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. 38, No. 12, 1994
Published online:
■ One-Pot Synthesis of Propellane Hetero Analogue from N-Phenyl-substituted 3-Acyl-1,2-dihydrocinnoline-1,2-dicarboximides under Phase-Transfer-catalyzed conditions
Satoko Tanaka, Kazuyoshi Seguchi,* and Akira Sera
*Faculty of Human Life and Environmental Sciences, Mukogawa-Women‘s University, Nishinomiya 663, Japan
Abstract
Novel propellane hetero analogues were prepared in one-pot from N-phenyl-substituted 3-acyl-1,2-dihydrocinnoline-1,2-dicarboximides under phase-transfer catalyzed.
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■ Synthesis of Annulated Furans with Various 3-Substituents via a Sequential Furannulation/ene Route
Akio Ojida, Akira Abe, and Ken Kanematsu*
*Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Abstract
Annulated furans with various 3-substituents were synthesized through the one-step synthesis of 3 and its ene reactions with enophiles.
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■ Synthesis of a New type of Antioxidant possessing Inhibitory Activity against HMG-CoA Reductase
Masakatsu Matsumoto,* Nobuko Watanabe, Eiko Mori, Misao Aoyama, Jun Kusunoki, and Tetsuaki Yamaura
*Department of Chemistry, Faculty of science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
Abstract
The 6-hydroxychromans (4) and (6), and 5-hydroxy-2,3-dihydrobenzo[b]furans (5) and (7) bearing a 4-hydroxypyran-2-one moiety were synthesized. All the compounds exhibited potent activity against lipid peroxidation. The chroman (4) possessed inhibitory activity against HMG-CoA reductase in addition to the antioxidant character.
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■ Synthesis of 2,3,5,6-Tetrahydroimidazo[2,1-b]thiazoles
Girts Kaugars,* Scott E. Martin, Stephen J. Nelson, and William Watt
*Animal Health Discovery Research, Upjohn Laboratory, The Upjohn Company, Kalamazoo, MI 49001a, U.S.A.
Abstract
The reactions of 2-amino-2-thiazoline with alkylating and acylating agents give initial reaction of the endocyclic nitrogen. Acyl groups, however, readily rearrange to the exocyclic nitrogen to give the products usually observed in these reactions. These observations clear up a considerable amount of confusion in the literature and lead to the efficient synthesis of 2,3,5,6-tetrahydroimidazo[2,1-b]thiazoles.
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■ Intramolecular Cyclization Reaction of Amido-Ureido (or Thioureido)-Acetals
Yong Sup Lee, Choong Sup Kim, and Hokoon Park*
*Organic Chemistry Laboratory, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea
Abstract
Intramolecular cyclization reaction of the compound having amide, urea and acetal functional groups was investigated under various conditions. In acidic conditions, the cylclization reaction of N-methyl-N‘-(2,2-dimethoxyethyl)-N‘-(alkyl- or phenylcarbamoyl)glycine amide proceeded only to afford imidazolinone derivative via an acyliminium ion intermediate formed by intramolecular amidoalkylation reaction of amide and acetal functional groups. However, the corresponding compounds having thiourea functional group resulted in the formation of iminothiazolidine derivatives as major product and pyrazinone compounds as minor product. In nearly neutral or basic conditions, both of ureido- or thioureidoacetals afforded hydantoin or thiohydantoin derivatives, respectively, in excellent yield.
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■ Synthesis of 5-Methoxy-2(1H)-quinolinone
María Fernández, Elena de la Cuesta, and Carmen Avendaño*
*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain
Abstract
Methylation of 5-hydroxy-2(1H)-quinolinone (1) is studied. The previous protection of the amide group in 1 is proposed as the more convenient method to obtain 5-methoxy-2(1H)-quinolinone (1a).
