol
Authors: Turner Carlton E. , Elsohly Mohmoud A.
Published: April 2009

A pathway is proposed for the decomposition of Δ9‐tetrahydroeannabinol (I) and its Δ8‐isomer (IX) with the eventual formation of cannabinol (II) through epoxy and hydroxylated intermediates.
Hétérocyclisation de la nor‐3 ar‐himachalone‐9
Authors: Fkih‐Tetouani Souâd , Daunis Jacques , Jacquier Robert , Viallefont Philippe
Published: April 2009

Nous avons pu facilement accoler au cycle à sept chainons de la nor‐3 ar‐himachalone‐9 différents hétérocycles à trois ou cinq chainons; la formation d'hétérocycles à six chainons est beaucoup plus difficile, celle d'hétérocycles à sept chainons n'a pas été possible.
Angular polycyclic thiophenes containing two thiophene rings. I
Authors: Kudo Hirotaka , Tedjamulia Marvin L. , Castle Raymond N. , Lee Milton L.
Published: April 2009

We describe the synthesis of thieno[2,3‐c]dibenzothiophene (6), thieno[3,2‐c]dibenzothiophene (10), thieno‐[3,2‐a]dibenzothiophene (14), thieno[2,3‐a]dibenzothiophene (16), benzo[1,2‐b:4,3‐b]bisbenzo[b]thiophene (18), benzo[1,2‐‐6:3,4‐b]bisbenzo[b]thiophene (20), benzo[2,1‐‐6:3,4‐b]bisbenzo[b]thiophene (22), benzo[1,2‐b:3,4‐g]bisbenzo[b]thiophene (27), benzo[1,2‐b:4,3‐e]bisbenzo[b]thiophene (29), benzo[2,1‐‐6:3,4‐g]bisbenzo[b]thiophene (36), benzo[2,1‐‐6:4,3‐e]bisbenzo[b]thiophene (38), benzo[1,2‐‐6:4,3‐g]bisbenzo[b]thiophene (41), benzo[1,2‐b:4,5‐g]bisbenzo[b]thiophene (42), benzo[1,2‐b:3,4‐e]bisbenzo[b]thiophene (44) and benzo‐[1,2‐b:5,4‐e]bisbenzo[b]thiophene (45).
Reactivity of thienopyrroles. Synthesis of isomeric nitro and bromothienopyrroles
Authors: Eras J. , Gálvez C. , Garct́a F.
Published: April 2009

The preparation of ethyl 2‐bromothieno[2,3‐b]pyrrole‐5‐carboxylate, ethyl 2‐bromothieno[3,2‐b]pyrrole‐5‐carboxylate, ethyl 2‐nitrothieno[2,3‐b]pyrrole‐5‐carboxylate and ethyl 2‐nitrothieno[3,2‐b]pyrrole‐5‐carboxylate are described.
Synthesis and reactivity of new l‐(1‐adamantyl)pyrazoles
Authors: Cabildo P. , Claramunt R. M. , Elguero J.
Published: April 2009

Using 1‐adamantylhydrazine as starting material, a series of 1‐(1‐adamantyl)pyrazoles has been prepared. Electrophilic reactivity (bromination and nitration) and nucleophilic reactivity (quaternarization) have been studied. Proton nuclear magnetic resonance spectra of all the new compounds are recorded.
Reaction of 2‐phenyl‐4‐methyl‐Δ2‐oxazolin‐5‐one with imines. A convenient synthesis of 3‐amido‐β‐lactams
Authors: Sain B. , Baruah J. N. , Sandhu J. S.
Published: April 2009

Azlactone 3a reacted with furan‐2‐aldehyde and thiophene‐2‐aldehyde imines to give corresponding 3‐amido‐β‐lactams in good yields.
Basicity of azoles. IV. Empirical relationships between basicity and ionization potential for aromatic five membered rings containing nitrogen or oxygen
Authors: Catalán Javier , Elguero José
Published: April 2009

A plot of pKa values for eleven azoles and benzazoles vs the experimental ionization energy of the nitrogen lone pair shows the existence of three groups of compounds: simple unsubstituted azoles (imidazole, pyrazole, oxazole, isoxazole), unsubstituted benzazoles (benzimidazole, 1H‐indazole and benzoxazole, including imidazo [1,2‐a]pyridine) and benzazoles carrying a methyl group α‐ to the basic centre (2‐methylbenzimidazole, 2‐methylindazole and 2‐methylbenzoxazole).
The reaction of lithium phenylacetylide and phenyllithium with N‐(ω‐Bromoalkyl)phthalimides
Authors: Torian Bruce E. , Braun Loren L.
Published: April 2009

Lithium phenylacetylide reacted with short‐chain N‐(ω‐bromoalkyl)phthalimides 1b and 1c to give tricyclic products 2b and 2c in moderate yields. Likewise, tricyclic products 3a‐c were obtained when short‐chain imides 1a‐c were treated with phenyllithium. When longer‐chain imides 1d‐f in this series were treated with lithium phenylacetylide only tertiary alcohols 4d‐f could be isolated. Partial hydrogenation of 2b and 2c yielded the corresponding alkenes 5b and 5c, products which corroborated the structural assignment of 2b and 2c.
A facile and general entry to optically active pheromones and aromas with γ‐alkyl‐γ‐lactone structures. A study of some lactone derivatives of pentoses
Authors: Cardellach J. , Font J. , Ortuño R. M.
Published: April 2009

A new and easy general methodology has been developed to prepare γ‐alkyl‐α,β‐butenolides or γ‐alkylbutyrolactones in four and five steps, respectively, from D‐ribonolactone as a common chiral starting material. Some of these products have pheromonal activity in insects and are also used as fruit fragrances. A study on several derivatives of D‐ribonolactone and 2‐deoxy‐D‐ribonolactone has been carried out in order to explore alternative routes for these syntheses.
Application of the okahara cyclization to the preparation of crown ethers with aromatic units
Authors: Czech B. , Czech A. , Bartsch R. A.
Published: April 2009

