Regular Issue

Vol. 36, No. 12, 1993

21 data found. 1 - 21 listed
Communication | Regular issue | Vol 36, No. 12, 1993, pp.2657-2662
Published online:
DOI: 10.3987/COM-93-6488
A New Method for Introducing Acetylene Groups at the α-Position of the Pyrroliding Ring

Tatsuo Nagasaka,* Shiro Nishida, Koichi Adachi, Toshio Kawahara, Shu Sugihara, and Fumiko Hamaguchi

*Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

A new method has been established for introducing acetylene groups at the α-position of pyrrolidine ring, in which 2-ethoxy-N-ethoxycarbonylpyrrolidine reacts with tin(IV) acetylides in the presence of tin(II) triflate.

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Communication | Regular issue | Vol 36, No. 12, 1993, pp.2663-2667
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DOI: 10.3987/COM-93-6506
Formation of Novel Isoxazoline Spiro Compounds by a Reaction of Aryl Substituted α-Nitroacrylates with Titanium Tetrachloride and Toluene

Seiko Hirotani* and Shonosuke Zen

*School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641, Japan

Abstract

New spiroisoxazoline derivatives were synthesized via novel cyclization of arylsubstituted α-nitroacrylates (naphthyl and phenanthryl analogues) with TiCl4 and toluene. The structural determination by single crystal X-ray analysis is reported.

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Communication | Regular issue | Vol 36, No. 12, 1993, pp.2669-2672
Published online:
DOI: 10.3987/COM-93-6513
Structure of the endo 1:1 Adduct by Asymmetric Cycloaddition Reactions of Optically Active (R)-Allene-1,3-dicarboxylate with Furan: Determination of Its Absolute Configuration by X-Ray Analysis

Izumi Ikeda, Akie Gondo, Motoo Shiro, and Ken Kanematsu*

*Institute of Synthetic Organic Chemistry, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

Abstract

Asymmetric Diels-Alder reactions of optically active (R)-allene-1,3-dicarboxylate with furan in the presence of Lewis acid proceeded to afford the endo-adduct selectively in moderate yield. The absolute configuration of the adduct was confirmed by X-ray analysis.

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Communication | Regular issue | Vol 36, No. 12, 1993, pp.2673-2676
Published online:
DOI: 10.3987/COM-93-6528
Preparation of New Thiocarbanion Species Bearing Thiazolinyl and Benzothiazolyl Groups and Reactions with Carbonyl Compounds

Shinya Kohra, Hiroshi Ueda, and Yoshinori Tominaga*

*Faculty of Pharmaceutical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

2-Ttrimethylsilylmethylthiothiazoline (1) reacted with aromatic aldehydes in the presence of cesium fluoride or tris(dimethylamino)sulfur(trimethylsilyl)difluoride (TASF) to give 2-heteroarylthioethanol (4) or thiiran (5) derivatives in good yields. The reactions of 2-trimethylsilylmethylthiobenzothiazole (2) with aromatic aldehydes are also discussed.

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Communication | Regular issue | Vol 36, No. 12, 1993, pp.2677-2680
Published online:
DOI: 10.3987/COM-93-6530
Synthesis of the First Examples of 1-Benzosilepine, 1-Benzogermepine, and 1-Benzarsepine Ring System

Jyoji Kurita, Shinichi Shiratori, Shuji Yasuike, and Takashi Tsuchiya*

*Faculty of Pharmaceutical Sciences, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan

Abstract

The first synthesis of 1,1-dimethyl-1-benzosilepine, 1,1-dimethyl-1-benzogermepine, and 1-phenyl-1-benzarsepines was achived by flash vacuum pyrolysis of the dihydrocyclobut[b]benzoheteroles (4, 7), prepared from the corresponding 1-benzoheteroles via three steps.

