Regular Issue

Vol. 41, No. 1, 1995

22 data found. 1 - 22 listed
Communication | Regular issue | Vol 41, No. 1, 1995, pp.1-4
Published online:
DOI: 10.3987/COM-94-6898
Stereoselective Preparation of 6-β-Bromopenicillanic Acid Derivatives

Irena Lukic*

*PLIVA Research Institute, Prilaz Baruna Filipovica 89, 41000 Zagreb, Croatia

Abstract

A new stereoselective method for the preparation of 6-β-bromopenicillanates is described. It comprises the reaction of 6,6-dibromopenicillanates with silver nitrate in 2-propanol.

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Communication | Regular issue | Vol 41, No. 1, 1995, pp.5-8
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DOI: 10.3987/COM-94-6917
Simple Syntheses of Marine Alkaloid, (±)-Chelonin A, and Its Analogs

Masanori Somei*, Kazuko Aoki, Yoshiyuki Nagahama, and Kyoko Nakagawa

*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920, Japan

Abstract

The first total synthesis of (±)-chelonin A and syntheses of its analogs are achieved based on 1-hydroxyindole chemistry.

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Communication | Regular issue | Vol 41, No. 1, 1995, pp.9-12
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DOI: 10.3987/COM-94-6925
Synthetic Approach toward the Minimal Active Structure of Phomopsin-ustiloxin Class of Antibiotics: Construction of 13-Membered Cyclic Peptide Skeleton

Ryoh Mutoh, Ryuichi Shirai, Yukiko Koiso, and Shigeo Iwasaki

*Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113, Japan

Abstract

The 13-membered cyclic peptides (5a and 5b), the core structure of phomopsin-ustiloxin class of antibiotics, have been synthesized. The final macrolactamization was overcome by the intramolecular aminolysis of corresponding ω-amino pentafluorophenyl ester.

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Communication | Regular issue | Vol 41, No. 1, 1995, pp.13-16
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DOI: 10.3987/COM-94-6927
A Facile Preparation of β-Alky-β-phenylthio-α,β-unsaturated Carbonyl Compounds in a Synthesis of Alkyl Substituted Thiophene-2-carboxylic Esters

Hsi-Hwa Tso* and Yu-Jiun Chen

*Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, R.O.C.

Abstract

A facile two-step or three-step one-flask procedure for a synthesis of β-alkyl-β-phenylthio-α,β-unsaturated carbonyl compounds (3a-j) from readily prepared 3-methoxy-1-phenylthio-1-propyne (1) is described. Condensation of 3a-j with methyl thioglycolate readily affords a number of 3-alkyl- and 3,5-dialkylthiophene-2-carboxylic methyl esters.

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Communication | Regular issue | Vol 41, No. 1, 1995, pp.17-20
Published online:
DOI: 10.3987/COM-94-6933
Reduction of Aromatic Ketones into Methylenes Using Triethylsilane and Titanium Tetrachloride. Synthesis of 2-Aminobutanoic Acids

Michihisa Yato, Koichi Homma, and Akihiko Ishida*

*Organic Chemistry Research Laboratory, Tanabe Seiyaku Co., Ltd., 2-2-50, Kawagishi, Toda, Saitama 335, Japan

Abstract

Several N-protected 2-aminobutanoic acids (3) with aromatic or heteroaromatic ring at their terminal position were prepared in good yields by reduction of the corresponding ketones (1) with triethylsilane (Et3SiH) in the presence of titanium tetrachloride (TiCl4). The reduction proceeded without racemization and was successfully applied to the synthesis of optically active 2-aminobutanoic acids (6).

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.21-28
Published online:
DOI: 10.3987/COM-94-6764
Reactivity of Aminoethylimidazo[1,2-a]pyridine : Access to Aza-γ-carboline Series

Anne Jouanisson, Olivier Chavignon, Jacques Couquelet, Jean-Claude Teulade*, Jean-Louis Chabard, and Gérard Dauphin

*Départment d'Analyse Structurale et de Pharmacologie, Faculté de Pharmacie, UMR INSERM 484, B P 38, 28 P. H. Dunant, 63001 Clermont-Ferrand CEDEX 1, France

Abstract

From 2-(2-aminoethyl)imidazo[1,2-a]pyridine (1), the synthesis of compounds possessing the azatetrahydrocarboline moiety was described. The Fujii procedure did not afford the expected tetracyclic compound (5). However, the Pictet-Spengler reaction led to tricyclic aza-γ-carbolinic type compounds (8a-c).