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■ Oxidation of 2-Mercaptobenzoheterazoles by Dimethyldioxirane. A New Method for a Synthesis of C-2 Substituted Benzimidazole, Benzoxazole, and Benzothiazole Derivatives
Giuseppe Frachey, Claudia Crestini, Roberta Bernini, Raffaele Saladino,* and Enrico Mincione
*Dipartimento Agrochimico Agrobiologico, Università degli Studi di Viterbo "La Tuscia", Via San Camillo de Lellis, 01100 Viterbo, Italy
Abstract
New and efficient reactions in which 2-mercaptobenzoheterazoles are selectively converted by dimethyldioxirane, under mild experimental conditions, to several C-2 substituted benzoimidazole, benzoxazole, and benzothiazole derivatives are reported.
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■ A Facile Epoxidation of 5-Methylene-1,3-dioxane-4,6-diones with Hydrogen Peroxide without Catalyst
Takashi Tsuno,* Kunio Sugiyama, and Hideo Ago
*College of Industrial Technology, Nihon University, 1-2-1, Izumi-cho, Narashino, Chiba 275-8575, Japan
Abstract
5-Methylene-1,3-dioxane-4,6-diones readily reacted with hydrogen peroxide without any catalyst and any bases to afford the spiro- and poryspirocyclic compounds containing an oxirane ring as crystalline products. Furthermore, the epoxidation of chiral 5-arylidene-1,3-dioxane-4,6-diones with hydrogen peroxide produced the two diastereomers whose purification by silica gel chromatography ensures 100% optical purity.
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■ Chromenes and Chromanones. Part II. The Birch Reduction of Precocene I and Precocene II
Miroslaw Aniol and Czeslaw Wawrzenczyk*
*Institute of Fundamental Chemistry, Agricultural University , Norwida 25, 50-357 Wroclaw, Poland
Abstract
The reduction of precocene I (1a), precocene II (1c) and 6-methoxy-2,2-dimethyl-2H-chromene (1b) with sodium or lithium in liquid ammonia was examined. The phenolic compounds and the bicyclic one with partially reduced benzene ring were obtained as the major products from precocene I and 1b, respectively. The demethoxylation during the reduction of precocene II was observed.
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■ Synthesis and Structural Assignment of Diastereomerically Pure N-Substituted 4-Alkylpyrrolidin-2-ones, Intermediates for the Preparation of 3-Alkylpyrrolidines in Both Enantiomerically Pure Forms
Barbara Cardillo, Roberta Galeazzi, Giovanna Mobbili, Mario Orena,* and Monica Rossetti
*Dipartimento di Scienze dei Materiali e della Terra, Università di Ancona, Via Brecce Bianche, I-60131 Ancona, Italy
Abstract
By radical cyclisation of N-[(S)-1-phenylethyl]-N-allyliodoacetamides (6a-d), 4-substituted pyrrolidin-2-ones (7a-d) and (8a-d) were prepared as diastereomeric equimolar mixtures which were separated by column chromatography. The preferred conformation of 7a-d and 8a-d was determined by molecular mechanics methods and the configuration of the newly introduced stereogenic center was assigned by 1H nmr data and further confirmed by NOE experiments. Compounds (7a-d) and (8a-d) can be converted into 3-alklpyrrolidines in both enantiomerically pure forms following procedures reported in the literature.
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■ Synthesis of 6-Formyl Derivatives of 5,8-Dimethoxycarbostyryl
J. Ignacio Ubeda, Carmen Avendaño,* J. Carlos Menéndez, and Mercedes Villacampa
*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain
Abstract
An efficient method is described for the preparation of 5,8-dimethoxy-2-oxo-1H-quinoline-6-carbaldehyde. Alternative strategies aimed at the synthesis of 4-methyl analogues are also studied.
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■ Formation of Organic Semiconductors: Synthesis of Charge Transfer Complexes between TCNQ Radical Anion Salt and Tropylium Ions Fused with Heterocyclic System
Kazuaki Ito and Katsuhiro Saito*
*Faculty of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
Abstract
Tropylium ions fused with heterocyclic systems were synthesized to measure their reduction potentials of - 015 to - 0.37 V vs SCE. Radical anion of TCNQ and these tropylium ions formed charge transfer complexes, which have conductivities of σ = 10-4 - 10-7 Scm-1, suggesting that the belong to semiconductors.