A series of crown ethers with single benzene, naphthalene, biphenyl and binaphthyl units are prepared by the intramolecular Okahara cyclization of appropriate symmetrical diols. The method is used to synthesize new crown ether compounds and to prepare previously‐reported crown ethers in improved yields.
Reaction of dichloroketene and sulfene with N,N‐disubstituted α‐aminomethyleneketones. Synthesis of pyrano[2,3‐e]indazole and 1,2‐oxathiino[6,5‐e]indazole derivatives
Authors: Mosti Luisa , Menozzi Giulia , Schenone Pietro
Published: April 2009

The polar 1,4‐cycloaddition of dichloroketene to N,N‐disubstituted (E)‐5‐aminomethylene‐1,5,6,7‐tetrahydro‐(1‐methyl)(1‐phenyl)‐4H‐indazol‐4‐ones V, prepared from 1,5,6,7‐tetrahydro‐(1‐methyl)(1‐phenyl)‐4H‐indazol‐4‐ones via the 5‐hydroxymethylene derivatives, gave in good yield N,N‐disubstituted 4‐amino‐3,3‐dichloro‐4,5,6,7‐tetrahydro‐(7‐methyl)(7‐phenyl)pyrano[2,3‐e]indazol‐(3H)ones VI, which are derivatives of the new heterocyclic system pyrano[2,3‐e]indazole. Dehydrochlorination of VI with DBN afforded N,N‐disubstituted 4‐amino‐3‐chloro‐6,7‐dihydro(7‐methyl)(7‐phenyl)pyrano[2,3‐e]indazol‐2(5H]‐ones VII generally in satisfactory yield. Full aromatization with DDQ of VII was tried only in the case of dimethylamino derivatives, giving a moderate yield of 3‐chloro‐4‐dimethylamino(7‐methyl)(7‐phenyl)pyrano[2,3‐e]indazol‐2(7H)‐ones. Cycloaddition of sulfene to V occurred only in the case of aliphatic N‐substitution to give in moderate yield 4‐dialkylamino‐4,5,6,7‐tetrahydro‐(7‐methyl)(7‐phenyl)‐3H‐1,2‐oxathiino[6,5‐e]indazole 2,2‐dioxides, which are derivatives of the new heterocyclic system 1,2‐oxathiino[6,5‐e]indazole.
Reaction of nitriles under acidic conditions. Part III. A facile synthesis of thienopyrimidin‐4(3H)‐ones
Authors: Shishoo C. J. , Devani M. B. , Pathak U. S. , Ananthan S. , Bhadti V. S. , Ullas G. V. , Jain K. S. , Rathod I. S. , Talati D. S. , Doshi N. H.
Published: April 2009

A variety of thiophene o‐aminoesters were reacted with cyanates, thiocyanates, cyanamides, acyl cyanides and α‐functionalized acetonitrile derivatives to yield the corresponding 2‐substituted thienopyrimidin‐4(3H)‐ones.
Ylides of heterocycles. VII.. I‐, N‐, P‐ and S‐ylides of pyrimidones
Authors: Habib Nargues Samuel , Kappe Thomas
Published: April 2009

The reaction of pyrimidone derivatives 1a‐d with iodosobenzene prepared in situ from diacetoxyiodobenzene or dichloroiodobenzene afforded the iodonium‐ylides 2a‐d in good yields. Their thermal rearrangement produced 5‐iodo‐4‐phenoxy‐pyrimidin‐6(1H)‐ones 3a‐c. Reductive deiodination of 3 gave the corresponding 4‐phenoxypyrimidin‐6(1H)‐ones 4a‐c. Acid catalized treatment of the iodonium‐ylides 2a‐d with nucleophiles such as pyridine, nicotinamide, isoquinoline, or triphenylphosphine produced the corresponding N‐ or P‐ylides 7, 8, 9, and 10, respectively. The thiophanium‐ylides 11a,c were obtained from the iodonium‐ylides 2 without the use of a catalyst. The pyridinium‐ylides 7 have been also prepared from the 5‐halopyrimidones 5 or 6 which in turn could be obtained from the reactive iodonium‐ylides 2 with hydrochloric or hydrobromic acid, respectively.
A simple and stereoselective synthesis of 7‐azabicyclo[2.2.1]‐heptane‐1,2,3,4‐tetracarboxylates
Authors: Zaima Tadataka , Matsuno Chikashi , Matsunaga Yoshiharu , Mitsuhashi Keiryo
Published: April 2009

The photoinitiated reaction of 1,1′‐bis(methoxycarbonyl)divinylamine with various maleates and fumarates afforded novel 7‐azabicyclo[2.2.1]heptane‐1,2,3,4‐tetracarboxylates. The spectral investigation of the products showed that the reaction proceeded stereoselectively, retaining the original configuration of the reagents.
Heterocycles from nitrile oxides. II . 1,2,4‐oxadiazin‐6‐ones
Authors: Hussein Ahmad Q. , El‐Abadelah Mustafa M. , Sabri Wail S.
Published: April 2009

Condensation of arylnitrile oxides with α‐amino acid esters, other than those of glycine and analine, has been found to constitute a synthetic route to the hitherto unknown 1,2,4‐oxadiazin‐6‐ones 7. α‐Amino alcohols yield with nitrile oxides the corresponding acyclic N‐(arylhydroxamoyl)amino alcohols, which are also accessible by borohydride reduction of compounds 7. In contrast, the adducts formed from nitrile oxides and α‐amino acids are unstable; they decompose readily into the aldehyde, derived from the amino acid, together with the aldoxime, derived from the nitrile oxide. Both decomposition products are also formed when compounds 7 are subjected to mild hydrolysis.
New synthesis of pyrazole and isoxazole derivatives
Authors: Molina P. , Fresneda P. M.
Published: April 2009

A convenient synthesis of 5‐aryl‐1‐phenylpyrazoles and 5‐arylisoxazoles, from readily available ketimine 1 dimethylformamide dimethylacetal and phenylhydrazine or hydroxylamine, is described.
Substitution and ring closure reactions of phthalazine derivatives
Authors: Badr M. Z. A. , El‐Sherief H. A. , El‐Naggar G. M. , Mahgoub S. A.
Published: April 2009

1‐(Phenylthio)‐ and 1‐(hydroxycarbonylmethylthio)‐4‐methylphthalazines were prepared from 1‐chloro‐4‐methylphthalazines (1). A series of 2‐benzyl‐ and benzenesulphonyl derivatives was prepared from the corresponding halides and 4‐methyl‐1(2H)‐phthalazinone (4). 4‐Methyl‐1(2H)‐phthalazinthione (6) was substituted at SH group to give 1‐(benzylthio)‐ and 1‐(ethoxycarbonylmethylthio)‐4‐methylphthalazines, 7 and 8 respectively. Treatment of hydrazine hydrate with 8 produced 1‐hydrazino‐4‐methylphthalazine (10). However, when the latter compound was treated with 1 it gave 1,2‐bis‐(4‐methylphthalazinyl)hydrazine.

