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. 45, No. 12, 1997
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■ Novel Syntheses of Optically Active CC-1065, U-73,975(Adozelesin), U-80,244(Carzelesin), U-77,779 (Bizelesin), KW-2189, and DU-86
Yasumichi Fukuda,* Hirosuke Furuta, Futoshi Shiga, Yoshikazu Asahina, and Shiro Terashima*
*Central Research Laboratories, Kyorin Pharmaceutical Co. Ltd., Mitarai, Nogi, Tochigi 329-0114, Japan
Abstract
The title syntheses were achieved by the method featuring oxidative cyclization of the enamino esters [(S)-13 and (S)-24] derived from the 5-aminoindoline [(S)-12], acylation with various structural types of indole-2-carboxylic acids, and formation of cyclopropapyrroloindole moieties.
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■ The Use of the N-Substituted Triethyl(indol-2-yl)borate for the Palladium Catalyzed Cross-Coupling Reaction
Minoru Ishikura,* Yukinori Matsuzaki, and Isao Agata*
*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
Abstract
The influence of N-substituent of triethyl(indol-2-yl)borate (2) on the palladium catalyzed cross-coupling reaction was examined, and an efficiency of triethyl(1-tert-butoxycarbonylindol-2-yl)borate (2e) could be shown.
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■ Stereoselectivity in the Formation of 2,5-Disubstituted Tetrahydropyrans by Intramolecular Hetero-Michael Addition
Ryukichi Takagi, Asami Sasaoka, Satoshi Kojima, and Katsuo Ohkata*
*Department of Chemistry, Faculty of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526, Japan
Abstract
A stereoselective formation of tetrahydropyran ring having acrylate moiety at C2 and geranyl or homofarnesyl group at C5 based on intramolecular hetero-Michael addition is described.
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■ The Novel Preparation Methods of 5-Substituted Methyl-1-azabicyclo-[3.3.0]octane
Mitsuru Oka, Kunihisa Baba, Tomoo Suzuki, and Yukiharu Matsumoto*
*Drug Discovery Research Department, Sanwa Kagaku Kenkyusho, 363 shiosaki, Hokusei-cho, Inabe-gun, Mie, 511-04, Japan
Abstract
5-Substituted methyl-1-azabicyclo[3.3.0]octane, which is a useful intermediate for drugs, was readily synthesized from 1,7-dichloro-4-heptanone without isolating unstable intermediates.
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■ Efficient Synthesis of a New Aminoazasugar and Dihydroxyprolines from an Endocyclic Enecarbamate
Adrian M. Pohlit and Carlos Roque D. Correia*
*Instituto de Química, Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6154, CEP 13083-970, Campinas, Sao Paulo, Brazil
Abstract
A novel procedure for the synthesis of trans-2,3-(2-aminomethyl)-cis-3,4-dihydroxypyrrolidine (a new aminoazasugar) and cis-2,3- and trans-2,3-cis-3,4-dihydroxyprolines is presented. Starting from the known endocyclic enecarbamate 1-carbobenzyloxy-2-pyrroline, the above compounds were efficiently synthesized in 6 or 7 steps in good overall yields. In the key step, trans-2,3-(1-carbobenzyloxy)-cis-3,4-diacetyloxy-2-methoxypyrrolidine underwent Lewis acid promoted cyanation, presumably via the corresponding N-acyliminium ion.
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■ A Novel Synthetic Method of Pyrrolo[2,3-b]indoles and Its Application to the Synthesis of (±)-Debromoflustramine B
Masanori Somei,* Fumio Yamada, Tomoyuki Izumi, and Masahiro Nakajou
*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan
Abstract
1-Methoxy-3-(2-nitrovinyl)indole (4) functions as an electrophile and reacted with various nucleophiles regioselectively at the 2-position. Employing allyl alkoxides as nucleophiles, a novel synthetic method of pyrrolo[2,3-b]indoles has been elaborated. Utilizing the mothod, the synthesis of (±)-debromoflustramine B (10b) was achieved.