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.29-36
Published online:
DOI: 10.3987/COM-94-6846
Synthesis of Compounds with the Novel 2,3,7-Triazaphenalene Ring System

Tshilundu Mulamba, Rachida El Boukili-Garré, Denis Séraphin, Eric Noé, Catherine Charlet-Fagnère, Jacques Hénin, Jacqueline Laronze, Janos Sapi, Roland Barret, Jean-Yves Laronze*, and Jean Lévy

*Laboratoire de Chimie Thérapeutique, Laboratoire de Transformations et Synthèse de Substances Naturelles URA 492 CNRS, Université de Reims Champagne-Ardenne, Faculté de Pharmacie, 51 rue Cognacq-Jay, F-51096 Reims, France

Abstract

The title compounds (1a) and (1c-f) were prepared from the new 5-oxo-5,6,7,8-tetrahydroquinolines (2a) and (2c,d), which were synthesized from cyclohexane-1,3-dione.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.37-46
Published online:
DOI: 10.3987/COM-94-6857
Substituted 3-Aminothieno[2,3-b]pyridine-2-carboxamide as a Synthon for Polyheterocyclic Compounds. Preparation of New Pyridothieno-1,2,3-triazines and Related Derivatives

Carlos Peinador, Ma. Carmen Veiga, Vicente Ojea, and José Ma. Quintela

*Departamento de Química Fundamental e Industrial, Facultad de Ciencias, Universidad de La Coruña, Campus de A Zapateira, E-15071, La Coruña, Spain

Abstract

Pyrido[3’,2’:4,5]thieno[3,2-d]-1,2,3-triazines (2) and (3) were synthesized from 3-aminothieno[2,3-b]pyridine (1) by diazotization and subsequent treatment with electrophilic reagents. Reaction of triazinone (2) with phosphorus oxychloride lead to a mixture of the triheterocyclic compound (4) and the 4-chlorosubstituted triazine (5). Aminolysis of 4 with either hydrazine or primary and secondary amines yielded the derivatives (7a-h). Nitrosation of 7a afforded the 4-substituted triazinone (8). Finally, substituted 1,3,4-oxadiazole (9) was prepared from acylhydrazine (7a) and triethyl orthoformate.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.47-56
Published online:
DOI: 10.3987/COM-94-6871
Synthesis of New 1-Chalcogenapurines by the Reaction of 5-Aminoimidazole-4-carbonitrile with Isochalcogenocyanates

Hiroatsu Matsumoto*, Sumiko Hara, Nobuyuki Nagata, Kazuyoshi Ikeda, and Yoshihisa Mizuno

*Reseach Laboratory, Minophagen Pharmaceutical Co., 2-5233, Komatubara, Zama 228, Japan

Abstract

1-Chalcogenapurines[1-thiapurine derivatives (6,12c,d) and 1-selenapurine derivative (15)] and 1-substituted 1,6-dihydro-6-imino-9H-purine-2(3H)-chalcogenone (4a,b,13) were synthesized by the reaction of 5(4)-aminoimidazole-4(5)-carbonitrile (3) with various isochalogenocyanates in pyridine. The reaction of 3 with methyl isothiocyanate in pyridine afforded only the 1,6-dihydro-1-methyl-6-imino-9H-purine-2(3H)-thione (4a). On the other hand, the reactions of 3 with ethoxycarbonyl isothiocyanate, benzoyl isothiocyanate or benzhydryl isoselenocyanate preferentially gave the 1-chalcogenapurine derivatives (12c,d,15). In turn, both 1,6-dihydro-1-phenyl-6-imino-9H-purine-2(3H)-thione (4b) and 6,9-dihydro-2-phenylamino-6-(3-phenylthioureido)imino-1-thiapurine (6) were produced by the reaction of 3 with phenyl isothiocyanate. Modes of cyclization reactions involving 3 and isochalcogenocyanate (R-N=C=X, X; S,Se) depend in remarkable extent on the chalcogene atom as well as R portion of R-N=C=X.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.57-70
Published online:
DOI: 10.3987/COM-94-6875
Studies on the Alkylation of Chiral, Non-racemic, Tricyclic Pyrrolidinones

John A. Ragan* and Michelle C. Claffey

*Pfizer Central Research, Eastern Point Road, Groton, CT 06340, U.S.A.