Treatment of 10 with aromatic aldehydes in glacial acetic acid gave the corresponding 3‐phenyl‐s‐triazolo‐[3,4‐a]‐6‐methylphthalazines 13. 1‐Hydrazino‐4‐methylphthalazine (10) underwent cyclization reactions with acetic anhydride, ethyl chloroformate, carbon disulphide, ethylformate, ethyl oxalate and with nitrous acid to give the corresponding triazolo‐, triazino‐ and tetrazolophthalazine compounds.
Convenient synthesis of arylazo derivatives of quinoxaline, 1,4‐benzothiazine, and 1,4‐benzoxazine
Authors: Párkányi Cyril , Abdelhamid Abdou O. , Shawali Ahmad S.
Published: April 2009

Arylazo derivatives of quinoxaline (1,4‐benzodiazine), 1,4‐benzothiazine, and 1,4‐benzoxazine have been prepared by condensation of hydrazidoyl halides with o‐phenylenediamine, o‐aminothiophenol, and o‐aminophenol, respectively (Table I). This method seems to be more general than the approach using coupling of reactive diazonium salts with, e.g., 277–1,4‐benzothiazine. Both the spectral data and the results of HMO calculations of bonding energies of the azo compounds obtained in this study indicate that they exist predominantly in the hydrazone tautomeric form.
Dehydrogenation reactions of 1‐substituted‐3‐aryltetrahydroisoquinoline derivatives
Authors: Domínguez Esther , Lete Esther
Published: April 2009

The 1‐substituted‐3‐aryltetrahydroisoquinolines I have been converted into the corresponding 3,4‐dihydroor isoquinoline derivatives by treatment with several oxidizing agents: iodine in ethanol, palladium on carbon, DDQ and Fremy's salt. The oxidation reactions with iodine always resulted in the formation of the 3,4‐dihydroisoquinolines II, whereas the use of palladium on carbon and the DDQ led to the aromatic isoquinolines. Both the 3,4‐dihydro‐ and the isoquinoline derivatives were obtained by means of Fremy's salt.
Facile synthesis of 5‐(α‐alkyl‐substituted) furans
Authors: Adembri Giorgio , Anselmi Cecilia , Celli Angela M. , Lampariello Lucia R. , Scotton Mirella
Published: April 2009

2‐Halo, 2‐hydroxy‐ or 2‐alkoxyalkyl substituted furans are easily synthesized under acidic conditions by intramolecular cyclization of α,β‐unsaturated 1,4‐diketones by a simple and cheap procedure. Some aspects of the mechanism are discussed.
Synthesis of 1H‐imidazo[3′,4′:4,5]thieno[2,3‐b]pyridines. A new ring system
Authors: Guerrera Francesco , Siracusa Maria Angela , Tornetta Benedetto , Bousquet And Ennio , Agozzino Pasquale , Lamartina Liliana
Published: April 2009

A facile and convenient synthesis of the title compounds is described, using as starting materials the 2‐nitro‐3‐aminothieno[2,3‐b]pyridines. Mass spectral data of the above mentioned compounds are briefly discussed.
Synthesis of 1,4‐bis(4‐pyridyl)butadiyne
Authors: Ciana Leopoldo Delia , Haim Albert
Published: April 2009

2‐Methyl‐4‐(4‐pyridyl)‐3‐butyn‐2‐ol (2) was prepared in 70% yield by the reaction of 4‐bromopyridine with 2‐methyl‐3‐butyn‐2‐ol in diethylamine in the presence of bis(triphenylphosphine)palladium(II) chloride and copper(I) iodide. Removal of the protective group in 2 by refluxing with sodium hydroxide in toluene yields (90%) 4‐ethynylpyridine (3). Oxidative coupling of 3 in pyridine by dioxygen in the presence of copper(I) chloride produces a 92% yield of 1,4‐bis(4‐pyridyl)butadiyne.
Synthesis of 5,7‐dichloro‐2H‐1‐benzopyran‐2‐ol
Authors: Stokker G. E.
Published: April 2009

The reaction of 4,6‐dichloro‐2‐(methylthiomethoxy)cinnamaldehyde (3) or 4,6‐dichloro‐2‐hydroxycinnamaldehyde (5) with mercuric chloride in hot aqueous acetonitrile gave 5,7‐dichloro‐2H‐1‐benzyopyran‐2‐ol (4) in good yield.
Reactions of 3‐acetyl‐2‐aminotropones and 2‐acetyl‐7‐aminotropones with hydrazine
Authors: Imafuku Kimiaki , Shimazu Akiko
Published: April 2009

3‐Acetyl‐2‐aminotropone (1a) reacted with hydrazine to afford its hydrazone (3a) and 3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐one (4), while methylamino‐ and pyrrolidinyl‐substituted compounds 1b and 1c gave only the cyclized compound (4). Reactions of 2‐acetyl‐7‐aminotropones 2a‐d gave their hydrazones 5a‐d and the hydrazone 6. The hydrazones 3a and 5b were heated in acetic acid to give 4 and 3‐methyl‐8‐methylamino‐1,2‐diazaazulene (7), respectively. Several reactions of 4 and 6 were also described.
Synthesis of C‐nucleoside isosteres of 9‐(2‐hydroxyethoxymethyl)guanine (acyclovir)
Authors: Mitchell William L. , Hill Malcolm L. , Newton Roger F. , Ravenscroft Paul , Scopes David I. C.
Published: April 2009

