Regular Issue

Vol. 45, No. 8, 1997

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 45, No. 8, 1997, pp.1433-1439
Published online:
DOI: 10.3987/COM-97-7795
Palladium Catalysed Cross Coupling of Phenylsulphonylglucals with Aryl Halides

Cedric W. Holzapfel* and Madrie Portwig

*Department o f Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland Park, 2006, Johanesberg, South Africa

Abstract

The lithiation of a number of 2-phenylsulphonylglucals and the resulting 2-arylglucals formed by subsequent Negishi cross coupling with simple aryl halides and desulphonation is described.

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Communication | Regular issue | Vol 45, No. 8, 1997, pp.1441-1446
Published online:
DOI: 10.3987/COM-97-7844
Synthesis of 1,3-Linked 1,4-Dihydro-pyridines Containing the L-Tyrosine Residue and the Influence of Their Structures upon the Enantioselective Reduction

Akira Katoh,* Shoichiro Naruse, Junko Ohkanda, and Hiroshi Yamamoto

*Department of Industrial Chemistry, Faculty of Engineering, Seikei University, Musashino-shi, Tokyo 180-8633, Japan

Abstract

Novel 1,3-linked chiral 1,4-dihydropyridines (5a-c) bearing the L-tyrosine residue and the long alkyl chains have been synthesized. The ring size gave a large influence upon the enantioselective reduction of methyl benzoylformate, where 1,12-oxo-2,20-diaza-3-methoxycarbonyl-11-oxa-20,23-dihydro[4,9]metaparacyclophane (5b) showed the highest enantiomer excess (ee, 70%). Further, the 1,3-cyclic structure (5) was demonstrated to be effective on the enantioselective reduction compared to the corresponding acylic one (7), N-(1-propyl-1,4-dihydro-3-pyridylcarbonyl)-L-(O-pentanoyl)tyrosine methyl ester.

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Communication | Regular issue | Vol 45, No. 8, 1997, pp.1447-1450
Published online:
DOI: 10.3987/COM-97-7845
The Novel Synthesis of 5-Cyano-1-azabicyclo[3.3.0]octane

Mituru Oka, Yukiharu Matsumoto,* and Ryoichi Unno

*Drug Discovery Research Department, Sanwa Kagaku Kenkyusho, 363 shiosaki, Hokusei-cho, Inabe-gun, Mie, 511-04, Japan

Abstract

5-Cyano-1-azabicyclo[3.3.0]octane (1), which is a key intermediary material to some medicines, was prepared from 1,7-dichloroheptan-4-one (7) via only one step under mild conditions. The reaction mechanism is also discussed.

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Communication | Regular issue | Vol 45, No. 8, 1997, pp.1451-1455
Published online:
DOI: 10.3987/COM-97-7849
Asymmetric Synthesis with Chiral Hydrogenolysable Amines : A New Route to Enantiomerically Pure Amino Diols

Fabienne Segat, Olivier Lingibé, Bernadette Graffe, Marie-Claude Sacquet, and Gérard Lhommet*

*Université P. et M. Curie, Laboratoire de Chimie des Hétérocycles URA 408, 4, Place Jussieu - case 43 F-75252 Paris Cedex 05, France

Abstract

Enantiomerically pure amino diols are obtained via diastereoselective reduction of chiral enamino and imino esters (3a), (3b), and (3c).

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Communication | Regular issue | Vol 45, No. 8, 1997, pp.1457-1461
Published online:
DOI: 10.3987/COM-97-7850
Synthesis and Properties of N,N',N''-Tris(1-naphthylmethyl)-1,5,9-triazacyclododecane

Kanji Kubo,* Emi Yamamoto, and Tadamitsu Sakurai

*Departmnet of Applied Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan

Abstract

N,N’-Bis(1-naphthylmethyl)piperazine and N,N’,N’’-tris(1-naphthylmehyl)-1,5,9-triazacyclododecane were found to display unique photophysical properties for the guest salts. These guest salts enhanced the host emission remarkably by the inhibition of intramolecular exciplex formation and then quenched the emission by photoinduced electron transfer from the counter anion to the naphthalene chromophore in the presence of high concentrations of the salts.

