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HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 26, No. 8, 1987
Published online:
■ On the Aromatic Stability of Azulenofurans, Azulenopyrroles and Azulenothiophenes
Sonja Nikolic, Albin Juric, and Nenad Trinajstic
*Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, U.S.A.
Abstract
The aromatic stabilities of isomeric azulenofurans, azulenopyrroles and azulenothiophenes have been studied by three theoretical models of aromaticity: the graphical model, the conjugated circuits model and the topological resonance energy model. All three models predict that molecules with the delocalized underlying carbon structure are more stable than those with the quinoid structure. In each class of positional isomers, azulenopyrroles are always predicted to be more stable than the correspending isomeric azulenothiophenes, and these more stable than the corresponding azulenofurans. However, all azulenofurans, azulenopyrroles and azulenothiophenes are predicted to be less aromatic than the parent hydrocarbon 2,3-benzazulene. It is suggested that the differences in stability between azulenofurans, azulenopyrroles and azulenothiophenes is related to the differences in stability between the heterocyclic parts of the molecules, i.e. furan, pyrrole and thiophene, since the carbon parts are identical.
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■ A Rigid Conformation for 5-Fluoro-2,11-dithia[3.3](1,4)naphthalenometacyclophane with Absence of Meta-ring Flipping
Yee-Hing Lai and Thian-Guan Peck
*Department of Chemistry, National University of Singapore, 10 Kent Ridgh Crescent, 119260, Singapore
Abstract
19F and 1H nmr data suggest the presence of only one major isomer for the title compound with the unexpected stacking of the benzene and naphthalene rings. Variable temperature 1H nmr studies suggested no meta-ring flipping even at 160°C. The chemical shifts of the methylene protons were observed to be solvent and temperature dependent. This is attributed to the solvent effects on inversion processes of the bridges.
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■ Structural Studies on the Isomers of Triply Bridged Ring Substituted Difluorotrithiacyclophanes Using 1H and 19F Nmr Spectroscopy
Yee-Hing Lai and Thian-Guan Peck
*Department of Chemistry, National University of Singapore, 10 Kent Ridgh Crescent, 119260, Singapore
Abstract
The isomeric 5,16- and 7,16-difluoro-2,11,20-trithia[3.3.3]-(1,3,5)cyclophanes were obtained in good yields from a single coupling reaction. Their structureswere readily characterized by 1H nmr studies. Comparison of the 19F nmr data helps to suggest a possible ring staggered conformation for the reported 9,18-difluoro-2,11-dirhia[3.3]metacyclophene.
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■ Synthesis of (±)-2β,20-Epoxy-12-methoxyabieta-8,11,13-trien
Ajoy K. Banerjee, Julio C. Acevedo, and Jaime Alvárez G.
*Centro de Química, Instituto Venezolano de Investigaciones Científicas, I.V.I.C., Apartado 21827, Caracas 1020-A, Venezuela
Abstract
The synthesis of the titled compound (1) and its conversion to pisiferic acid (2) are described.
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■ A Reinvestigation of the Reaction of N-(2-Bromoethyl)isatoic Anhydride with methylamine. Isolation and Crystal Structure of 1-(2-Hydroxyethyl)-3-meethyl-2,4-(1H,3H)-quinazolinedione
Francesco Pinnen, Gino Lucente, Fernando Mazza, and Giorgio Pochetti
*Dipartrimento di Chimica, Instituto di Farmacologia Medica, Università degli Studi di Roma, "La Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy
Abstract
The reaction of N-(2-bromoethyl)isatoic anhydride with methylamine affords 1-(2-hydroxyethyl)-3-methy1-2,4-(1H,3H)-quinazolinedione, the structure of which has been determined by single crystal X-ray diffraction.
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■ Four New Acridone Alkaloids from Sarcomelicope dogniensis Hartley (Rutaceae)
Sofia Mitaku, Alexios-Leandros Skaltsounis, François Tillequin, Michel Koch, Jacques Pusset, and Gérard Chauvière
*U.A. au C.N.R.S.n°484, Faculté des Sciences Pharmaceutiques et Biologiques, Université René Descartes, 4, Avenue de l’Observatoire, F-75006 Paris, France
Abstract
Four new acridone alkaloids, 1, 3, 4 and 6 have been isolated from the leaves of Sarcomelicope dogniensis. Their structures have been elucidated by spectroscopic studies and confirmed by their synthesis, using N-desmethylacronycine (2) as starting material.