Syntheses of 2‐amino‐7‐(2‐hydroxyethoxymethyl)imidazo[5,1‐f]‐1,2,4‐triazin‐4(3H)‐one (2) and 6‐amino‐3‐(2‐hydroxyethoxymethyl)‐1,2,4‐triazolo[3,4‐f]‐1,2,4‐triazin‐8(7H)‐one (3), novel isosteres of the antiviral agent acyclovir, are reported.
The reactions of some ortho‐substituted anilines with various α,β‐acetylenic ketones. A route to substituted quinolines
Authors: Sinsky M. S. , Bass R. G.
Published: April 2009

The reactions of some ortho‐substituted anilines with various α,β‐acetylenic ketones were investigated as a route to 4‐alkyl‐, 4‐aryl‐, 4‐hydroxy‐, and 4‐amino‐3‐quinolyl ketones. The anilines examined were 2‐aminoacetophenone (1), 2‐aminobenzophenone (2), anthranilonitrile (3), methyl anthranilate (4), and ethyl anthranilate (5). The acetylenic ketones used were 1,4‐diphenyl‐2‐butyne‐1,4‐dione (6), 3‐butyn‐2‐one (7), 1,3‐diphenyl‐2‐propyn‐1‐one (8), and 4‐phenyl‐3‐butyn‐2‐one (9). The acetylenic ketones typically reacted with the anilines to give enamines; however, exceptions were found. Acetylene 6 reacts with 3 to give the enamine (13) along with a small amount of 2,3‐dibenzoyl‐4‐quinolamine (14). The reactions of 1 or 2 with 6 give the respective quinoline derivatives directly. Acetylene 8 reacts with 2 to give 3‐benzoyl‐2,4‐diphenylquinoline (22) directly, whereas no reaction occurs between 8 and 1 or 3. Acetylene 9 does not react with 1, 2, or 3. The enamines exist as the intramolecularly hydrogen bonded isomers and usually undergo cyclization with 5 molar equivalents of methanolic sodium methoxide to give quinoline derivatives. The 4‐quinolinols exist predominantly as the 4‐quinolinone tautomer.
2H‐3,1‐benzoxazine‐2,4‐(1H)‐dione (isatoic anhydride). 15. Reactions with lactone enolates
Authors: Coppola Gary M.
Published: April 2009

The reaction of N‐methylisatoic anhydride, 1, with the lithium enolates derived from various butyrolactones or δ‐valerolactone produces stable anthranoyl lactone derivatives 4. Heating these products in toluene results in a cyclization to afford 4‐hydroxy‐3‐(2‐hydroxyalkyl)‐1‐methyl‐2(1H)‐quinolinones, 8 and 14, in good yields.
The reaction of isothiocyanates with 2‐cyanoethanoic acid hydrazide. A novel synthesis of 1,3,4‐thiadiazoles
Authors: Elmoghayar Mohamed Rifaat Hamza , Abdalla Sanaa Osman , Nasr Mohamed Yousry Abdel‐Samad
Published: April 2009

Benzoyl and ethoxycarbonyl isothiocyanates reacted with 2‐cyanoethanoic acid hydrazide 2 to afford 1‐cyanoacetyl‐4‐substituted thiosemicarbazide (5a,b). Compound 5a afforded the pyrazolo[1,5‐a]‐s‐triazine derivative 6 on treatment with 5% potassium hydroxide, and cyclised to 2‐benzoylamino‐5‐cyanomethyl‐1,3,4‐thiadiazole (8) when boiled under reflux in glacial acetic acid. Compound 8 condensed with aromatic aldehydes to yield the corresponding arylidene derivatives 9a‐c. It undergoes coupling with aromatic diazonium salts to afford the hydrazones 11a‐c. Similarly, it coupled with diazotised aminopyrazole to afford the cyclic product 12.
Synthesis of some triazole, tetrazole, and tetrazine derivatives from N‐β‐naphthalenesulfonylbenzohydrazidoyl chlorides
Authors: Hassaneen Hamdi M. , Fahmi Abdelgawad A. , Abdelhamid Hyam , Yassin Ahmady A. , Shawali Ahmad S.
Published: April 2009

A series of N‐β‐naphthalenesulfonylbenzohydrazidoyl chlorides 8a‐d has been prepared by the action of thionyl chloride on the corresponding hydrazides 7a‐d. Treatment of 8 with triethylamine and morpholine afforded the tetrazines 10 and the amidrazones 11 respectively. Acid hydrolysis of 11 yielded the hydrazides 7. Reaction of 8 with phenylhydrazine gave 3,5‐diaryltetrazoles 14. However, reaction of 8 with aroylhyrazines yielded 3,5‐diaryl‐4‐β‐naphthalenesulfonylamino‐4H‐1,2,4‐triazoles 15. The structures of the products were assigned upon the basis of their spectra, elemental analyses and alternate synthesis whereever possible.
A practical synthesis of 1,3,4,14b‐tetrahydro‐2‐methyl‐10H‐pyrazino‐[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepine (1:1) maleate
Authors: Boyer S. K. , Fitchett G. , Wasley J. W. F. , Zaunius G.
Published: April 2009

A practical synthesis of the anti‐depressant, 1,3,4,14b‐tetrahydro‐2‐methyl‐10H‐pyrazino[1,2‐a]pyrrolo‐[2,1‐c][1,4]benzodiazepine (1:1) maleate (Aptazapine 10) is reported in seven steps and approximately 20% overall yield. The key step of the synthesis was the formation of the tricyclic intermediate methyl 10,11‐dihydro‐5H‐pyrrolo[2,1‐c][1,4]benzodiazepine‐11‐carboxylate (7) via a “Pictet‐Spengler” type condensation of o‐aminobenzylpyrrole (6) and methyl glyoxylate or the methoxy hemiacetal thereof.
Mass spectral fragmentation patterns of heterocycles. VII . Reinvestigation of fundamental processes in phenothiazines
Authors: Hallberg Anders , Al‐Showaier Ibrahim , Martin Arnold R.
Published: April 2009