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■ Synthesis of Novel Tryptamine and Azepinoindole Derivatives
Lajos Novák,* Michel Hanania, Péter Kovács, János Rohály, Pál Kolonits, and Csaba Szántay
*Institute of Inorganic Chemistry, Technical University of Budapest, Gellért tér 4, H-1521 Budapest, Hungary
Abstract
A novel one-pot synthesis of azepinoindoles (9) via reaction of tryptamines (4) with formaldehyde is described. The scope and generality of this new procedure and the preparation of the starting compounds are also discussed.
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■ The Synthesis and Transformations of Methyl 2-[2,2-Bis(ethoxycarbonyl)-ethenyl]amino-3-dimethylaminobut-2-enoate. The Synthesis of 3-Amino-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones
Lovro Selic, Simona Golic Grdadolnik, and Branko Stanovnik*
*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, P.O. Box 537, SLO-1000 Ljubljana, Slovenia
Abstract
Methyl 2-[2,2-bis(ethoxycarbonyl)ethenyl]amino-3-dimethylaminobut-2-enoate (3) was prepared from methyl N-2,2-bis(ethoxycarbonyl)vinylglycinate (2) and DMADMA, and used as a reagent for the preparation of substituted 3-amino-2-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidines (13-17), 4H-benzothiazolo[3,2-a]pyrimidin-4-one (18), 5H-thiazolo[3,2-a]pyrimidin-5-one (19), and 4-methyl-tetrahydro-2H-1-benzopyran-2-ones (20) and (21).
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■ Addition of Propargyltrimethylsilane to N-Methyleneamine Equivalents: Generation and Electrophilic Cyclization of Vinylic Carbocations
Hyun-Joon Ha,* Young-Seong Lee, and Young-Gil Ahn
*Department of Chemistry, Hankuk University of Foreign Studies, Yongin, Kyunggi-Do, 449-791, Korea
Abstract
Lewis acid induced N-methyleneamine equivalents from N-(methoxymethyl)anilines or 1,3,5-triphenylhexahydro-1,3,5-triazines reacted with propargyltrimethylsilanes to give N-buta-2,3-dienylanilines, 4-methylene-1,2,3,4-tetrahydroquinolines and its oxidized product of 4-methylquinolines. These products came from branching reactions of the elimination and electrophilic aromatic substitution from the same vinylic carbocation intermediate.
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■ Synthesis and Complexation Behavior of N,N'-Bis(1-naphthylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane
Kanji Kubo,* Ryoichi Ishige, Nobuo Kato, Emi Yamamoto, and Tadamitsu Sakurai
*Department of Applied Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
Abstract
N,N’-Bis(1-naphthylmethyl)-4,13-diaza-18-crown-6 ether (2) gave intramolecular exciplex fluorescence, showing that the excited naphthalene chromophore was quenched by the azacrown unit. The azacrown ether (2) was found to display unique photophysical properties in the presence of metal salts. Complexation of 2 with Ba2+ increased the fluorescence intensity of the host by a factor of 40. 1H and 13C NMR analyses of this 1:1 complexation behavior revealed that Ba2+ strongly coordinates with the azacrown nitrogen to cause a dramatic decrease in an intramolecular charge-transfer character. In addition, it was suggested that not only the metal ion-dependent coordinated structure of the resulting complex but also the exchange rate between the free host (2) and its complex with metal ions play a role in controlling the extent of the emission-intensity enhancement that was observed in the presence of a given metal ion.
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■ Low-Valent Titanium Induced Reductive Cyclization of Isothiocyanates to Indole Derivatives
Jing Li, Da-qing Shi, and Wei-xing Chen*
*Deaprtment of Chemistry, Nanjing University, Nanjing 210093, China
Abstract
Reductive cyclization of aryl isothiocyanates (1) induced by titanium tetrachloride - zinc provides a synthesis of substituted indol-2-carbothioamides (2).
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■ Pyridazines, 85. On the Regioselectivity of Attack of O-Nucleophiles at 4-Substituted 3,6-Dichloropyridazines
Gottfried Heinisch, Barbara Matuszczak,* and Jens C. Wilke
*Institute of Pharmaceutical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
Abstract
The influence of reaction parameters on the regioselectivity of substitution of a chloro function in 3,6-dichloro-N-methyl-N-phenylpyridazine-4-carboxamide by an alkoxy group was studied. It is shown that by choosing appropriate conditions, the attack of the nucleophile can be directed either to C-3 or C-6, thus providing convenient access to both series of alkoxychloropyridazines and their dehalogenated congeners.
