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. 32, No. 11, 1991
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■ Regioslective Synthesis of 2-Substituted 3-Nitropyridines by One-Pot Reaction of Either 4- or 6-Substituted 1-Methyl-3,5-dinitro-2-pyridones with Ketones and Ammonia
Yasuo Tohda,* Tooru Kawara, Miyuki Eiraku, Keita Tani, Masahiro Ariga, and Yutaka Mori
*Department of Chemistrty, Osaka Kyoiku University, Minamikawahori-cho 4-88, Tennoji-ku, Osaka 582-8582, Japan
Abstract
Regioselective synthesis of 2-substituted 3-nitropyridines was achieved by one-pot reaction of either 4- or 6-substituted 1-methyl-3,5-dinitro-2-pyridones with ketones in the presence of ammonia. The selectivity is interpreted in terms of steric factor of substituent on the pyridone.
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■ An Electron Transfer Reaction in the Imidazo[2,1-b]thiazole Series
Patrice Vanelle,* Nacer Madadi, José Maldonado, Luc Giraud, Jean-François Sabuco, and Michel P. Crozet*
*Laboratorie de Chimie Organique, Faculté de Pharmacie, Université d’Aix-Marseille II, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France
Abstract
The C-alkylation reaction of 5-nitro-6-chloromethylimidazo[2,1-b]thiazole by the 2-nitropropane anion is shown to proceed by the SRN1 mechanism. This mechanism is confirmed by the inhibitory effects of dioxygen, p-dinitrobenzene, cupric chloride and TEMPO.
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■ A New Synthetic Route to Benzazocines Including the First Example of 2-Benzazocines
Jyoji Kurita, Takeshi Yamanaka, and Takashi Tsuchiya*
*Faculty of Pharmaceutical Sciences, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan
Abstract
1-Ethoxy-2-benzazocine (6), the first example of 2-benzazocines, was prepared from 1-isoquinolone (1) via 2a,8b-dihydrocyclobut[c]isoquinolone (4). Similarly, 2-alkoxy-1-benzazocines (12a,b) were obtained from 2-quinolone (10) via the cyclobuta[c]quinolone (11).
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■ Synthesis and DNA Binding Properties of a Purine Analogue of Bisbenzimide
Moses Lee,* P. Hunter Spotts, Jeffrey Eckert, Clint Walker, and Jennifer A. Nobles
*Department of Chemistry, Furman University, Greenville, South Carolina, U.S.A.
Abstract
The synthesis of a purine containing analogue (1) of bisbenzimide (2) and its DNA binding properties are described. Analogue 1 is found to have increased tolerance for binding to GC sites implying the formation of the new hydrogen bonds between guanine-2-NH2 in the minor groove of DNA and the concave purine N3 atom of 1.
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■ Intramolecular Rearrangement of 2-(2-Propynylsulfinyl)tropone and Its Homologues to Cyclohepta[b]thiophen-8-ones
Bing Zhu Yin, Akira Mori,* and Hitoshi Takeshita*
*Instituete of Advanced Material Study, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan
Abstract
Thermal reaction of 2-(2-alkynylsulfinyl)tropones afforded 3-acylcyclohepta[b]thiophen-8-ones, their dihydro derivatives as well as deacylated 2,3-dihydrocyclohepta[b]thiophen-8-ones. Deuterium labelling experiment confirmed the intramolecular reaction mode, which is different from the mechanism reported for the reaction of 2-(2-propenylsulfinyl)tropones.
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■ Use of 2D Nmr for the Assignment of Structure of 1,3,2-oxazaphospholidin-2-ones
Camille A. Boulet,* Scott J. Tregear, and Arnold S. Hansen
*Defence Research Establishement Suffield, P.O. Box 4000, Medicine Hat, Alberta T1A 8K6, Canada
Abstract
Reaction of a chiral amino alcohol with an alkyl phosphorodichloridate gives a mixture of diastereomeric 1,3,2-oxazaphospholidin-2-ones which are epimeric at phosphrous. Analysis by 1D and 2D nmr has shown that it is possible to establish the absolute configuration at phosphorus by nmr techniques. Specifically, stereospecific differences in chemical shifts and NOESY spectra for each isomer are used to establish the absolute stereochemistry at phosphorus for (4R,5S)-2-ethoxy-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidin-2-one diasteremers.