Electron impact induced fragmentation patterns of simple phenothiazines have been reinvestigated using metastable ion studies, exact mass measurements and deuterated derivatives. Secondary fragmentation processes involving ions m/e 198, 171, 167, 166, 154, 140 and 139 have been clarified. Mechanisms for the release of sulfur (SH· and CSH·) nitrogen (HCN and H2CN·) containing fragments from phenothiazine molecular ion are proposed based on the deuterium content of the daughter ions obtained from 1,9‐dideutenophenothiazine. A revised mechanism for the expulsion of ketene from 10‐acetylphenothiazine is suggested based on the fragmentation pattern of the 1,9‐dideuterioderivative. The composition of m/e 140 was determined by high resolution measurement to be C10H6N and not C11H7 as previously reported.
Synthesis of some 1,3,8‐trisubstituted pyrimido[4,5‐c][2,7]‐naphthyridin‐6‐ones as potential antitumor agents
Authors: Gangjee Aleem , O'Donnell John K. , Bardos Thomas J. , Kalman Thomas I.
Published: April 2009

Condensation of three 2,4‐disubstituted 6‐aminopyrimidines with methyl 1‐benzyl‐4‐oxo‐3‐piperidinecarboxylate afforded, in each case, new tricyclic, angular 1,3,8‐trisubstituted pyrimido[4,5‐c][2,7]naphthyridin‐6‐ones. 2,4,6‐Triaminopyrimidine gave the 7,8,9,10‐tetrahydrocyclo condensed product 5 as anticipated. However, the use of 2‐amino‐4‐oxo‐ or 2,4‐dioxo‐6‐aminopyrimidine afforded the dehydrogenated, 9,10‐dihydrotricyclic products 11 and 12. The growth of leukemia L1210 cells in culture were inhibited 50% by the 1,3‐diamino analog 5 at 2 × 10−6M and by the 1,3‐dioxo analog 12 at 10−5M.
Crystal structure determination of 2′‐nitro‐10‐phenylphenothiazine
Authors: Jovanovic Misa V. , Biehl Edward R. , De Meester Patrice , Chu Shirley S. C.
Published: April 2009

The structure of the titled compound, 4, has been solved by x‐ray analysis. One of the important structural features of 4 is that the 2′‐nitrophenyl group is in the plane bisecting the phenothiazine ring which is in contrast to that of 10‐(2′‐pyrazyl)phenothiazine of 4′‐nitro‐10‐phenylphenothiazine in which the 10‐aryl group is perpendicular to the plane bisecting the phenothiazine ring. The structure of 4 is in agreement with its 1H and 13C nmr data which indicate that resonance interactions between the 2′‐nitrophenyl group and the lone pair of electrons on N10 are hindered sterically by the 2′‐nitro group.
The preparation of new chiral diphenyl‐substituted macrocyclic polyether‐diester compounds and their enantiomeric recognition of chiral organic ammonium salts
Authors: Bradshaw Jerald S. , Thompson Patricia K. , Izatt Reed M. , Morin Frederick G. , Grant David M.
Published: April 2009

A series of chiral diphenyl‐substituted macrocyclic polyether‐diester ligands have been prepared from the chiral diphenyl‐substituted tetraethylene glycol. Enantiomeric recogntion by the chiral diphenyl‐substituted pyridino‐diester‐18‐crown‐6 compound (7) was studied by temperature dependent 1H NMR spectroscopy in deuteriodichloromethane. This ligand exhibited chiral recognition when complexed with the hydrogen per‐chlorate salts of (R)‐ and (S)‐α‐(1‐naphthyl)ethylamine and (R)‐ and (S)‐methyl phenylalaninate.
Synthesis and some reactions of 7‐methyl‐5‐phenyl‐5H‐pyrazolo[3,4‐e]1,2,4‐triazine‐3‐thiol
Authors: Youssef Mohamed Salah Kamel , Atta Ferial Mohamed , Hassan Khairy Mohamed , Abbady Mohamed Saad
Published: April 2009

The title compound II has been prepared by the reaction of 3‐methyl‐1‐phenyl‐4‐oxo‐5‐pyrazolone with thiosemicarbazide in aqueous potassium carbonate. Alkylation of II on the sulfur atom in aqueous sodium hydroxide afforded the 3‐alkylthio derivatives III. Interaction of II or III with different amines yielded the 3‐amino derivatives IV. The 3‐hydrazino derivative IVa condensed with aromatic aldehydes in ethanol or acetic acid giving the corresponding hydrazones V.
Synthesis of 17β‐acetamido‐3‐aza‐A‐homo‐4α‐androsten‐4‐one
Authors: Athanasiou Catherine , Catsoulacos Panayotis
Published: April 2009

A synthetic approach for the preparation of 17β‐acetamido‐3‐aza‐A‐homo‐4α‐androsten‐4‐one is described.
Reactivity of a tetrahedral intermediate in hydrolysis of N‐acetylpyrrole
Authors: Cipiciani Antonio , Savelli Gianfranco , Bunton Clifford A.
Published: April 2009

Base hydrolysis of N‐acetylpyrrole (1a) involves formation of an anionic tetrahedral intermediate (2a). The equilibrium constant between these two species can be estimated by extrapolation based on the equilibrium constants for hydration of N‐trichloroacetyl‐ and N‐trifluoroacetylpyrrole and the estimated pKa for deprotonation of the hydrates of these compounds. Inductive effects upon hydration and deprotonation of the hydrates were estimated by analogy with inductive effects upon the equilibrium reactions of chloral and acetaldehyde. The free energies of activation for formation and return of 2a are approximately 16 and 12.5 Kcal mole−1 respectively and for conversion of 2a to products 11 Kcal mole−1 in aqueous 1M OH−.
Addition reactions of thiophenols with dihydro‐ and tetrahydropyridinecarbonitriles. A comparison with reactions of phenols
Authors: Butt Graeme L. , Deady Leslie W.
Published: April 2009

p‐Chlorothiophenol reacts with 1‐methyl‐1,2,5,6‐tetrahydropyridine‐X‐carbonitriles (1, X = 4, 6, X = 3) and with 1‐methyl‐1,Y‐dihydropyridine‐3‐carbonitrile (7, Y = 6, 8, Y = 4) to give the anticipated addition products. Geometric isomers were formed from 6, but not from 1, and the stereochemistry of the products has been determined. The chemistry of the reactions with p‐cresol was quite different. No reaction occurred with 6 or 7, while 8 gave a 6‐(2‐hydroxy‐5‐methylphenyl)‐ derivative, analogous to the unexpected product obtained previously from 1.
Synthesis of 1,2:5,6‐Di‐O‐isopropylidene‐3‐O‐[3‐(5‐fluorouracil‐1‐yl)‐propionoyi]‐α‐D‐glucofuranose and its antitumor activity
Authors: Ouchi Tatsuro , Jokei Satoshi , Fujie Hirotoshi , Chikashita Hidenori , Inoi Takeshi
Published: April 2009

