Regular Issue

Vol. 41, No. 6, 1995

16 data found. 1 - 16 listed
Communication | Regular issue | Vol 41, No. 6, 1995, pp.1127-1130
Published online:
DOI: 10.3987/COM-95-7066
A New Mode for the Formation of Endocyclic Double Bond from the Selenonium Salt of 1,11-Methanoselenomethano-5H,7H-dibenzo[b,g][1,5]diselenocin: Synthesis of Methanoselenomethano-bridged Dibenzo[b,f]selenepin

Hisashi Fujihara,* Tsukasa Nakahodo, Hisatomo Mima, and Naomichi Furukawa*

*Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki, 305, Japan

Abstract

Benzylic selenonium salt of 1,11-methanoselenomethano-5H,7H-dibenzo[b,g][1,5]diselenocin was treated with tert-BuOK to give the corresponding Stevens-type rearrangement product which was converted into a new heterocyclic compound, 1,11-ethano-5H,7H-dibenzo[b,g][1,5]diselenocin (4), upon treatment with m-chloroperbenzoic acid. The conformational property of 4 is described.

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Communication | Regular issue | Vol 41, No. 6, 1995, pp.1131-1134
Published online:
DOI: 10.3987/COM-95-7068
A General and Efficient Synthesis of Optically Pure S-Arylmercapturates

Shizuo Nakamura*, Mitsuyoshi Kondo, Kiyoto Goto, Shinsaku Naito, Yoshiaki Tsuda, and Kozo Shishido*

*Institute for Medicinal Resources, University of Tokushima, Sho-machi 1, Tokushima 770, Japan

Abstract

Optically pure S-arylmercapturate derivatives (4a-d) were efficiently synthesized via the reaction of Boc-L-Ser-OMe (6) with a variety of disulfides (5a-d) in the presence of tri-n-butylphosphine. The procedure was successfully applied to the synthesis of the enantiomerically pure S-thienylmercapturic acid (2), a metabolite of antiinflammatory drug DUP697 (1).

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Communication | Regular issue | Vol 41, No. 6, 1995, pp.1135-1138
Published online:
DOI: 10.3987/COM-95-7072
INOC Reaction in Gibberellin Synthesis - A Practical Synthesis of the Key Intermediate for Gibberellin A12

Masahiro Toyota, Toshihiro Wada, and Keiichiro Fukumoto*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-77, Japan

Abstract

The isoxazoline (10), a possible key intermediate for gibberellin A12 (1), has been synthesized in 91% yield by means of intramolecular nitrile oxide cycloaddition (INOC) reaction of the oxime (9).

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1139-1168
Published online:
DOI: 10.3987/COM-94-6975
Intramolecular Cyclization with Oxocarbenium Ion. Synthesis of 1-Azabicyclo[3.3.1]nonene and [3.2.1]octene Derivatives

Sándor Sólyom*, Gizella Ábrahám, Márta Szöllõsy, István Pallagi, Emese Csuzdi, István Ling, Beáta Vitális, Katalin Horváth, Edit J. Horváth, László G. Hársing Jr., and Judit Kajtár

*Institute for Drug Research Ltd., H-1325 Budapest, P.O.B. 82, Hungary

Abstract

Hydroxy- and aryl-substituted 1-azabicyclo[3.3.1]nonene and [3.2.1]octene derivatives have been synthesized by the intramolecular cationic cyclization of 4-aryl-1,2,5,6-tetrahydropyridines bearing an acetal moiety in the nitrogen substituent. Factors governing the stereoselectivity of the ring closure step have been disclosed. Two compounds were resolved into the enantiomers and the absolute configuration of one of them was deduced from CD investigations. Among the new compounds substances with valuable antiamnesic effect have been found.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1169-1179
Published online:
DOI: 10.3987/COM-94-6999
Diels-Alder Reactions of a Hydrazonocrotonate with Bromonaphthoquinones

Leila Chaker, Félix Pautet, and Houda Fillion*

*Laboratoire de Chimie Organique, Institut des Sciences Pharmaceutiques et Biologiques, Université Claude Bernard, 8 avenue Rockefeller, 69373 Lyon Cedex 08, France

Abstract

An efficient and regiospecific synthesis of 4,6- and 4,9-disubstituted 5,10-benzo[g]quinolinequinone derivatives was performed through a hetero Diels-Alder reaction between methyl (E)-4-dimethylhydrazono-2-butenoate (1) and 2- or 3-bromo-5-substituted naphthoquinones (2) and (3). According to the experimental conditions used, the corresponding dihydro or aromatic compounds were isolated as the major products. The regiochemistry of the cycloadditions is governed by the position of the bromine atom C-2 or C-3 of the quinone.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1181-1196
Published online:
DOI: 10.3987/COM-94-7005
Synthesis of Designed Functional Models of Bleomycin Incorporating Imidazole - containing Lexitropsins as Novel DNA Recognition Sites

