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. 34, No. 10, 1992
Published online:
■ The Chemistry of 1-Hydroxyindole Derivatives: Nucleophilic Substitution Reactions on Indole Nucleus
Masanori Somei,* Toshiya Kawasaki, Yoshikazu Fukui, Fumio Yamada, Tetsuya Kobayashi, Harumi Aoyama, and Daisuke Shinmyo
*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920, Japan
Abstract
Nucleophilic substitution reactions were newly found to occur generally in the chemistry of 1-hydroxyindole derivatives. Its application to the synthesis of a phytoalexin, brassicanal A, is reported.
Published online:
■ Synthesis and Stereochemistry of Tropane 6-Spiro-hydantoins
Mercedes Villacampa,* Manuel Martínez, Gregorio González-Trigo, and Mónica M. Söllhuber
*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain
Abstract
The synthesis of several representatives of the previously unknown N-alkyl-nortropane-6-spirohydantoin ring system by Bucherer-Bergs reaction of 8-alkyl-8-azabicyclo[3.2.1]octan-6-ones is described. 3-Oxo derivatives of the parent structure were also prepared. The stereochemical outcome of the Bucherer-Bergs reaction is discussed on the basis of 1H-nmr and 13C-nmr data.
Published online:
■ The Serendipitous Formation of an Unusual Methyl N’-Cyano-N-[5-methylthio-1,2,4-triazol-3-ylidene]carbamimidothioate and Subsequent Reactions
Dennis J. Hlasta,* Malcolm R. Bell, Rudolf K. Kullnig, and Joseph R. Wetzel
*Departments of Medical Chemistry and Molecular Characterization, Sterling Winthrop Pharmaceuticals Research Division, 81 Columbia Turnpike, Rensselaer, New York 12144, U.S.A.
Abstract
Dimethyl cyanocarbamimidodithioate (1) (2 equivalents) reacts with 1,2-dimethylhydrazine to afford the cyclic derivative, methyl N’-cyano-N-(5-methylthio-1,2,4-triazol-3-ylidene)carbamimidothioate (5), instead of an expected acyclic derivative. The triazole (5) undergoes di-addition-elimination reactons with primary aliphatic amines to afford N’’-cyano-N-(5-amino-1,2,4-triazol-3-ylidene)guanidines (6).
Published online:
■ A Synthesis of 1,2,3,4-Tetrahydro-1,6-naphthyridines
Pedro J. Victory,* Jordi Teixidó, and José I. Borrell
*CETS Institut Químic de Sarrià, (Universitat Ramon Llull), Departament de Química Orgànica, E-08017 Barcelona, Spain
Abstract
8-Cyano-3,4-dihydro-1,6-naphthyridin-2(1H)-ones were obtained by nucleophilic substitution of the methoxyl group of 5-cyano-3,4-dihydro-6-methoxy-2(1H)-pyridones (5a-d) by malononitrile or cyanoacetamide followed by cyclization in acidic or basic medium.
Published online:
■ Direct Amination. Part 4. Reactions of Indoles with Primary Aromatic Amines and Iodosobenzene Diacetate
Liberato Cardellini, Lucedio Greci,* Eziana Maurelli, Mario Orena, Pierluigi Stipa, and Giorgio Tosi
*Dipartimento di Scienze dei Materiali e della Terra, Università, Via Brecce Bianche, I-60131 Ancona, Italy
Abstract
Indole, 2-methylindole, 2-phenylindole, and primary aromatic amines react with iodosobenzene diacetate leading both to 2-arylamino-3-arylimino-3H-indole in the case of indole and 2-methylindole, and to 2-phenyl-3-arylimino-3H-indole in the case of 2-phenylindole. The reaction is believed to proceed through the formation of a nitrenium ion formed by the interaction of iodosobenzene diacetate and primary aromatic amines and the mechanism is supported by experimental evidences. The methyl elimination from 2-methylindole is explained on the basis of the isolation of the possible intermediate and the formation of an aminal, whose decomposition leads to the reaction products. The intermediate aminal is proposed on the basis of the bis-(2-methylindol-3-yl)methane formation.