In order to provide a less toxic 5‐fluorouracil derivative, 1,2:5,6‐di‐O‐isopropylidene‐3‐O‐[3‐(5‐fluorouracill‐yl)‐propionoyl]‐α‐D‐glucofuranose, which was the derivative of 5‐fluorouracil combining indirectly to 3‐position of diacetoneglucose, was synthesized, and its antitumor activity was tested.
New heterocyclic syntheses from hydrazidoyl halides. Convenient syntheses of fused pyrimidines, pyridazines, and quinazolines
Authors: Abdehamid Abdou O. , PÁrkÁnyi Cyril , Shawali Ahmad S. , Abdalla Magda A.
Published: April 2009

Aminocyanopyrazole derivatives and pyrazolo[2,3‐a]quinazolones were obtained in good yields from hydrazidoyl halides and malononitrile. Pyrazolo[3,4‐d]pyridazine and pyridazo[4′,5′: 1,2]pyrazolo[1,5‐a]quinazoline derivatives were synthesized in quantitative yields by reaction of hydrazine hydrate with 2 and 16, respectively. A novel ring system, a 3‐substituted tetrahydro derivative of 7‐oxo‐6H,8H‐pyridazo[3′,4′,5′‐c'd']‐pyrazolo[3,4‐d]pyrimidine was prepared by reaction of 6 with dimethyl carbonate. Pyrazolo[3,4‐d]pyrimidine‐4,6‐dithiones were obtained in good yields by reaction of 2 with carbon disulfide. The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectral data, and alternate synthesis wherever possible. The structures of the parent fused heterocyclic systems discussed in this work are summarized in Scheme 1.
Phase transfer catalyzed synthesis of indazoles from o‐alkylbenzenediazonium tetrafluoroborates
Authors: Bartsch Richard A. , Yang Il‐Woo
Published: April 2009

Reactions of o‐methyl‐ and o‐ethylbenzenediazonium tetrafluoroborates with two equivalents of potassium acetate and five mole percent of 18‐crown‐6 in ethanol‐free chloroform produce indazoles in good to excellent yields. Indazoles bearing either electron‐withdrawing or electron‐donating substituents may be prepared.
Benzo[b]thiophene. Derivatives. XXVIII. 5‐bromo‐3‐benzo[b]thienylalanine and derivatives
Authors: Campaigne E. , Kim Chung S.
Published: April 2009

A potential inhibitor of gelation of sickle hemoglobin, 5‐bromo‐3‐benzo[b]thienylalanine, has been synthesized along with several derivatives. Several hydrolytic pathways from the intermediate ethyl 5‐bromo‐3‐benzo[b]thienylformamidomalonate have been examined, and that involving alcoholysis to ethyl N‐formyl‐5‐bromo‐3‐benzo[b]thienylalanine shown to be superior.
Polarographic reduction and tautomeric structure of 2‐amino‐5‐arylazothiazoles
Authors: Elanadouli Bahgat E. , Abdelhamid Abdou O. , Shawali Ahmad S.
Published: April 2009

The polarographic behaviour of a series of 2‐amino‐4‐phenyl‐5‐arylazothiazoles has been investigated at a dropping mercury electrode. Each of the compounds studied exhibits one wave which was shown to correspond to the reductive cleavage of the azo linkage by a 4e irreversible step. On the basis of the polarographic data, it was concluded that the compounds exist only in one tautomeric form, namely the aminoazo structure 1. The results of E1/2 — σX correlations and HMO calculations of bonding energies of the various possible tautomeric forms 1–3 indicate that the aminoazo form 1 is the most stable structure of the compounds examined.
Heterocycles of biological importance. Part 1. Novel synthesis and biological activity study of 5‐Alkyl and 5‐Aryl‐7‐aminopyrazolo[1,5‐a]‐pyrimidines from allenic or acetylenic nitriles and 3‐aminopyrazole
Authors: Fomum Z. Tanee , Asobo P. Forche , Ifeadike P. Ngozi
Published: April 2009

Allenic nitriles react with 3‐aminopyrazole in ethanol or dimethylformamide to give 5‐alkyl‐7‐aminopyrazolo[1,5‐a]pyrimidines5of pharmaceutical interest in good yields. 3‐Phenylpropynenitrile reacts with 3‐aminopyrazole in a similar manner to give the aryl compound8.
Chemistry of thienopyridines. XXXII. Direct introduction of C‐substituents gamma to the heteronitrogen atom in the thieno[2,3‐b]pyridine system
Authors: Klemm L. H. , Muchiri Daniel R. , Louris John N.
Published: April 2009

Treatment of the N‐oxide 1a of thieno[2,3‐b]pyridine (1) with either (a) acetic anhydride and ethyl cyanoacetate or (b) benzoyl chloride and an enamine of cyclohexanone (Hamana reactions) serves to introduce a C‐substituent at the 4‐position of 1. In case (a) one obtains a yellow, isolable vinylogous N‐ylide 5 (23% yield), which undergoes facile transformation into ethyl 2‐(4‐thieno[2,3‐b]pyridyl)cyanoacetate (1e) (88–93 %). Acetic anhydride reconverts 1e to 5 (95%). Case (b) produces 2‐(4‐thieno[2,3‐b]pyridyl)cyclohexanone (39%), hydrolyzable to 6‐(4‐thieno[2,3‐b]pyridyl)hexanoic acid (45%). The hydrochloride of 1a is also reported. Structural formulations are based on spectral studies (including 13C nmr data for 1 and 1e) and chemical transformations. Major contrasts (plus some similarities) between the systems 1 and quinoline in the Hamana reactions are discussed.
Shift reagent 1H NMR study of methoxycoumarins
Authors: Joseph‐Nathan P. , DomÍnguez M. , Ortega D. A.
Published: April 2009