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■ Synthesis of Phosphono- and Phosphino-substituted Six-membered Heterocycles
Harald G. Krug, Richard Neidlein,* Claus Krieger, and Walter Kramer
*Pharmazeutisch Chemishes Institut, Im Neuenheimer Feld 364, 6900 Heidelberg, Germany
Abstract
3,6-Dihalopyridazines react with the sodium salts of cyanomethylphosphonic acid dialkyl esters or phenylphosphinic acid ethyl ester to yield phosphono- and phosphino-substituted pyridazines. The constitution of one reaction product is proved by an X-ray crystal structure analysis.
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■ Sythesis and Stereochemical Studies of New 2-(2-Furyl)cyclanones
Olivier Duval,* Ahmed Rguigue, and Louis M. Gomés
*Laboratoire de Chimie Organique et Thérapeutique, U.F.R de Médecine et Pharmacie, Université d‘Angers, 16, bd. Daviers, 49100 Angers, France
Abstract
A study was conducted on factors influencing product distributions in the two-step formation of novel 2-(2-furyl)cycloanones using 1H nmr coupling constants values and nOe difference experiments. The 3-(2-furyl)norbornan-2-one and 2-(2-furyl)-5,6-dimethoxy-3-methylidan-1-one unclei were chosen to illustrate pertinent stereochemical criteria which may be exploited in selecting desired derivatives of these species with well defined stereochemistry. These novel adaptable synthons deserved wider recognation as new heterocyclic system promotors.
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■ Novel and Selective Syntheses of New Analogues of Precocene-2 and Precocene-3 Containing 5-Methyl- or 8-Methyl-substituents
Tibor Tímár,* Péter Sebök, Tibor Eszenyi, and Joseph Cs. Jaszberenyi
*Department of Research, Alkaloida Chemical Co. Ltd., H-4440 Tiszavasvári, POB 1, Hungary
Abstract
New analogues of precocene-2 and precocene-3 containing 5-methyl- or 8-methyl-substituents have been synthesised in good yields utilising regioselective O-alkylation of 6,7-dihydroxy-2,2,5-trimethyl-4-chromanone and 6,7-dihydroxy-2,2,8-trimethyl-4-chromanone as the key step.
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■ Convenient Synthesis of a Simple Coumarin from Salicylaldehyde and Wittig Reagent (III): Synthesis of Nitrocoumarins
Takashi Harayama,* Kazumitsu Nakatsuka, Hiromi Nishioka, Kyoko Murakami, Yukiko Ohmori, Yasuo Takeuchi, Hisashi Ishii, and Kazuhiro Kenmotsu
*Faculty of Pharmaceutical Science, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan
Abstract
Reaction of nitrosalicylaldehydes (1) with carbenthoxymethylenetriphenylphosphorane in Et2NPh, in Ph2O, and in the absence of solvent (neat) at 210-215 °C was investigated. Reaction of 3-nitrosalicylaldehyde (1d) in Et2NPh afforded the benzoxazole (6) and the aminocoumarin (3e) along with the expected coumarin (3d). It was clarified that the origin of carbon-unit introduced for the formation of the benzoxazole ring came from the alkyl group of solvent.
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■ Synthesis and Activity of New Abscisic Acid Analogues Possessing Hetero Five-membered Ring in their Molecules
Tadao Asami* and Shigeo Yoshida
*The Institute of Physical and Chemical Research, Wako-shi, Saitama 351-0198, Japan
Abstract
The conjugated dienyl side chain of plant hormone abscisic acid was substituted with five-membered hetero-rings having a carboxyl group on their 2-position. Some of the synthesized compounds showed a remarkable activity similar to ABA in inhibiting cress seed germination and α-amylase induction by gibberellin in half-cut barley seed assays.