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■ Regiospecific Amination of 3-Substituted Pyridines Using Imidoyl Chloride Functionalized Polystyrene
Rudolph A. Abramovitch and Wang You-Xiong
*Department of Chemistry, Clemson University, Clemson, SC 29631, U.S.A.
Abstract
New imidoyl chloride functionalized polystyrenes have been prepared and reacted with pyridine 1-oxides; regiospecific acylamination of 3-substituted pyridines at the 6-position has been achieved, the corresponding aminopyridine obtained by hydrolysis and, the polymer reagent recycled.
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■ The Synthesis of Heptenic Derivatives of Aminoimidazoazaarene Cooked-food Mutagens
Bruce E. Watkins, Mark G. Knize, Chunk J. Morris, Brian D. Andresen, James Happe, Martin Vanderlaan, and James S. Felton
*Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, P.O.Box 5507. L-452, Livermore, California 94550, U.S.A.
Abstract
2-N-Aminopropyl derivatives of the food mutagens IQ, MelQx and PhlP were synthesized along with 3-(2-amino-3-methylimidazo[4,5-f]quinoxalin-8-yl) propionic acid. These were used as haptens for the production of monoclonal anlibodies.
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■ The Effect of Benzannelation toward Cycl[3.2.2]azine. Synthesis and Physical Properties of Dibenzo[a,h]cycl[3.2.2]azine
Yoshinori Tominaga, Yoshihide Shiroshita, Yoshiro Matsuda, and Akira Hosomi
*Faculty of Pharmaceutical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan
Abstract
Dibenzo[a,h]cycl[3.2.2]azine (2) was synthesized by the [2 + 8] cyclization reaction of 1-cyanoisoindolo[2,1-a]isoquinoline (6) with dimethyl acetylenedicarboxylate as a key step and the effect of dibenzo-annelation on the six- and five-membered ring parts of the cyc1[3.2.2]azine has been investigated.
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■ Junosidine: A New Linear Pyranoacridone Alkaloid from Citrus junos Tanaka
Motoharu Ju-ichi, Mami Inoue, Kayo Sakiyama, Mayumi Yoneda, and Hiroshi Furukawa
*Faculty of Pharmaceutical Science, Mukogawa-Women‘s University, 11-68 Koushien Kyuban-Cho, Nishinomiya, Hyogo 663-8179, Japan
Abstract
From the root bark of Citrus junos Tanaka, a new acridone alkaloid, junosidine (1), was isolated and its structure was elucidated on the basis of spectral data.
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■ A New Rearrangement of α-Azo Alcohols into N-Substitutes Bridged Bicyclic Lactams. A Possible Model for Conformation-dependent Rearrangement
Takahi Otsuka and Takahiro Tezuka
*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan
Abstract
A new thermal rearrangement of sterically crowded α-azo alcohols (2 and 4) into bridged bicyclic lactams (9 and 11) is reported. A mechanism for this rearrangement is proposed.
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■ A New Route to (Z)-3-Alkylidene-(S)-6-alkyl-2,5-piperazinediones via N-Carboxy-α-dehydroamino Acid Anhydrides
Chung-gi Shin, Yasuchika Yonezawa, and Kazumichi Ogawa
*Departmnet of Applied Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
Abstract
A new synthetic method for (Z)-3-alkylidene-(S)-6-alkyl-2,5-piperazinediones was accomplished by the coupling of N-carboxy-α-dehydroamino acid anhydrides with Boc-α-amino acid, followed by the deprotection of Boc group and by the ring expansion.
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■ Ring Transformation of Pterins to Guanines
Takashi Sugimoto, Noriko Nishioka, Shizuaki Murata, and Sadao Matsuura
*Human Informatics, Graduate of School, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
Abstract
7-Alkoxypterins undergo a ring contraction into guanine derivatives and demethoxylation by activated aluminum.