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■ Palladium Catalysed Coupling of Iodoquinolines and Acetylenes – A Novel Entry to the Pyrrolo[3,2,1-ij]quinoline Nucleus
Peter Blurton, Angela Brickwood, and Dashyant Dhanak*
*SmithKline Beecham Pharmaceuticals - UP1105, 1250 South Collegeville Road, Collegeville, PA 19426-0989, Denmark
Abstract
Treatment of 4-arylamino-8-iodoquinoline derivatives with propargyl alcohol and triethylamine in the presence of iodo(phenyl)bis(triphenylphosphine) palladium and copper (I) iodide gives 6-imino-substituted pyrrolo[3,2,1-ij]quinolines under mild conditions and in moderate yields. Catalytic hydrogenation over Lindlar’s catalyst affords functionalised 4H-pyrrolo[3,2,1-ij]quinolines in good yield.
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■ New Route to 7a-Angularly Substituted Hydroindoles
Kunihiko Mohri,* Yuki Yoshida, Shin-ichiro Mataga, Yohko Hisatsune, Kimiaki Isobe, and Yoshisuke Tsuda
*Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan
Abstract
Strecker type reaction of ethyl 2-oxocyclohexaneacetate with sodium cyanide and ammonium acetate gave 7a-cyano-octahydro-cis-1H-indol-2-one (2a) as a single product, which was alkylated to the N-alkyl derivatives. The cyano group in 2a was convertible to ethoxycarbonylmethyl group by reaction with the Reformatsky reagent generated from ethyl bromoacetate. In the case of the N-methyl derivative 2b, the cyano group was transformed into ethoxycarbonylacetyl group under the same reaction conditions.
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■ A Facile General Synthesis of 9-Position Functionalised Heteroniumanthracene Salts
Alan R. Katritzky,* Sergey N. Denisenko, and Peter Czerney
*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, U.S.A.
Abstract
Heteroniumanthracenes react selectively as the cations (1a) or as the corresponding carbinol bases (9a,c) with benzotriazole to give the corresponding 9H-(benzotriazol-1-yl)heterocycles (10a-c). As novel heterocyclic anion precursors, (10a-c) undergo smooth lithiations at the positions α to the benzotriazol-1-yl function, corresponding to the 9-position of the heterocycles (1a) and (9b,c). Subsequent trapping of the benzotriazolyl stabilised carbanions (11a-c) with various long chain alkyl halides forms intermediates of type (12b) which are converted by treatment with mineral acid, into the corresponding 9-functionalised heteroniumanthracene salts (13-16) (or their free bases (17-19)) in good to excellent yields.
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■ A Convenient Approach to Pentagonal 2,3':5',2"-Triheterocyclic Compounds
Ainhoa Rámila, Joaquín Plumet,* and Emilio Camacho
*Universidad Complutense de Madridas, Facultad de Química, Departamento de Química Orgánica I, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
A convenient synthesis of pentagonal 2,3’:5’,2”-triheterocyclic compounds has been achieved using as key step the conjugate addition of 2-lithio-1,3-dithiane to 1,3-bis heterocylic propenones.
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■ Fluorescent Symmetric Phenazines from Naphthoquinones
Antonio V. Pinto,* Cleverson N. Pinto, Maria do Carmo F. R. Pinto, Flavio S. Emery, Kelly C. G. de Moura, Carlos Eduardo M. Carvalho, and Ira M. Brinn
*Nucleo de Pesquisasa de Productos Naturais, Universidade Federal do Rio de Janeiro, P. O. Box 68035, Rio de Janeiro 21944-970, Brazil
Abstract
Three New symmetric phenaziens from the reaction of naphthoquinones with glycine are characterized spectroscopically. These compounds exhibit high fluorescence emission of potential use to photophysic studies.