Abstract

Condensation of cyclic keto acids with chiral amino alcohols provides tricyclic pyrrolidinones with high levels of diastereoselectivity. These pyrrolidinones can be alkylated via their lithium or sodium enolates. Optimal alkylation conditions vary with the nature of the amino alcohol; the phenylglycinol-derived pyrrolidinones suffer from an apparent benzylic metallation, whereas the valinol and norephedrine-derived substrates are good alkylation substrates. Application of this methodology to a vinylsilane/iminium ion cyclization approach to the synthesis of Whitesell’s amine was also investigated.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.71-86
Published online:
DOI: 10.3987/COM-94-6877
Regioselective Synthesis of Pyrimidines from Ketene Dithioacetals or Alkoxymethylene Compounds

Antonio Lorente*, Laura Vaquerizo, Avelino Martín, and Pilar Gómez-Sal

*Department of Organic Chemistry, University of Alcalá, 28871 Alcalá de Henares (Madrid), Spain

Abstract

Regioselective cyclizations of the condensation products obtained by the reaction of nitrogen nucleophiles with ketene dithioacetals or alkoxymethylene compounds are reported. Stereoelectronic factors or geometry of the carbon-carbon double bond determine the regioselectivity of heterocyclization processes.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.87-94
Published online:
DOI: 10.3987/COM-94-6887
1',2',6'-Thiadiazine 1',1'-Dioxide and Imidazo [4',5'-c][1',2',6']thiadiazine 2',2'-Dioxode 1,3-Oxathiolane Nucleoside Analogues: Synthesis and Anti-HIV-1 Activity

Tibor Breining, Alex R. Cimpoia, Tarek S. Mansour*, Nick Cammack, Philippa Hopewell, and Claire Ashman

*BioChem Therapeutic Inc., 275 Armand-Frappier Boulevard Laval, Québec, Canada H7V 4A7

Abstract

A series of 1,3-oxathiolanes containing the 1,2,6-thiadiazine dioxide moieties were synthesized by various coupling conditions of the oxathiolane sugar (3) and silylated 1,2,6-thiadiazine dioxides (4-7) as bases. The compounds were evaluated for their potential anti-HIV activities in MT-4 cells and were found to lack activity at 100 μg/ml.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.95-102
Published online:
DOI: 10.3987/COM-94-6888
Acid Decomposition of the Antimalarial Beta-Arteether

Nancy Acton* and Ronald J. Roth

*Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, DC 20307-5100, U.S.A.

Abstract

The antimalarial agent β-arteether was reacted with aqueous ethanolic HCl. Four compounds (11,12,13,and 14) were isolated. Two, 11 and 12, have the same structure as analogs recently reported by Baker and Chi. Compound (13) is spectroscopically nearly identical with another compound isolated by Baker and Chi, but facile electrochemical reduction of this material suggests that the compound is in fact a peroxide.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.103-110
Published online:
DOI: 10.3987/COM-94-6889
An Efficient Synthesis of 1-(o-Vinylenebenzyl)benzimidazolin-2-ones

Sung Cheol Yoon and Kyongtae Kim*

*Department of Chemistry, Seoul National University, Seoul 151-742, Korea

Abstract

5H,13H-benzo[5,6][1,3]thiazepino[4,3-a]benzimidazole (2), prepared by the reaction of benzimidazoline-2-thione with α,α’-dibromo-o-xylene in the presence of sodium hydride in tetrahydrofuran, was oxidized by m-chloroperbenzoic acid to give the corresponding sulfone which was treated with n-butyllithium at -78°C, followed by addition of aldehydes to give the title compounds in excellent yields.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.111-117
Published online:
DOI: 10.3987/COM-94-6899
A New Entry to the 1,7,10-Anthyridine System

Juan Vilar, Carlos Peinador, Ma. Carmen Veiga, Vicente Ojea, and José Ma. Quintela*

*Departamento de Química Fundamental e Industrial, Facultad de Ciencias, Universidad de La Coruña, Campus de A Zapateira, E-15071, La Coruña, Spain

Abstract

A synthesis for the 1,7,10-anthyridine system by condensation of ethyl 3-cyano-2-ethoxy-7-methyl-4-phenyl-1,8-naphthyridine-6-carboxylate (1) and DMFDMA, followed by ring closure with ammonium acetate is reported. The proposed procedure allows the easy preparation of 7-substituted 1,7,10-anthyridin-6-(7H)-ones (5) and 6-substituted 1,7,10-anthyridines (6) and (7).

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.119-130
Published online:
DOI: 10.3987/COM-94-6915
Indoles XIII. Syntheses and Stereochemistry of 14H-Bisindolo[2,3-a][3,2-h]quinolizine and of Some Benz[a]indolo[3,2-h]quinolizines

Jochen Lehmann*, Martin Nieger, and Thomas Witt

*Pharmazeutisches Institut der Universität Bonn, An der Immenburg 4, D-53121 Bonn, Germany

Abstract

Starting from hexahydrobanz[a]indolo[3,2-h]quinolizines (1a-c) and hexahydrobisindolo[2,3-a][3,2-h]quinolizine (4)2 we succeeded in generating their completely dehydrogenated derivatives. The structures were investigated by 1H- and 13C-nmr spectroscopy as well as by X-ray analysis.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.131-146
Published online:
DOI: 10.3987/COM-94-6918
Lithiation of N-Substituted Benzotriazoles

Alan R. Katritzky*, Alexey V. Ignatchenko, and Hengyuan Lang

*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, U.S.A.