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■ A Convenient Synthesis of Five-membered Heteroaryl-substituted Pyridines
Min-Jen Shiao,* Li-Hua Shih, Win-Long Chia, and Tay-Yuan Chau
*Institutue of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei,11529, Taiwan, R.O.C.
Abstract
Five-membered heteroarylpyridines (3) or (4) such as furylpyridines, thienylpyridines, imidazolylpyridines and pyrrolylpyridines were obtained regioselectively in appreciable yields (40-67%) by reaction of heteroaryllithium salts with N-ethoxycarbonylpyridinium chloride (1) followed by oxygen oxidation.
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■ Synthesis of Conformationnaly Restrained Analogs of 7-n-Butyryl-2,3-dihydro-3-oxo[1,4]benzoxazine, a Normolipemic Pharmacophoric Pattern
Ziaeddine Moussavi, Patrick Depreux, Isabelle Lesieur,* and Jacques Sauzières
*Laboratorie de Chimie Thérapeutique, Faculté de Pharmcie, Université de Lille 2, 3, rue du Professeur Laguesse, BP 83, 59045 Lille Cedex, France
Abstract
Original conformationnaly restrained analogs of 7-n-butyryl-2,3-dihydro-3-oxo[1,4]benzoxazine, a normolipemic pharmacophoric pattern were synthesized from benzoxazinyl or benzoxazolinyl precursors.
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■ A New Synthetic Approximation to Thiazoles with a Versatile Persubstitution and/or Perfunctionalization
Carlos Alvarez-Ibarra,* Rosario Asperilla, César de Dios-Corredor, Elena Martínez-Santos, and Mario Luz Quiroga
*Departamento de Química Orgánica, Facultad de Química, Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
A new synthetic approach to 2-alkyl-, 2-aryl-, and 2-N-alkylaminothiazoles has been carried out. This strategy is based on the high versatility of synthons derived from 2-methylthiothiazoles.
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■ Preparation of New Chiral Piperidine Epoxides
Anna Diez, Lluís Vilaseca, Isabel López, Mario Rubiralta,* Christian Marazano, David S. Grierson, and Henri-Philippe Husson
*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain
Abstract
The new chiral piperidine epoxides (11b), (12b), and (13b) were prepared by MCPBA oxidation of 1,2,3,6-tetrahydropyridine (5b). Compound (5b) was obtained by NaBH4 reduction of pyridinium salt (4b) derived from the Zincke-König reaction of 2b and (R)-(-)-phenylglycinol.
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■ Synthesis and Tautomerism of 2,4-Dihydroxyquinolines
José Luis García Ruano,* Concepción Pedregal, and Jesús H. Rodrìguez*
*Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain
Abstract
The reaction of ethyl N-[2-(2-Z-acetyl)phenylcarbamates with NaH/THF yields 3-Z-2,4-dihydroxyquinolines [Z=SMe, SOMe, SO2Me and CN]. The study of the tautomeric equilibria of all these substrates by 13C-nmr shows that thioether and nitrile exhibit the 2-quinolone structure, whereas the sulfoxide and probably the sulfone exist as 4-quinolone tautomers.
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■ Stereochemical Characteristics of SET-promoted Photochemical Reactions of Dihydroisoquinolinium Salts
In-Seop Cho, Shirley S. S. Chang, Chihmei Ho, Chao-Pin Lee, Herman L. Ammon, and Patrick S. Mariano*
*Department of Chemsitry and Biochemistry, University of Maryland, College Park, MD 20742, U.S.A.
Abstract
Single electron transfer (SET) promoted photocyclization reactions of a series of silylbenzyl- and silylalkenyl-dihydroisoquinolinium perchlorates have been explored in order to evaluate the extent and source of stereochemical control in these N-heterocycle forming, diradical cyclization processes.