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Communication | Regular issue | Vol 45, No. 8, 1997, pp.1463-1466
Published online:
DOI: 10.3987/COM-97-7856
Syntheses of 5-Arylpyrazole Derivatives via Palladium-catalyzed Cross-Coupling Reactions

Kazuo Yagi,* Tomoyuki Ogura, Akira Numata, Shigeru Ishii, and Kazutaka Arai

*Central Research Institute, Nissan Chemical Industries Ltd., 722-1 Tsuboicho, Funabashi, Chiba 274-8507, Japan

Abstract

The first examples of a direct introduction of an aryl group onto a pyrazole ring via palladium-catalyzed cross-coupling reactions are reported. It was found that substituents at 1-position on the pyrazole ring affected the yields, and dimethylsulfamoyl group, as an electron-withdrawing group, gave highest yield.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1467-1475
Published online:
DOI: 10.3987/COM-97-7735
Studies in Sigmatropic Rearrangement of 3-(4-Aryloxybut-2-ynyloxy)-1-methylquinolin-2-ones: Synthesis of 3H-Pyrano[2,3-c]quinolin-5(6H)-ones and Furo[2,3-c]quinolin-4(5H)-ones

Krishna C. Majumdar* and Anup K. Kundu

*Department of Chemistry, University of Kalyani, Kalyani-741 325, W. B., India

Abstract

3-(4-Aryloxybut-2-ynyloxy)-1-methylquinolin-2-ones (3), in refluxing chlorobenzene, gave 1-aryloxymethyl-6-methyl-3H-pyrano[2,3-c]quinolin-5(6H)-ones (4) and/or, 1-aryloxymethyl-2,5-dimethylfuro[2,3-c]quinolin-4(5H)-ones (5). The base or the radical initiator (azoisobutyronitirle) does not seem to have any effect on the formation of the products. Substrates (3) provided only products (5) in the presence of toluene-4-sulphonic acid. All the substrates (3) studied so far underwent sigmatropic rearrangements at the 4-quinolin-3-ynyoloxypropynyl function of compound (3) to give products (4) and/or (5).

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1477-1492
Published online:
DOI: 10.3987/COM-97-7772
Novel Double Tripodal Pyrazolyl Macrocycles. Synthesis and X-Ray Structure of Hexa-Azole Ligands

Johan E. Bol, Bas Maase, Gianella Gonesh, Willem L. Driessen,* Kees Goubitz, and Jan Reedijk

*Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O.Box 9502, Einsteinweg 55, 2300 RA Leiden, The Netherland

Abstract

The synthesis and characterization of two new hexa-azole macrocyclic ligands, MEPY22PZ and ETPY24PZ, are described. The single crystal structure of ETPY24PZ shows two metal-binding sites with a tripodal N4 geometry. Coordination of 2 Cu(I) or 2 Zn(II) ions by each macrocycle by NMR complexation studies.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1493-1507
Published online:
DOI: 10.3987/COM-97-7788
Synthesis of 5(10→9)abeo-Ergolines

Sergio Mantegani,* Emanuele Arlandini, Daniela Borghi, Enzo Brambilla, and Mario Varasi

*Pharmacia & Upjohn, C.N.S. Research, Viale Pasteur 10-20014 Nerviano (Milan), Italy

Abstract

Reaction of the (5R,8R)-ergoline derivative (6) with the couple CCl4/(Ph)3P unexpectedly resulted in the formation of the novel (5S,8R)-5 (10 → 9)abeo-ergoline derivative. A mechanism of this transposition process is proposed.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1509-1518
Published online:
DOI: 10.3987/COM-97-7823
Syntheses of New Pyrazolo[3,4-d]-pyrimidine Derivatives Starting from 1,1-Diamino-2,2-dicyanoethylene

Richard Neidlein* and Zhijun Wang

*Pharmazeutisch-Chemishces Institut, Universität Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany

Abstract

3,4-Diamino-6-dimethylamino-1-methylpyrazolo[3,4-d]pyrimidine (4) was prepared from the reaction of 6-amino-4-choro-5-cyano-2-dimethylaminopyrimidine (3) with methylhydrazine. It reacted further with different aldehydes giving a variety of new pyrazolo[3,4-d]pyrimidine derivatives.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1519-1528
Published online:
DOI: 10.3987/COM-97-7829
Synthesis of Various Substituted Nitroisoquinolines by SRN1 Methodology

Patrice Vanelle,* Pascal Rathelot, José Maldonado, and Michel P. Crozet

*Laboratoire de Chimie Organique, Faculté de Pharmacie, Université de la Méditerranée, 27, Boulevard Jean Moulin, 13385 Marseille Cedex 05, France