Abstract

The behavior on lithiation of seventeen N-substituted benzotriazoles was investigated. In seven cases, the N-substituent was either removed or no lithiation occured, in six instances lithiation occurred in the N-substituent and in the four remaining compounds lithiation occurred at the ring 7-position, albeit in low yield.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.147-159
Published online:
DOI: 10.3987/COM-94-6920
An Efficient Synthesis of (2S,4S)-2-Substituted 4-Mercaptopyrrolidine Derivatives

Haruki Matsumura, Takashi Bando, and Makoto Sunagawa*

*Development Research Laboratories I, Sumitomo Pharmaceuticals Research Center, 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554, Japan

Abstract

An efficient synthesis of (2S,4S)-2-substituted 4-mercapto-1-p-nitrobenzyloxycarbonylpyrrolidine (2) was studied. Intramolecular cyclization of (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxy-2-pyrrolidinethiocarboxylic acid (8), derived from trans-4-hydroxy-L-proline (3), afforded (1S,4S)-5-p-nitrobenzyloxycarbonyl-2-thia-5-azabicyclo[2.2.1]heptan-3-one (7). Reaction of 7 with primary amine, secondary amine and alkoxide afforded corresponding 2 in high yield.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.161-174
Published online:
DOI: 10.3987/COM-94-6924
New Synthetic Route to Imidazo[4,5-c]pyridines by the Thermal Electrocyclic Reaction of 1-Azahexatriene Systems

Haruyuki Yashioka, Tominari Choshi, Eiichi Sugino, and Satoshi Hibino*

*Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Fukuyama, Hiroshima 729-02, Japan

Abstract

New routes to 1H- and 3H-imidazo[4,5-c]pyridines have been developed by the thermal electrocyclic reaction of 1-azahexatriene systems involving the imidazole 4,5-bond.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.175-186
Published online:
DOI: 10.3987/COM-94-6928
A Thermal Wolff Rearrangement-benzannulation Route to Naphth[2,1-d]isoxazoles, [1]Bezofuro[6,7-d]- or [5,4-d]isoxazoles and 1,2-Benzisoxazoles

Ya Ping Chen, Bernard Chantegrel, and Christian Deshayes*

*Institut National des Sciences Appliquées, Laboratoire de Chimie Organique, Département de Biochimie, Batiment 403, 20 Avenue Albert Einstein, 69621 Villeurbanne Cedex, France

Abstract

The title compounds substituted in position 4 by a dimethylphosphono group and in position 5 by a hydroxy group were prepared by the thermal decomposition of dimethyl 2-(5-aryl-(or furyl or alkenyl)-3-methylisoxazol-4-yl)-2-oxo-1-diazoethylphosphonates through a tandem Wolff rearrangement-benzannulation sequence.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.187-190
Published online:
DOI: 10.3987/COM-94-6932
Two New Acridone Alkaloids from a Citrus Plant

Yuko Takemura, Yoko Matsushita, Satomi Onishi, Tomomi Atarashi, Junichi Kunitomo, Motoharu Ju-ichi,* Mitsuo Omura, Chihiro Ito, and Hiroshi Furukawa

*Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Hyogo 663, Japan

Abstract

Two new acridone alkaloids, named furoparadine (1) and trans-dihydroxycitracridone-I (2), were isolated from the root of Marsh grapefruit (Rutaceae) and their structures were elucidated on the basis of stectroscopic methods.

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Paper | Regular issue | Vol 41, No. 1, 1995, pp.191-198
Published online:
DOI: 10.3987/COM-94-6938
Paratocarpins A - E, Five New Isoprenoid-substituted Chalcones from Paratocarpus venenosa Zoll.

Yoshio Hano, Naoyuki Itoh, Akio Hanaoka, Yoshimitsu Itoh, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274, Japan

Abstract

Five new isoprenoid-substituted chalcones, paratocarpins A(1) , B(2), C(3), D(4), and E(5) were isolated from the Indonesian moraceous plant, Paratocarpus (= Artocarpus) venenosa Zoll. The structures of paratocarpins A, B, C, D, and E were shown to be 1,2,3,4, and 5, respectively, on the basis of spectroscopic data.

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22 data found. 1 - 22 listed