The complete assignment of the proton chemical shifts of coumarin (1), all monomethoxy derivatives and the six possible dimethoxyl substituted compounds at the aromatic ring was achieved at 60 MHz in a quantitative study utilizing Pr(fod)3 as the shift reagent. It was found that in addition to the complexation at the lactone carbonyl a second interaction of the lanthanide shift reagent occurs when two methoxyl groups are found in an ortho distribution. The results are discussed in comparison to data published for flavones in the presence of Pr(fod)3 shift reagent.
Bromination of methyl substituted 1,2,5‐thiadiazoles with N‐bromosuccinimide
Authors: Mataka Shuntaro , Kurisu Masayoshi , Takahashi Kazufumi , Tashiro And Masashi
Published: April 2009

Bromomethyl‐1,2,5‐thiadiazoles 2a‐c were prepared by bromination of methyl‐1,2,5‐thiadiazoles 1a‐c by NBS in refluxing carbon tetrachloride. When bromination of 1a and 1b was carried out under irradiation of tungusten lamp, mixtures of cis‐5a and b and trans‐1,2‐dibromo‐1,2‐bis(1,2,5‐thiadiazol‐3‐yl)ethylene (6a and b) were obtained.
13C NMR spectra of 1‐(α‐aroyloxyarylideneamino)‐1,2,3‐triazoles. Identification of 4,5‐unsymmetrically substituted derivatives
Authors: Rodios Nestor A.
Published: April 2009

The 13C nmr spectra of the title compounds are reported. Chemical shifts of C‐4 and C‐5 carbons of the triazole ring are used for structural assignment of the 4,5‐unsymmetrically substituted 1‐(α‐aroyloxyarylideneamino)‐v‐triazoles (triazolylisoimides). A complete assignment of the shifts of the α‐aroyloxyarylideneamino group is given. Some JC‐H values are also reported.
A Convenient Synthesis of 2‐N‐Methoxycarbonylaminooxazolo[5,4‐d]pyrimidines
Authors: Chern Ji‐Wang , Wise Dean S. , Townsend Leroy B.
Published: April 2009

A facile synthesis of methyl oxazolo[5,4‐d]pyrimidine‐2‐carbamic acids by the cyclodesulfurization of a methoxycarbonyl thiourea with dicyclohexylcarbodiimide is described.
The synthesis of pyrazolo[3,4‐d]pyridazines. Photochemical cyclization to pyrazolo[3,4‐d]pyridazin‐4(5H)‐ones with subsequent functionalization
Authors: Kaji Kenji , Nagashima Hiromu , Ohta Yusho , Tabashi Keizo , Oda Hirohisa
Published: April 2009

The synthesis of 1,3‐disubstituted and 1,3,5‐trisubstituted 1H‐pyrazolo[3,4‐d]pyridazin‐4(5H)‐ones is conveniently performed by photochemical cyclization. Functionalization of the former compounds leading to the formation of 1,4‐disubstituted and 1,3,4‐trisubstituted 1H‐pyrazolo[3,4‐d]pyridazines is smoothly effected through pertinent nucleophilic substitutions.
Synthesis of 7‐substituted 1H‐indolo[3,2‐d][1,2]benzoxazepines
Authors: Klioze Sol S. , Ehrgott Frederick J. , Glamkowski Edward J.
Published: April 2009

The synthesis of the novel 7‐substituted 1H‐indolo[3,2‐d][1,2]benzoxazepine ring system is described. Fischer indolization of 2‐fluoroacetophenone phenylhydrazone provided the starting material 2‐(2‐fluorophenyl)‐1H‐indole. An acyl group was then introduced at the 3‐position of the indole nucleus and the resulting ketone was converted to the ketoxime. Upon treatment with sodium hydride to form the oxanion of the ketoxime, an intramolecular cyclization took place via displacement of fluoride from the adjacent 2‐fluorophenylsubstituent. This ring closure completed the construction of the 1H‐indolo[3,2‐d][1,2]benzoxazepine ring system.
Synthesis of 7‐azadispiro[5.1.5.2]pentadecane and 6‐azadispiro[4.1.5.2]tetradecane
Authors: Wagner E. R. , Matthews D. P.
Published: April 2009

Two new, hindered secondary amines, 7‐azadispiro[5.1.5.2]pentadecane hydrochloride (1a) and 6‐azadispiro[4.1.5.2]tetradecane hydrochloride (1b), have been prepared in four steps from 1‐ethynylcyclohexylamine (2). The final thermal cyclization of 1‐(2‐(1‐aminocyclohexyl)ethyl)cyclohexyl chloride (5a) produces 1‐(2‐(1‐aminocyclohexyl)ethyl)cyclohexene hydrochloride (6a) and an unsaturated hydrocarbon 7 in addition to 1a.
Nitrogen bridgehead compounds. Part 45 [1]. Synthesis of 6‐arylhydrazono‐6,7,8,9‐tetrahydro‐11H‐pyrido‐[2,1‐b]quinazolin‐11‐ones
Authors: Kökösi József , Szász György , Hermecz István , Podányi Benjámin , Mészáros And Zoltan
Published: April 2009

A series of 6‐arylhydrazono‐6,7,8,9‐tetrahydro‐11H‐pyrido[2,1‐b]quinazolin‐11‐ones 3–37, conveneint starting materials for indolopyridoquinazolines, were prepared by diazonium coupling between aryldiazonium chlorides and 6,7,8,9‐tetrahydro‐ 2, 6‐formyl‐5,7,8,9‐tetrahydro‐ 39, 6‐(dimethylamino)methylene‐6,7,8,9‐ 38 or 6‐carboxyl‐5,7,8,9‐tetrahydro‐11H‐pyrido[2,1‐b]quinazolin‐11‐ones 43. The arylhydrazono derivatives were also prepared from 6‐bromo‐ 45 or 6,6‐dibromo‐6,7,8,9‐tetrahydro‐11H‐pyrido[2,1‐b]quinazolines 46 with arylhydrazines. The structures of the 6‐arylhydrazonopyridoquinazolines were characterized by uv and 1H nmr spectroscopy. The 6‐arylhydrazono derivatives show a solvent‐dependent E‐Z isomerism.
5‐Cyano‐6‐aryluracil and 2‐thiouracil derivatives as potential chemotherapeutic agents. IV
Authors: Ram Vishnu J. , Berghe D. A. Vanden , Vlietinck A. J.
Published: April 2009