Abstract

The versatile SRN1 methodology allows straightforward access to new 1-substituted 5-nitroisoquinolines from an original heterocyclic reductive alkylating agent, 1-chloromethyl-5-nitroisoquinoline, with various nitronate anions. By base-promoted nitrous acid elimination, trisubstitued olefins are prepared from the C-alkylation derivatives.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1529-1536
Published online:
DOI: 10.3987/COM-97-7830
Formation of 3-Iso-19-epicathenamine, Isolated as Its Cyano Adduct 21α-Cyano-3-isorauniticine

Mauri Lounasmaa* and Pirjo Hanhinen

*Laboratory for Organic and Bioorganic Chemistry, Technical University of Helsinki, P.O. Box 6100, FIN-02150 HUT Espoo, Finland

Abstract

Formation of 3-iso-19-epicathenamine (8), which is a plausible intermediate in the biogenetic formation of heteroyohimbine alkaloids 3-isorauniticine (11) and 3-iso-19-epiajmalicine (12), is described. Compound (8) was isolated as its cyano adduct, 21α-cyano-3-isorauniticine (17). The Brown and Leonards’ 21-cyano adduct, isolated after a biomimetic conversion process of a mixture of strictosidine (18) and vincoside (19), and for which the 21α-cyanoakuammigine structure (21) was claimed, is shown to be in reality identical with compound (17).

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1537-1549
Published online:
DOI: 10.3987/COM-97-7836
The Synthesis of Oxa-Analogs of the Kainoid Family

Hansruedi Baumgartner, Anthony C. O'Sullivan,* and Josef Schneider

*Preclinical Research, Novartis Pharma AG, S.350/315, CH-4002 Basel, Switzerland

Abstract

In an effort to mimic the anthelmintic and insecticidal activities of kainic acid (1) and domoic acid (2) with compounds of simpler structure and much easier accessibility, the highly functionalised isoxazolidines (4) and (20) were prepared.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1551-1557
Published online:
DOI: 10.3987/COM-97-7847
Ring Transformation of Fused Pyridazines. VI. Construction of 3-(2-Pyridyl)indole Skeleton by Means of N-N Bond Cleavage Reaction of Fused Pyridazines with Ynamines

Ken-ichi Iwamoto,* Etsuo Oishi, Tomonobu Sano, Ayako Tsuchiya, Yumiko Suzuki, Takeo Higashino, and Akira Miyashita

*Schol of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan

Abstract

We established a new N-N bond cleavage reaction of pyridazino[4,5-b]indoles with ynamines to form 3-(2-pyridyl)indoles. The latter are easily converted to 3-(2-piperidyl)indoles, which are key intermediates for the synthesis of indole alkaloids.

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Paper | Regular issue | Vol 45, No. 8, 1997, pp.1559-1566
Published online:
DOI: 10.3987/COM-97-7854
Constituents of the Seeds of Garcinia kola : Two New Antioxidants, Garcinoic Acid and Garcinal

Kenji Terashima, Tomoyuki Shimamura, Miho Tanabayashi, Mohammad Aqil, John A. Akinniyi, and Masatake Niwa

*Faculty of Pharmacy, Meijo University, 150 Yagoto, Tempaku-ku, Nagoya, Aichi 468-8503, Japan

Abstract

Two new chromanols, named garcinoic acid and garcinal, were isolated together with a known chromanol, δ-tocotrienol and three known biflavonoids, garcinianin, GB-1 and GB-2, from the seeds of Garcinia kola Heckel (Guttiferae) collected in Nigeria and their structures were characterized on the basis of the spectroscopic and chemical evidence. Garcinoic acid, garcinal and δ-tocotrienol showed about 1.5 times stronger antioxidation activity than that of dl-α-tocopherol.

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Note | Regular issue | Vol 45, No. 8, 1997, pp.1567-1572
Published online:
DOI: 10.3987/COM-97-7826
1,3-Dipolar Cycloadditions of Polycyclic Aromatic Hydrocarbons with Nitrile Oxides under Microwave Irradiation in the Absence of Solvent

Antonino Corsaro,* Ugo Chiacchio, Vito Librando, Salvatore Fisichella, and Venerando Pistarà

*Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, I-95125 Catania, Italy

Abstract

In title cycloadditions microwave irradiation improves product yields and reduces dramatically reaction times in comparison with classical heating with and without refluxing solvents. In the double cycloaddition of nitrile oxides to anthracene a selectivity in favour of unsymmetrical bis-cycloadduct is observed.