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■ Stereoselective Synthesis of a 2,3-Disubstituted 5-Pyrrolidinone Derivative of Quinazolin-4(3H)-one
Mónika Szabó, József Kökösi,* Attila Kovács, Zsolt Böcskei, and István Hermecz
*R & D Directorate Preclinical Development, CHINOIN Pharmaceutical and Chemical Works Ltd., P. O. Box 110, H-1325 Budapest, Hungary
Abstract
Thermal cyclization of acetoacetamide (3), prepared from 2[1’-(p-methoxyphenylaminoethyl]quinazolin-4(3H)-one (2) and ethyl acetoacetate, resulted in the formation of 2-(5-oxopyrrolidin-2-yl)quinazolin-4(3H)-one (6) with high selectively in excellent yield. The stereostructure of 6 was investigated by NMR spectroscopy, and determined by X-Ray investigations.
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■ Correlation of 13C- and 15N-NMR Chemical Shifts of Ylidic Carbon and Nitrogen with Calculated Partial Charges in Pyridinium Dicyanomethylides
Kiyoshi Matsumoto,* Hideki Katsura, Takane Uchida, Kinuyo Aoyama, and Takahisa Machiguchi
*Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
Abstract
Good correlations were found between the 13C- and 15N-NMR chemical shifts of ylidic carbon and nitrogen and their partial charges, obtained by different semiempirical molecular orbital (MO) methods, of some-4-substituted pyridinium dicyanomethylides.
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■ Syntheses in the Series of Pyrazolyl-substituted Quinoxalines
Barbara Matuszczak* and Kurt Mereiter
*Institute of Pharmaceutical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
Abstract
Starting from 3-(3-chloro-1H-pyrazol-5-yl)-1H-quinoxalin-2-one (2), a dihydroquinoxalinone derivative (6) was synthesised as potential HIV-1 reverse trans-criptase inhibitor. Moreover, a series of N4-[3-(3-pyrazolyl)-2-quinoxalinyl]-N1,N1-diethyl-1,4-pentanediamines (compounds of type B) and N-[3-(3-pyrazolyl)-2-quinoxalinyl]-N-(3-pyridyl)methylamines (11-13) — structurally related to antimalarial agents — could be prepared via the 2-chloro-3-[3(5)-chloro-1H-pyrazol-5(3)-yl]quinoxaline (7). The position of the alkyl substituent on the pyrazole nitrogen was determined unequivocally from NOE difference experiments or X-Ray structure analysis.
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■ The Synthesis of Pyrido[3,2-a]acridines
Paul W. Groundwater* and Munawar Ali Munawar
*School of Health Sciences, University of Sunderland, Wharncliffe Street, Sunderland SR2 3SD, U.K.
Abstract
6-Aminoquinoline (5) reacts with 2-cyanocyclohexanone (6a) or ethyl 2-oxocyclohexanecarboxylate (6b) to give enamines which can be cyclised, under Lewis acid catalysed conditions, to tetrahydropyrido[3,2-a]acridines (9, 13). Dehydrogenation of these tetrahydropyrido[3,2-a]acridines, with palladium-on-charcoal, gives the fully aromatic pyrido[3,2-a]acridines (1a,b).
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■ A New Method for the Synthesis of 5- and 6-Membered 2-Thioxo-1,3-O,N-heterocycles
Ge Li* and Takahito Ohtani
*Fukui Research Laboratory, Rengo co., Ltd., 10-8-1 Jiyugaoka Kanazu-Cho, Sakai-Gun, Fukui 919-06, Japan
Abstract
Various 1,3-oxazolidine-2-thiones and tetrahydro-1,3-oxazine-2-thiones are prepared by reacting hydrogen peroxide with a mixture of amino alcohols, carbon disulfide and base in a water-miscible oragnic solvent. The yields of the heterocyclic products are in the range of 80-100%, considerably higher than those reported in literatures.
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■ Recent Progress of Phthalimidine Syntheses
Ichiro Takahashi* and Minoru Hatanaka
*Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Fukui University, Bunkyo, Fukui-Shi 910-8507, Japan
Abstract
Phthalimidine (2,3-dihydro-1H-isoindol-1-one) syntheses in recent years are reviewed primarily for those involving synthetic auxiliary-mediated mild Mannich type condensation reactions.