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■ Periplosides A, B and C, Steroidal Glycosidesof Periploca sepium Root-barks
Yoshiteru Oshima, Toshiyuki Hirota, and Hiroshi Hikino
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Three new steroidal glycosides, periplosides A, B and C, among which periploside A exhibited anticomplementary activity, have been lsolated from Periploca sepium root-barks. The structures of periplosides A, B and C have been elucidated as shown in formulas 1, 2 and 3, respectively, on the basis of chemical and spectroscopic evidence.
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■ Synthesis of (±)-Roemecarine and (±)-Epiroemecarine: Revised Stereostructure for (+)-Roemecarine
Osamu Hoshino, Katsuhiko Itoh, Bunsuke Umezawa, Hiroyuki Akita, and Takeshi Oishi
*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
Abstract
(±)-Roemecarine (1) and (±)-epiroemecarine (2) were synthesized from (±) -1,4-trans- and (±)-1, 4-cis-4-acetoxy-1-benzyltetrahydroisoquinolin-6-ols (3 and 4). The present synthesis revealed that stereostructure of (+)-roemecarine was 1.
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■ A Novel Synthesis of Pyridazinones: Preparation of 3-[1-Aryl-6(1H)-pyridazinon-3-yl]-2(1H)-quinoxalinones
El Sayed H. El Ashry, Yeldez El Kilany, and Adel Amer
*Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt
Abstract
A novel approach for the synthesis of pyridazinones has been achieved by the reaction of α-formylhydrazones with carboethoxymethylidene triphenylphosphorane. The mode of the reaction was investigated and the structures were confirmed by both physical and chemical methods. Thus, 3- [1-aryl-6(1H)-pyridazinon-3-yl]-2(1H-quinoxalinon(19) were prepared.
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■ Synthesis of a Cyclic Octapeptide
Toyoshi Katagi and Hiromi Kataoka
*School of Pharmaceutical Science, Mukogawa University, Edogwa-cho, Nishinomiya, Hyogo 663, Japan
Abstract
The cyclic octapeptide cyclo-((L-Lys(Z))2-Gly-(L-phe)2-(Gly)3) (13) was synthesized as an ionophore model. And transport of L-Phe-OMe.HCl through an organic liquid membrane mediated by (13) is reported.
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■ Reaction of Potassium Superoxide with 3-Nitro-2-phenyl-2H-1-benzopyrans and Their Dihydro Derivatives
Takkellapati Sudhakar Rao and Girish Kumar Trivedi
*Department of Chemistry, Indian Institute of Technology, Powai, Bombay 400 076, India
Abstract
3-Nitro-2-phenyl-2H-l-benzopyrans on treatment with potassium superoxide in dimethyl sulphoxide are degraded mainly to the corresponding salicylic acids and benzoic acids. Formation of flavonols, as a minor product are also observed. The dihydro derivatives of 3-nitro-2-phenyl-2H-1-benzopyrans are converted to the corresponding flavonols by potassium superoxide in benzene containing 18-crown-6 ether.
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■ Strictine — A New Mavacurine Type Alkaloid from the Leaves or Rhazya stricta
Atta-ur-Rahman and Sajida Khanum
*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
A new alkaloid strictine (1) has been isolated from the leaves of R.stricta. The structure has been confirmed by 13C-NMR studies and 1H-NMR homodecoupling experiments.
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■ 2-Aminoehtylimidazoles. Synthesis of 1,4-Dimethyl-5-phenyl-2-[2-(4-phenylpiperazinyl)ethyl]imidazole
Emilio Toja, Pietro Ferrari, and Giorgio Tarazia
*Lepetit Research Center, via R. Lepetit, 34-21040 Gerenzano (VA), Italy
Abstract
A novel synthesis of N1-methyl-1-phenyl-1,2-propanediamine (9) from 2-benzylamino-1-phenylpropanone (3) is reported. Condensation of this diamine with ethyl ethoxycarbonylacetimidate hydrochloride and dehydrogenation of the resulting imidarolidine (10) gives ethyl 2-(1,4-dimethyl-5-phenylimidazol-2-yl)metate (11), suitable starting material for the synthesis of imidazoles with a 2-aminoethyl chain. The synthesis of the 2-[2-(4-phenylpiperazinyl)ethyl] derivative 14 is specifically reported.