Published online:
■ A Facile and Convenient Synthetic Method for Fluorine-containing Pyridines, 1,2-Dihydropyridines, and 2-Pyridones
Etsuji Okada, Ryoichi Masuda, and Masaru Hojo*
*Department of Industrial Chemistry, Faculty of Engineering, Kobe University, Kobe 657, Japan
Abstract
1-Ethylthio- and 1-dimethylamino-4,4-bis(trifluoroacetyl)-1,3-butadienes (1, 2) reacted easily with aqueous ammonia and various primary amines under mild conditions to afford selectively the corresponding fluorine-containing pyridines (3), 1,2-dihydropyridines (4), and 2-pyridones (5) in excellent yields.
Published online:
■ Synthesis of 1,6:3,4-Dianhydro-β-D-talopyranose from Levoglucosenone: Epoxidation of Olefin via trans-Iodoacetoxylation
Katsuya Matsumoto,* Takashi Ebata,* Koshi Koseki, Koji Okano, Hiroshi Kawakami, and Hajime Matsushita
*Life Science Research Laboratory, Japan Tobacco Inc., 6-2, Umegaoka, Midori-ku, Yokohama, Kanagawa 227, Japan
Abstract
Levoglucosenone (1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose, 1) was converted to give 1,6:3,4-dianhydro-β-D-talopyranose (8) in good yield through stereoselective trans-iodoacetoxylation followed by basic hydrolysis.
Published online:
■ NOE Difference Spectroscopy Applied in Stereochemical Investigations of Two Diastereomeric Indoloquinolizidine Alcohols, Significant in the Preparation of Geissoschizine-Type Compounds
Reija Jokela
*Laboratory for Organic and Bioorganic Chemistry, Technical University of Helsinki, SF-02150 Espoo, Finland
Abstract
Complete 1H-nmr data were recorded for indoloquinolizidine alcohols (2a) and (2b), significant intermediates in the preparation of geissoschizine-type compounds, and for their benzoyl derivatives (3a) and (3b). The stereochemistry was deduced from NOE measurements.
Published online:
■ The Structures of Two Isomeric N-Formates from 3-O-Acetylsolasodine
Genjiro Kusano,* Chika Sekimoto, Mayumi Abe, Yasuko In, Hirofumi Ohishi, Toshimasa Ishida, and Norio Aimi
*Osaka University of Pharmaceutical Sciences, 2-10-65 Kawai, Matsubara, Osaka 580, Japan
Abstract
The structures of two isomeric N-formates, I (1) and II (2), prepared from O-acetylsolasodine, were determined by X-ray crystalographic analyses, and the isomerism between them was shown to be caused by the epimerization at C-22 during the formylation.
Published online:
■ Isolation of the Intermediates and Improved Synthesis of Pyrido[1’,2’:1,2]imidazo[4,5-b]pyrazines and -quinoxalines
Akira Katoh,* Shuhei Ueda, Junko Ohkanda, Mutsumi Hirota, Hiroshi Komine, and Keiryo Mitsuhashi
*Department of Industrial Chemistry, Faculty of Engineering, Seikei University, Musashino-shi, Tokyo 180, Japan
Abstract
2-(Pyrid-2’-yl)amino-3-chloro-5,6-dicyanopyrazines (IIa, IId, and IIe) and 2-(pyrid-2’-yl)amino-3-chloro-6-nitroquinoxalines (Va-c) were isolated for the first time in the course of the reaction of 2,3-dichloro-5,6-dicyanopyrazine (I) and 2,3-dichloro-6-nitroquinoxaline (IVa), respectively, with 2-aminopyridines. Furthermore, the yield of pyrido[1’,2’:1,2]imidazo[4,5-b]quinoxalines was remarkably improved due to the modification of the reaction conditions.
Published online:
■ Alkaloid N-Oxides
Angelo Albini
*Institute of Organic Chemistry, The University, V. P. Giuria 7, 10125 Torino, Italy
Abstract
More than 200 aliphatic and aromatic N-oxides have been individuated among natural-occurring alkaloids. The structures of these compounds as well as the role that N-oxides have in the synthesis and the chemical modification of alkaloids are reviewed.
Published online:
■ Synthesis of Mixed Thiophene-Pyrrole Heterocycles
Renée E. Niziurski-Mann and Michael P. Cava*
*Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, AL 35487-0336, U. S. A.
Abstract
The synthesis of mixed thiophene-pyrrole heterocycles has been reviewed. The systems under consideration are various isomeric thienylpyrroles as well as tricyclic analogs containing non-condensed combinations of two or three pyrrole and thiophene units.