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Communication | Regular issue | Vol 36, No. 12, 1993, pp.2681-2686
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DOI: 10.3987/COM-93-6539
Synthesis of 3-(1’-Indanylidene)phthalides via Wittig-Horner Reaction of Dimethyl Phthalide-3-phosphonates and Their Conversion to the BCDE Ring Part of Fredericamycin A

Mitsuaki Watanabe,* Hitoshi Morimoto, and Sunao Furukawa

*Center for Instrumental Analysis, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

Wittig-Horner reaction of dimethyl phthalide-3-phosphonates with 1-indanones in the presence of bases was investigated. The 3-(1’-indanylidene)phthalides obtained above were transformed into dibenzo-1,4-diketospiro[4.4]nonanes, the BCDE ring system of fredericamycin A, by consecutive treatments with diisobutylaluminum hydride and pyridinium dichromate.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2687-2696
Published online:
DOI: 10.3987/COM-93-6459
A Facile, Convenient and Selective Homolytic Carbamolylation of Heteroaromatic Bases

Fausta Coppa, Francesca Fontana, Edoardo Lazzarini, and Francesco Minisci*

*Dipartimento di Chimica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy

Abstract

The oxidative decarboxylation of monoamides of oxalic acid provides carbamoyl radicals, which are useful for the selective arbamoylation of protonated heteroaromatic bases; this reaction represnets the first general and selective method for the N-alkyl or N-arylcarbamoylation of heteroaromatic bases. Compared to alkoxycarbonylation, this reaction is much more effective and selective, owing to more favourable polar and enthalpic effects. The importance of the steric effects is also emphasized.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2697-2705
Published online:
DOI: 10.3987/COM-93-6464
Synthesis of 1,7,10-Anthyridine Derivatives

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

*Departamento de Química Fundamental Industrial, Facultad de Ciencias, Universidad de La Coruña, Campus de A Zapateria, s/n, E-15071, La Coruña, Spain

Abstract

A convenient synthesis of 7-substituted 1,7,10-anthyridin-6(7H)-ones using an enamination ring closure sequence is described. This strategy makes a novel, potencially universal method for the preparation of this new tricyclic ring system.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2707-2721
Published online:
DOI: 10.3987/COM-93-6481
Synthesis of Potential Cytotoxic Quaternary Ammoniums by Oxidation of Eburnane Alkaloids

Guy Lewin,* Corinne Schaeffer, Alain Pierré, Nicolas Guilbaud, Ghanem Atassi, and Jacques Poisson

*Laboratoire de Pharmacognosie, Faculté de Pharmacie, 1, rue Vaubénard, 14032 Caen Cedex, France

Abstract

Oxidation of vincamine and substituted analogs on ring-A was carried out in two steps: benzylic oxidation by Jones reagent and aromatization of ring-C with Hg(OAc)2 or Tl(OCOCF3)3 in trifluoroacetic acid. Final compounds are quaternary ammoniums which exhibited weak cytotoxicity or no cytotoxicity according to substituents on ring-A and nature of ring-E.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2723-2732
Published online:
DOI: 10.3987/COM-93-6491
Synthesis of Various Substituted Dibenzo[b,d]pyranones Including Amino Acid Derivatives by SRN1 Methodology

Rene Beugelmans, Michèle Bois-Choussy,* Jacqueline Chastanet, Martine Le Gleuher, and Jieping Zhu

*Institut des Chimie des Substances Naturelles, C.N.R.S., Avenue de la Terrasse, Bat. 27, 91198 Gif-sur-Yvette Cedex, France

Abstract

An easy preparation of the title compounds involving a SRN1 ortho-arylation of phenolates by o-bromobenzonitrile followed by SiO2-catalysed lactonisation is described. Activated or not activated phenols are efficient. Access to benzonaphthopyranones is exemplified by the reactions with 2-naphtholate. Reactions with chiral p-hydroxyphenylamino acid derivatives are also reported.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2733-2743
Published online:
DOI: 10.3987/COM-93-6494
Condensed as-Triazine III: Synthesis of 2-Amino-6-azapurine (3-Aminoimidazo[4,5-e]-as-triazine) as a Potential Antitumor Agent

Dau-Chang Wei, Long-Chih Hwang, Chein-Hwa Han, Kuan-Han Lee, and Cherng-Chyi Tzeng*

*School of Chemistry, Kaohsiung Medical College, Kaohsiung City 807, Taiwan, R.O.C.