A series of 5‐cyano‐6‐aryluracils and 2‐thiouracils1a‐hhas been prepared and alkylated to 1,3‐dialkyluracils2a‐dand 2‐alkylthiouracils,3, 4and6, by electrophilic substitution with alkyl halides. Reaction of1bwith dibromoethane and 1,3‐dibromopropane gave the corresponding bicyclic products, 7‐aryl‐6‐cyano‐2,3‐dihydrothiazolo[3,2‐a]pyrimidin‐5‐ones5a,band 8‐aryl‐7‐cyano‐3,4‐dihydro‐2H‐pyrimido[2,3‐b][1,3]thiazin‐6‐ones5c‐g. Nucleophilic substitution on6with hydrazine led to7which on refluxing with formic acid gave 5‐aryl‐6‐cyano‐8‐methyl‐s‐triazolo[3,4‐b]pyrimidin‐7‐ones (9), while with acetic and propionic acids only 2‐acylhydrazino‐3‐methyl‐4‐oxo‐5‐cyano‐6‐arylpyrimidines8a,bwere isolated. The hydrazine7undergoes cyclization with acetylacetone and methyl dimethylmercaptoacrylate providing 2‐(pyrazol‐1‐yl)‐3‐methyl‐4‐oxo‐5‐cyano‐6‐substituted pyrimidines10, and11. Some of the compounds were screened for antibacterial‐, antifungal‐ and antiviral activities and a few of them showed significant chemotherapeutical activities.
Synthesis of 7‐(1‐pyrrolidinyl)‐1,2,4‐triazolo[4,3‐b]pyridazines
Authors: Peet Norton P.
Published: April 2009

The reactions of secondary amines (pyrrolidine, piperidine and morpholine) with 3,4,5‐trichloropyridazine (4) was investigated. With 4 and excess amine, disubstitution occurred in good yield and selectively at positions 3 and 5. Treatment of 4 with 2 equivalents of the amine in ethanol afforded high yields of products resulting from monosubstitution at position 5. 3,4‐Dichloro‐5‐(1‐pyrrolidinyl)pyridazine (6a), resulting from 4 and 2 equivalents of pyrrolidine, was converted cleanly to 4‐chloro‐3‐hydrazino‐5‐(1‐pyrrolidinyl)pyridazine (8) with hydrazine hydrate. Pyridazine 8 was cyclized with formic acid to give a 1:1 complex (9) of formic acid and 8‐chloro‐7‐(1‐pyrrolidinyl)‐1,2,4‐triazolo[4,3‐b]pyridazine (13). Triazolopyridazine 13 also formed a monohydrate (12) and a monohydrochloride salt (14). Catalytic hydrogenation of 9 gave 7‐(1‐pyrrolidinyl)‐1,2,4‐triazolo[4,3‐b]pyridazine (3), which was a target compound of this investigation.
Reactions of derivatives of anthranilic acid with 3‐chloropropyl isocyanate
Authors: Papadopoulos E. P.
Published: April 2009

The urea 1 obtained from anthranilonitrile and 3‐chloropropyl isocyanate is converted into 3‐(3‐chloropropyl)‐2,4(1H,3H)quinazolinedione (4) when heated with hydrochloric acid, whereas it undergoes a double cyclization to form 2,3,4,7‐tetrahydro‐6H‐pyrimido[1,2‐c]quinazolin‐6‐one (3) upon heating, or treatment with ammonia. On the other hand, the urea 5 formed from methyl anthranilate and 3‐chloropropyl isocyanate cyclizes in three different ways, when treated with ammonia, potassium bicarbonate, or concentrated sulfuric acid, to yield compound 4, 3,4‐dihydro‐2H,6H‐[1,3]oxazino[2,3‐b]quinazolin‐6‐one (9), or 2‐[(3‐chloropropyl)amino]‐4H‐3,1‐benzoxazin‐4‐one (6), respectively. Acid‐catalyzed reactions of compound 9 with nucleophilic reagents proceed with opening of the oxazine ring and readily yield various 3‐substituted 2,4(1H,3H)‐quinazolinediones.
Radical cation formation and crystal structure determination of 4′‐dimethylamino‐10‐phenylpyrido[3,2‐b]benzothiazine
Authors: Jovanovic Misa V. , Biehl Edward R. , De Meester Patrice , Chu Shirley S. C.
Published: April 2009

The crystal structure of title compound, 4, shows that the 10‐aryl group is parallel to the plane bisecting the pyridobenzothiazine ring. This structure is in contrast to that normally found for phenothiazines substituted with electron‐withdrawing substituents on the 10‐phenyl ring. In those compounds, the 10‐aryl group is perpendicular to the plane bisecting the phenothiazine ring. The esr spectrum of the cation radical of 4 shows that the radical is located on the hetero ring system which is opposite to that of the cation radical of 4′‐dimethylamino‐10‐phenylphenothiazine in which the radical is located on the 10‐aryl ring.
Pyrrolothienopyrazines: étude chimique de la pyrrolo[1,2‐a]‐thiéno[3,2‐e]pyrazine
Authors: Rioult Jean‐Philippe , De Sévricourt Michel Cugnon , Rault Sylvain , Robba Max
Published: April 2009

La réactivité de la pyrrolo[1,2‐a]thiéno[3,2‐e]pyrazine 1 est étudiée vis‐à‐vis des réactions de quaternarisation, bromation, nitration, Friedel Crafts, Vilsmeier Haack, sulfonation et de Reissert. La structure des produits obtenus est déduite de l'analyse de leur spectre de rmn ou de masse. Les mélanges ont été étudiés par chromatographie en phase gazeuse couplée à la spectrométrie de masse (gc/ms).