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■ α-Alkyltryptohans
Miguel F. Braña, Mercedes Garrido, María L. López Rodríguez, and M. José Morcillo
*Departamento de Química Orgánica I., Facultad de Química, Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
A study of three direct methods for the synthesis of α-alkyl α-amino acids has been applied to the preparation of α-alkyltryptophan esters. Reaction of Nb-benzylidene-L -tryptophan methyl esters 3 with tetrabutyl-ammonium hydrogen sulfate and methyl or ethyl iodide (phase-transfer method) gives α-methyl and α-ethyltryptophan methyl esters 6a,b in poor yield with complete racemization. Reaction of L-tryptophan 1 with dimethylformamide dimethyl or diethyl acetal followed by treatment of 8a,b with LDA and methyl iodide (Fitt and Gschwend method) gives rise to the formation of α,Na -dimethyl-Nb - dimethylsminamethylenetryptophan methyl or ethyl esters hydriodide 9 a,b . Treatment of 9a or 9b with aqueous acid, under mild conditions, fails to hydrolyze the imine functionality. Reaction of 3 with LDA and methyl or ethyl iodide (Bey and Vevert method) followed by hydrolysis provides α-methyl and α-ethyltryptophan methyl esters 6a,b. By carrying out this procedure with isopropyl, benzyl and allyl iodide or bromide the corresponding α-alkyl esters are not obtained.
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■ New Synthesis of 1,2,5-Selenadiazoles
Vincenzo Bertini, Angela De Munno, Nevio Picci, Francesco Lucchesini, and Marco Pocci
*Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgnimento 35, I-56126 Pisa, Italy
Abstract
A new synthesis of 1,2,5-selenadiaroles which starts from unsubstituted or monosubstituted 1,2,5-thiadiazoles and Grignard reagents is described and the mechanism of the reaction discussed.
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■ Synthesis of Substituted 3-Pyridinecarboxaldehydes
Daniel L. Comins and James J. Herrick
*Department of Chemistry abd Biochemistry, Utah State University, Logan, Utah 84332-0300, U.S.A.
Abstract
Treatment of 3-substituted 1-(phenoxycarbony1)-1,2-dihydropyridines with Vilsmeier reagent (POCl3/DMF) gave 3-substituted 5-fomyl-1- (phenoxycarbonyl)-1,2-dihydropyridines, which were aromatized with hot sulfur to provide 5-substituted 3-pyridinecarboxaldehydes. The formylation of 4-substituted 1-(phenoxycarbony1)-1,4-dihydropyridines and subsequent armatization gave 4-substituted 3-pyridinecarboxaldehydes.
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■ A Stereoselective Synthesis of cis-4-Acetonyl-1-benzyl-3-ethylpiperidine
Josep Bonjoch, Ana Linares, Manel Guardià, and Joan Bosch
*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain
Abstract
The title compound cis-1, a potential synthon for indole alkaloid synthesis, is prepared for the first time. The synthesis starts with the condensation of 3-ethyl-4-piperidone 2 with triethyl phosphonoacetate followed by stereoselective hydrogenation of the resulting α,β-unsaturated ester 5 to give 4-piperidineacetate cis - 6 as the major isomer. This was converted in high yield to the target molecule cis-1 by a two-step sequence through the corresponding β-keto sulfoxide cis-7.
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■ Intermolecular Cycloaddition Reactions of Exocyclic Nitrones. Facile Synthesis of 1-Azaspirocycles
Raymond L. Funk and Joy Umstead Daggett
*Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebrasa 68588, U.S.A.
Abstract
A two step procedure for transforming cycloaikanones via intermediate exocyclic nitrones to 1-azaspirocycles is described.
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■ Synthesis of Bridgehead-nitrogen Heterocycles from Pyrylium Salts: Preparation of the Novel Tricyclic Thiazolo[2,3-a]pyrido[2,1-f][1,2,4]triazine Ring System
Pedro Molina, Alberto Tárraga, Mercedes Lorenzo-Peña, and Arturo Espinosa
*Departmento de Química Orgánica, Facultad de Ciencias, Universidad de Murcia, 30071 Murcia, Spain
Abstract
A number of thiazolo[2,3-c]pyrido[2,1-f][1,2,4]triazine derivatives have been prepared by reaction of the 4-oxo-6,8-diphenyl- 3,4-dihydropyrid0[2,1-f][1,2,4]triazin-9-ium-2-thiolate, available from 2-ethoxycarbonyl-4,6-diphenylpyrylium cation and thiosemicarbazide, with phenacyl bromides and subsequent cyclization by the action of acetic anhydride.