Liren Huang and J. William Lown*

*Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 Canada

Abstract

Synthesis and characterization of compounds 1a - d, designed functional models for the antitumor antibiotic bleomycin, in which AMPHIS serves as the metal complexing subunit, chiral 1,2-trans-disubstituted cyclopropane as linkers and imidazole-containing lexitropsins as DNA sequence selective binding sites, are described.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1197-1206
Published online:
DOI: 10.3987/COM-94-7007
Mechanism of Formation of Fluorescent Adenosine Analogues

Richard F. de Boer, Daniëlle G. I. Petra, Marin J. Wanner, Aldo Boesaart, and Gerrit-Jan Koomen*

*Laboratory of Organic Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands

Abstract

During studies towards the synthesis of a transition state inhibitor of the enzyme adenylosuccinate lyase, two different pyrimido[2,1-i]purines were found, depending on the reaction conditions. It was shown that one of the products, formed under kinetically controlled reaction conditions can be converted in the thermodynamically more stable one via a Dimroth type rearrangement. The latter isomer shows strong fluorescent properties in the uv/vis region, which makes it potentially useful as a fluorescent probe in biological studies.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1207-1218
Published online:
DOI: 10.3987/COM-95-7024
Preparation of Homologous Pyrazolonedicarboxylates

Janja Makarevic* and Vinko Skaric

*Laboratory of Stereochemistry and Natural Products, "Ruder Boskovic" Institute, 41001 Zagreb, P.O. B. 1016, Croatia

Abstract

Homologous disodium pyrazolonedicarboxylates (8, 16f and 16g) as possible protecors of cis-DDP induced nephrotoxicity, have been prepared by the reaction of hydrazine with di-t-butyl ethyl β-keto triesters (5b, 13b and 13c) and subsequent hydrolysis of formed di-t-butyl pyrazolonedicarboxylates (6b, 14b and 14c).

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1219-1233
Published online:
DOI: 10.3987/COM-95-7030
6-(N-Imidoalkyl)aminoalkylbenzothiazolin-2-ones as Ligands of the Serotoninergic 5-HT1A Receptors

Ousmane Diouf, Patrick Depreux, Daniel Lesieur, Jacques H. Poupaert,* and Daniel H. Caignard

*Ecole de Pharmacie, Université Catholique de Louvain, Avenue E. Mounier 73, B-1200 Bruxelles, Belgium

Abstract

A synthesis of 6-(N-imidoalkyl)aminoalkylbenzothiazolin-2-ones, during which it was necessary to prepare the corresponding 3-methyl-6-(n-N-methylaminoalkyl)benzothiazolin-2-ones using as key intermediates the suitable trifluoromethylalkyl derivatives, is described. This approach allowed access to monomethylated seconary amines which were then reacted with the bromoalkylimides to give the title compounds. All these compounds possess a common alkylimido linking group which was flanked by a 3-methylaminoalkylbenzothiazolin-2-one moiety. The variation of the number of methylene groups linking the central basic nitrogen to the benzothiazolin-2-one and to the imido group as well as the nature of the imido group were studied to delineate the structure-affinity relationships of this series.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1235-1250
Published online:
DOI: 10.3987/COM-95-7042
Reactions of 1,3-Dithietane-2,4-diylidenebis(cyanoacetic Acid Alkyl Esters) and 2-Cyano-3,3-bis(methylsulfanyl)acrylic Acid Ethyl Ester

Monika Jochheim, Harald G. Krug, Richard Neidlein,* and Claus Krieger

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

Abstract

1,3-Dithietanes (1) react with carboxylic acid hydrazides (2) yielding substituted 1,3,4-oxadiazoles (3). The treatment of compound (1) with 5-phenylpyrazolidin-3-one (4) resulted in 5H-pyrazolo[5,1-b][1,3]thiazines (5). Pyrazoles (7) can be obtained by the reaction of ketene-S,S-acetals (6) with carboxylic acid hydrazides.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1251-1269
Published online:
DOI: 10.3987/COM-95-7043
Acid Catalyzed Reactions of 2-Vinylaniline Derivatives with Cyclic Ketones of the Tetralone-, Chroman-4-one- and 2,3-Dihydro-1H-quinolin-4-one Series. New N(O)-Heterocycles via 6π-Electrocyclic Rearrangements or [1,5] Dipolar Electrocyclizations. Part 3