Abstract

2-Amino-6-azapurine, an aza analogue of guanine, has been prepared from its 3,5,6-triamino-as-triazine precursor and triethyl orthoformate under acidic conditions. 3-Amino-6-bromo-as-triazin-5-one was chosen as a proper starting material for the synthesis of this precursor. Thus, reaction of 3-amino-6-bromo-as-triazin-5-one with liquid ammonia and catalytic amount of fine copper powder gave 3,6-diamino-as-triazin-5-one which was then thiated with phosphorous pentasulfide in hexamethylhosphoric triamide to yield 3,6-diamino-as-triazin-5-thione. Methylation of 3,6-diamino-as-triazin-5-thione with methyl iodide under basic conditions gave 3,6-diamino-5-methylthio-as-triazine which was treated with methanolic ammonia to afford 3,5,6-triamino-as-triazine.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2745-2752
Published online:
DOI: 10.3987/COM-93-6495
1,2,4-Thiadiazino[3,4-b]benzothiazole: A New Cyclic Sulphenimine

Patrick Jimonet,* François Audiau, Michel Barreau, and Serge Mignani

*Rhone-Poulenc Rorer Central Rerearch, Centre de Recherches de Vitry-Alfortville, 13 Quai Jules Guesde, BP 14, 94403 Vitry-sur-Seine Cedex, France

Abstract

3,4-Dihydro-8-trifluoromethoxy-1,2,4-thiadiazino[3,4-b]benzothiazole (2) was prepared in five steps from 6-trifluoromethoxy-2-benzothiazolamine (riluzole, 1). The key final step consisted of an original N-S bond forming reaction between unsubstituted imine and thiol groups, using chloramine-T as reagent (75% yield).

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2753-2764
Published online:
DOI: 10.3987/COM-93-6500
Synthesis of Various Pyrido- and Indolo[g]fused 1H-Quinolin-4-one Derivatives

Jacqueline Moron,* Christiane Huel, and Emile Bisagni

*URA 1387 CNRS,Synthése organique, Section de Biologie Batiments 110-112, Institut Curie, 15 Rue Georges Clemenceau 91405 Orsay, France

Abstract

Four series of linear tricyclic and quadricyclic heterocyclic derivatives related to oxolinic acid have been prepared: 1H-pyrido[3,4-g]quinolin-4-ones (1), 1H-pyrido[3,2-g]quinolin-4-ones (2), 1H,11H-pyrido[3,2-b]acridine-4,6-diones (8) and 1H,10H-indolo[3,2-g]quinolin-4-ones (10).

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2765-2776
Published online:
DOI: 10.3987/COM-93-6503
Furanoid Glycal as a Starting Material for Nucleoside Derivatives

Hiroshi Kawakami,* Takashi Ebata, Koshi Koseki, Koji Okano, Katsuya Matsumoto, and Hajime Matsushita

*Life Science Research Laboratory, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan

Abstract

Furanoid glycal was utilized as a starting material for the nucleoside derivatives with the aid of benzenesulfenyl chloride. Condensation reaction with silylated nucleic bases ws high in the presence of SnCl4. Electrophilic addition of benzenesulfenyl chloride to the glycal with substituent also proceeded in high stereoselectivity. Phenylthio-substituted nucleoside was used to convert 2’,3’-dedeoxynucleoside and 2’,3’-didehydro-2’,3’-dideoxynucleoside.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2777-2782
Published online:
DOI: 10.3987/COM-93-6511
An Asymmetric Synthesis of (+)-Indolizidine 195B

Hiroki Takahata,* Hiroshi Bandoh, and Takefumi Momose*

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan

Abstract

An asymmetric synthesis of (+)-indolizidine 195B (1) starting from the known pyrrolidino alcohol (2) available from L-norleucine has been achieved.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2783-2804
Published online:
DOI: 10.3987/COM-93-6514
A Synthesis Method of Indole-3-methanamine and/or Gramine from Indole-3-carboxaldehyde, and Its Application for the Synthesis of Brassinin, Its 4-Substituted Analogs, and 1,3,4,5-Tetrahydropyrrolo[4,3,2-de]quinoline

Fumio Yamada, Kensuke Kobayashi, Aya Shimizu, Naokatsu Aoki, and Masanori Somei*

*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

Simple conversion method of indole-3-carboxaldehyde into gramine and/or indole-3-methanamine was developed. The present method realized short step syntheses of brassinin, 4-iodo-, methoxy-, 4-methoxy-, and 4-nitrobrassinin, 4-methoxyindole-3-acetonitrile, and 1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinoline.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2805-2810
Published online:
DOI: 10.3987/COM-93-6524
C-Nucleosides. 23. Synthesis of Enaminone Glycoside and 4-(β-D-Ribofuranosyl)quinoline-2-carboxamide from Furanone Glycoside