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■ Synthesis of Novel 7,7’-Bis-6a,7-dehydronoraporphines
Akino Jossang, Michel Lebœuf, and André Cavé
*Laboratoire de Pharmacognosie, URA 1843 CNRS(BIOCIS), Faculte de Pharmacie, Université Paris XI, 92296 Chatenay-Malabry Cedex, France
Abstract
New dimers, (±)-bisdehydroanonaine 5a, (±)-bisdehydroxylopine 5c, (±)-bisdehydronornantenine 5d and (±)-7-dehydroxyiopinyl-7’-dehydronornantenine 8, and the previously described (±)-urabaine 5b, were prepared from dehydroxyiopine 3c and known dehydronoraporphines 3a, 3b, and 3d via dimerization at the β-carbon of cyclic secondary enamines.
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■ Heterocycles from Nitrile Oxides. Part IV. 1,2,4,5-Oxatriazines
Ahmad Q. Hussein, Mustafa M. El-Abadelah, Hamadallah A. Hodali, Marwan R. Kamal, and Mohammed M. Aouf
*Chemistry Department, Faculty of Science, University of Jordan, Amman 11942, Jordan
Abstract
The reaction of nitrile oxides with hydrazones is found to constitute a convenient synthetic route to the hitherto unknown 4,5-dihydro-6H-1,2,4,5-oxatriazines. Elemental analysis and spectral data conform with the present oxatriazine ring system and disprove the 1,2,4-triazole structure previously assigned for such reaction products.
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■ 1-Phenethyl-2,3,4,5-tetrahydro-1H-2-benzazepines from 2-Acetyl-1-methylene-2,3,4,5-tetrahydro-1H-2-benzazepines
Ricardo Alomso and Arnold Brossi
*Section of Medical Chemistry, Laboratory of Analytical Chemistry, NIDDK, National Institute of Health, Bethesda, MD 20982, U.S.A.
Abstract
(±)-1-(3’,4’,5’-Trimethoxyphenethyl)-7,8-dimethoxy-2,3,4,5-tetrehydro-1H-2-benzarepine (7) and its N-acetyl derivative 8, of which the 1-phenyl analogs have potent platelet antiaggregatory properties, have been synthesized from 2-acetyl-1-methylene-7,8-dimethoxy-2,3,4,5-tetrahydro-1H-2-benzazepine (1). The chemical reactivity of 2-benzazepines in this transformation has shown to be very similar to that of isoquinolines.
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■ Reactions of Elemental Sulfur and Selenium with Some Asetylenic Compounds. Formation of Thiophenes and Selemophenes
Juzo Nakayama, Rie Yomoda, and Masamatsu Hoshino
*Department of Chemistry, Faculty of Science, Saitama University, Saitama, Saitama 338-8570, Japan
Abstract
The reaction o f 3-butyn-2-one with elemental sulfur at 205-215 °C in benzene in a stainless autoclave afforded 2,4- and 2,5-diacetylthiophenes in 43% and 22% yields, respectively. Under similar conditions, the reaction with elemental selenium gave 2,4-and 2,5-diacetylselenophenes in 32% and 29% yields, respectively. Diphenylacetylene reacted with sulfur and selenium to produce tetraphenylthiophene (78%) and tetraphenylselenophene (38%, respectively. The reaction of di(2-thienyl)acetylene with sulfur provided tetra(2-thienyl)thiophene in 57% yield. The reaction of dimethyl acetylenedicarboxylate with sulfur in the presence of diphenylacetylene afforded 2,3-bis(methoxycarbonyl)-4,5-diphenylthiophene (29%) and tetrakis(methoxycarbonyl)thiophene (15%). On the basis of these results, the mechanism for the formation of thiophenes and selenophenes is disccused.