Harald Walter* and Josef Schneider

*Division Crop Protection Research and Development Disease Control, Ciba-Geigy Limited, Postfach, CH-4002 Basel, Switzerland

Abstract

The reaction of several 2-vinylaniline derivatives with α-tetralone, chroman-4-one and 2,3-dihydro-1-methyl-1H-quinolin-4-one at temperatures between 110 and 115 °C with toluene-4-sulfonic acid as catalyst was studied. A series of polycyclic cyclobut[1,2-b]indoles, cyclobut[1,2-c]chromans, cyclobut[1,2-c]quinolines and spirocyclic 1H(1’H)quinolines was obtained in moderate to very good yields. Mechanistical details as well as scope and limitations of the new method are discussed.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1271-1274
Published online:
DOI: 10.3987/COM-95-7054
Alkylation of 5-Cyanoimidazole-4-carboxamide

Peter K. Bridson* and Rekha V. Iyengar

*Department of Chemistry, The University of Memphis, Memphis, TN 38152, U.S.A.

Abstract

Alkylation of 5-cyanoimidazole-4-carboxamide under alkaline conditions occurs with extremely high regioselectively at the nitrogen atom adjacent to the cyano group. The reaction is demonstrated to be useful for the synthesis of imidazo[1,5-a]pyrazines.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1275-1290
Published online:
DOI: 10.3987/COM-95-7055
Direct Introduction of Acyl and Ethoxycarbonyl Groups into Pyrimidine Ring through the Trimethylstannyl Derivatives

Yutaka Yamamoto,* Hidekazu Ouchi, Takuo Tanaka, and Yasuo Morita

*Tohoku College of Pharmacy, 4-1, Komatsushima 4 Chome, Aoba-ku, Sendai 981, Japan

Abstract

The reactions of acylformyl chlorides with 2- and 4-rimethylstannylpyrimidine derivatives proceeded more smoothly than those of acyl chlorides giving the corresponding 2- and 4-acylpyrimidines. Employing ethyl chloroglyoxylate instead of the acylating agent yielded the ethoxycarbonylpyrimidines. Similarly, the stepwise acylation and ethoxycarbonylation of bis(trimethylstannyl)pyrimidines provided pyrimidines having two different carbon functional groups.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1291-1298
Published online:
DOI: 10.3987/COM-95-7061
Synthesis of 1,2,3,4,5,6-Hexahydropyrrolo[3,4-c]pyrrole Dihydrobromide and 1,2,3,5-Tetrahydro-2-[(4-methylphenyl)sulfonyl]pyrrolo[3,4-c]pyrrole

Heiner Jendralla* and Gerd Fischer

*Hoechst AG, Allgemeine Pharma Forschung, Entwicklungsgruppe Synthese, Postfach 800320, D-65926 Frankfurt, Main 80, Germany

Abstract

Synthesis of the pyrrolo[3,4-c]pyrrole derivatives (8) and (9) is reported. Nucleophilic aromatic substitution of the 7-fluoride of 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (1) by 8 under basic conditions followed by N-methylation, gives the quinolone antibacterial agent (11) (KR 10755, HK 3140).

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1299-1305
Published online:
DOI: 10.3987/COM-95-7062
One-Pot Synthesis of Some Fused Pyran-2-ones

Vladimir Kepe, Marijan Kočevar,* and Slovenko Polanc

*Department of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 61000 Ljubljana, Slovenia

Abstract

A one-pot synthesis of different fused pyran-2-ones starting from some less commonly used activated methylene compounds (cyclic lactones, a thiolactone and a lactam), one-carbon sources and N-acylglycines in acetic anhydride is described.

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Paper | Regular issue | Vol 41, No. 6, 1995, pp.1307-1318
Published online:
DOI: 10.3987/COM-95-7064
Polycyclic N-Heterocyclic Compounds. 46. Synthesis of Thieno[2,3-h][1,6]naphthyridines from 2-(3-Cyanopropylthio)pyridine-3-carbonitrile

Kenji Sasaki, Abu Shara S. Rouf, Setsuo Kashino, and Takashi Hirota*

*Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700, Japan

Abstract

An efficient methodology for the synthesis of thieno[2,3-h][1,6]naphthyridine skeleton via Smiles type rearrangement reaction followed by cyclization is described. Synthesis of its derivatives is also described.

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16 data found. 1 - 16 listed