Isamu Maeba,* Yasutaka Ito, Masakazu Wakimura, and Chihiro Ito

*Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku, Nagoya 468-8503, Japan

Abstract

Furanone glycoside (1) was treated with aniline to yield 3-anilino-5-hydroxy-5-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)furan-2(5H)-one (2). Reaction of 2 with trifluoroacetic acid afforded enaminone glycoside (3), whereas treatment of 2 with hydrochloric acid in methanol brought about the ring formation to furnish methyl 4-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)quinoline-2-carboxylate (6) together with methyl 2-anilino-4-(3,5-di-O-benzoyl-1,4-anhydro-2-deoxy-D-erythropent-1-enofuranosyl)-4-oxobutanoate (4) and methyl 2-anilino-4-(5-benzoyloxymethylfuran-2-yl)-4-oxobutanoate (5) in yields of 12%, 12%, and 7%, respectively. The quinoline ester (6) reacted with aq. ammonia in methanol to produce quinolinecarboxamide C-nucleoside (7).

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2811-2818
Published online:
DOI: 10.3987/COM-93-6525
Reaction of Trifluoroacetic Anhydride with N-(2-Hydroxybenzyl)-α-amino Acids: An Entry in the New [1,3]Oxazolo[2,3-b][1,3]benzoxazine Ring System

Bernard Chantegrel, Christian Deshayes,* and René Faure

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

Abstract

The diastereospecific double ring closure of N-(2-hydroxybenzyl)-α-amino acids with trifluoroacetic anhydride leads to the formation of 10a-trifluoromethyl-2,3,4,10a-tetrahydro[1,3]oxazolo[2,3-b][1,3]benzoxazin-2(5H)-ones. The chemical structures are supported by ir, 1H-nmr and 13 C-nmr spectra and X-ray analysis.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2819-2828
Published online:
DOI: 10.3987/COM-93-6529
Furan Ring Opening Reactions of 5-Hydroxy-2,3-dihydrobenzo[b]furans

Jaime A. Valderrama,* M. Florencia González, Patricia Arias, Hernán Pessoa-Mahana, and Ricardo Tapia

*Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago-22, Chile

Abstract

A furan ring opening of benzo[b]furans (1a-c) under acetylation and methylation conditions was carried out. The reaction of these heterocycles with acetic anhydride-pyridine mixture afforded the corresponding 1,4-disubstituted buta-1,3-dienes (3a-c). Compound (3c) reacts with dimethyl sulfate under basic conditions to give 1-methoxy-4-(3,6-dimethoxy-2-nitrophenyl)-buta-1,3-diene (5) in 95% yield. Some evidences on the participation of carbanion intermediates and a possible reaction course for the furan ring opening of heterocycles (1a-c) are presented.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2829-2837
Published online:
DOI: 10.3987/COM-93-6534
Simple Synthesis of Polyfunctional Nitropyridines

Maria Teresa Cocco,* Cenzo Congiu, and Valentina Onnis

*Dipartimento Farmaco Chimico Tecnologico, Università digli Studi di Cagliari, Via Ospedale 72, I-09124, Cagliari, Italy

Abstract

Upon treatment with nitroketene dithioacetal (2) in refluxing acetonitrile, enaminonitriles (1) afforded nitrodienamines (3). Polysubstituted nitropyridines (4 and 5) were obtained by cyclization of intermediates (3) with orthoformate and acetic anhydride respectively.

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Paper | Regular issue | Vol 36, No. 12, 1993, pp.2839-2850
Published online:
DOI: 10.3987/COM-93-6535
Synthesis and Reactions of N-Substituted Pyrazolo-3-sulfolenes

Ta-shue Chou* and Ruei-Chih Chang

*Institute of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei 11529, Taiwan, R.O.C.

Abstract

N-Toluenesulfonyl- and N-(anilinocarbonyl)pyrazolo-3-sulfolenes have been prepared from the protected oxotetrahydrothiophenecarbaldehyde (7) via a sequence of hydrazone formation, ketal hydrolysis, cyclization, dehydration, and oxidation reactions. These N-substituents migrate between the two nitrogen atoms of the pyrazole ring at different stages. Extrusion of SO2 from N-anilinocarbonylpyrazolo-3-sulfolenes was achieved at 180-200 °C and the transient intermediate, the pyrazolo-o-quinodimethane, could be trapped with dienophiles.

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21 data found. 1 - 21 listed