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■ The [2,3] Sigmatropic Rearrangement of Sulfilimines from 3-Exomethylenecephams
Nancy J. Snyder,* Jonathan W. Paschal,* Thomas K. Elzey, and Douglas O. Spry
*Lilly Reserach Laboratories, Lilly Corporate Center, Eli Lilly & Company, Indianapolis, IN 46285-4813, U.S.A.
Abstract
3-Exomethylenecepham sulfides react with phthalimidonitrene and the resulting sulfinimine undergoes a [2,3] sigmatropic rearrangement to give the 1,2,6-thiadiazepine azetidinone ring system.
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■ Tin (IV) Chloride-promoted Reactions of α-Hydroxy Nitriles with β-Dicarbonyl Compounds Synthesis of 4-Amino-2,5-dihydro-2-furanones and Their Conversion into Tetronic Acid Derivatives
Augusto C. Veronese,* Rosella Callegari, and Antonella Bertazzo
*Dipartimento di Scienze Farmaceutiche, Università degli Studi di Ferrara, Via Scandiana 21 di Mortara 17-19, I-44100 Ferrara, Italy
Abstract
β-Keto esters and β-diesters react with α-hydroxy nitriles in the presence of stoichiometric amounts of tin(IV) chloride to give 3-acyl-4-amino-2(5H)-furanones (2) and ethyl 4-amino-2,5-dihydro-2-oxofuran-3-carboxylates (3). The acyldihydrofuranones (2) can be converted into acyltetronic acid derivatives (6) while the ethyl furan-3-carboxylates (3) can be converted into tetronic acids (8).
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■ A Novel 1,6-Cyclization of Imidazolium N-Allylides (2): Formation of the Mesomeric Betaine, 7-Iminoimidazo[1,2-a]pyridiniumide
Yoshiro Matsuda,* Hiromi Gotou, Keisuke Katou, Hiroshi Matsumoto, Makoto Yamashita, Kimitoshi Takahashi, Shizuki Ide, Kazuki Furuno, and Katsura Torisu
*School of Pharmaceutical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan
Abstract
Treatment of imidazolium N-allylide (3) in refluxing 1,2,4-trimethylbenzene resulted in 1,6-cyclization to give the mesomeric betaine, 7-iminoimidazo[1,2-a]pyridiniumide (4). On the other hand, heating of 1-cyanoimidoylmethylimidazolium N-ylide (6) in refluxing 1,2,4-trimethylbenzene underwent 1,6-cyclization and debenzylation to give 8-aminoimidazo[1,2-a]pyrazine (7). Furthermore, treatment of the imidazolium salt (1a) and ethyl ethoxymethylenenitroacetate (2d) with K2CO3 in DMSO afforded the mesomeric betaine, imidazo[1,2-a]pyridiniumide (12), whereas the reaction of 1a and nitroketene dithioacetal (2e) with K2CO3 in DMSO resulted in 1,5-dipolar cyclization to produce pyrrolo[1,2-a]imidazole (13) and pyrrolo[1,2-a]pyrazine (14).
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■ Synthesis of D-Allosan from Levoglucosenone
Katsuya Matsumoto,* Takashi Ebata,* Koshi Koseki, Hiroshi Kawakami, and Hajime Matsushita
*Life Science Research Laboratory, Japan Tobacco Inc., 6-2, Umegaoka, Midori-ku, Yokohama, Kanagawa 227-8512, Japan
Abstract
The stereoselective reduction and cis-dihydroxylation of levoglucosenone (1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose), gave D-allosan (1,6-anhydro-β-D-allopyranose) in high yield.
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■ Chemistry of Viologens
Wanda Sliwa,* Barbara Bachowska, and Natalia Zelichowicz
*Institute of Chemistry, Pedagogical University, Al. Armii Krajowej 13/15, 42-201 Czestochowa, Poland
Abstract
Pointing out electron acceptor properties of viologens, the outline of porphyrin-viologen systems, complexes of viologens with donors and polymeric viologens are described along with biological interset of viologens.