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Note | Regular issue | Vol 45, No. 8, 1997, pp.1573-1578
Published online:
DOI: 10.3987/COM-97-7838
First Isolation and Determination of Three Humulene Triepoxides

Kiyoharu Hayano* and Katsura Mochizuki

*Chemistry Laboratory, Hokkaido College of Education, Ainosato, Sapporo, Hokkaido 002-8502, Japan

Abstract

The epoxidation of (9E)-(2R*, 3R*, 6R*, 7R*)-2,3;6,7-diepoxy-3,7,11,11-tetramethylcycloundec-9-ene (1TC) with m-CPBA gave two triepoxides, (2R*, 3R*, 6R*, 7R*, 9S*, 10S*)- and (2R*, 3R*, 6R*, 7R*, 9R*, 10R*)-2,3;6,7;9,10-triepoxy-3,7,11,11-tetramethylcycloundecane (3 and 4), in the ratio of 3 : 4 = 52 : 48. The epoxidation of (9E)-(2S*, 3S*, 6R*, 7R*)-2,3;6,7-diepoxy-3,7,11,11-tetramethylcycloundec-9-ene (2CT) gave only one triepoxide, (2S*, 3S*, 6R*, 7R*, 9S*, 10S*)-2,3;6,7;9,10-triepoxy-3,7,11,11-tetramethylcycloundecane (5). The configurations for 4 and 5 were determined by X-Ray crystallogrphy.

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Note | Regular issue | Vol 45, No. 8, 1997, pp.1579-1588
Published online:
DOI: 10.3987/COM-97-7839
Preparation of Fused Thiadiazolo- and Imidazobenzothiazoles from 2-Amino-benzothiazoles. Their Fungicidal Acitivity

Yoo Tanabe,* Akiyuki Kawai, Yoshihiro Yoshida, Masahiro Ogura, and Hitomi Okumura

*School of Science, Kwansei Gakuin University, 1-1-155 Uegahara, Nishinomiya 662-8501, Japan

Abstract

A regioselective [2+3] cyclocondensation between chlorocarbonylsulfenyl chloride (3) and 2-aminobenzothiazoles gave 3H-1,2,4-thiadiazolo[3,4-b]benzothiazol-3-ones (1). Some heterocycles (1) and their isosteric known 5-substituted 2-methylimidazo[2,1-b]benzothiazoles (2) which were prepared from 2-aminobenzothiazoles via two steps, showed significant fungicidal activities.

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Note | Regular issue | Vol 45, No. 8, 1997, pp.1589-1592
Published online:
DOI: 10.3987/COM-97-7855
Studies on Isocyanides and Related Compounds. A Novel Synthetic Route to 1,6-Dihydro-6-oxopyridine-2-carboxylic Acid Derivatives

Ricardo Bossio, Carlos F. Marcos, Stefano Marcaccini,* and Roberto Pepino

*CNR, Centro di Studio Sulla Chimica e la Struttura dei Composti Eterociclici e lolo Applicazioni, c/o Dipartimento di Chimica Organica "Ugo Schiff", Università di Firenze, Via Gino Capponi 9, I-50121 Firenze, Italy

Abstract

The Ugi 4-CC between (E)-cinnamaldehyde (2), benzoylformic acid (3), cyclohexyl isocyanide (4) and amines (5) afforded the expected (E)-2-[N-benzoylformyl-N-arylamino]-4-phenylbut-3-enoic acid N-cyclohexylamides (6) which underwent a base-catalyzed cyclization to give the title compounds in high yields.

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Note | Regular issue | Vol 45, No. 8, 1997, pp.1593-1600
Published online:
DOI: 10.3987/COM-97-7864
A Convenient Method for the Synthesis of 9-Aryl-4-methoxynaphtho[2,3-c]furan-1(3H)-ones

Kazuhiro Kobayashi,* Yasuhiro Kajimura, Kouji Maeda, Tomokazu Uneda, Osamu Morikawa, and Hisatoshi Konishi

*Department of Materials Science, Faculty of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

A three-step procedure for the synthesis of the title lignan lactone derivatives is described. The route involves a tandem Michael addition/cyclization reaction between o-aroyl-α-methoxybenzyllithiums, which are generated in situ by the treatment of aryl 2-methoxymethylphenyl ketones with lithium diisopropylamide (LDA) in THF at -78 °C, and furan-2(5H)-one to give the corresponding 9-aryl-9-hydroxy-4-methoxy-3a,4,9,9a-tetrahydronaphtho[2,3-c]furan-1(3H)-ones in moderate to good yields. These products are readily transformed into the title naphthofuranones by dehydration with thionyl chloride in pyridine, followed by aromatization with palladium on activated carbon.

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20 data found. 1 - 20 listed