Regular Issue

Vol. 45, No. 3, 1997

15 data found. 1 - 15 listed
Communication | Regular issue | Vol 45, No. 3, 1997, pp.435-438
Published online:
DOI: 10.3987/COM-97-7734
Synthetic Study Directed toward Novel Multi-Linked Heterocycles1

Masanori Somei,* Yoshikazu Yamada, Keiichi Kitagawa, Katsuko Sugaya, Yayoi Tomita, Fumio Yamada, and Kyoko Nakagawa

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

Abstract

2-Amino-4-(1-methylindol-3-yl)thiazole (11c) has a characteristic nucleophilic nature at the 5-position and add to the 4-position of acetylpyridinium acetate (13) producing 2-acetylamino-5-(1-acetyl-1,4-dihydropyridin-4-yl)-4-(1-methylindol-3-yl)thiazole (1c). Its structure was established by X-ray single crystallographic analysis. Applying the results, simple syntheses of the related tris- (1a-b and 2-8) and tetrakis-linked heterocycles (9) were achieved.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.439-450
Published online:
DOI: 10.3987/COM-96-7609
Total Synthesis of Sinomendine and Its Analogs

De-Min Zhou, Bao-Zhen Yue, Ji-Qiao Cui, Meng-Shen Cai, and Li-He Zhang*

*School of Pharamceutical Sciences, Beijing Medical University, Beijing, 100083, China

Abstract

Sinomendine (1), a good receptor antagonist of angiotensin II and rare oxoaporphine alkaloid isolated from traditional Chinese drug Sinomenium acutum (Thunb.) Rehd. et Wils, was synthesized from a bromobenzylidenetetrahydroisoquinolineenamide precursor (6). Photocyclization of this enamide led to a protected aporphine (7), which could be converted into oxoaporphine (9) and (±)-sinomendine (1) by Fremy’s salt oxidation followed an available Grignard reaction.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.451-465
Published online:
DOI: 10.3987/COM-96-7671
Phase Transfer Catalyzed C- vs O-Alkylation of 3-Methyl-1-phenyl-2-pyrazolin-5-one in the Absence or Presence of Carbon Disulphide

Mohamed Ali Hassan* and Dietrich Döpp

*Department of Chemistry, Faculty of Science, Ain Shams University, Abbassiya 11566, Cairo, Egypt

Abstract

3-Methyl-1-phenyl-2-pyrazolin-5-one (1) was treated with differenet bromoorganic compounds such as benzyl bromide, 1,3-dibromopropane, methyl bromoacetaldehyde diethylacetal as alkylating agents either in the absence or in the presence of carbon disulphide and under phase-transfer catalysis conditions aimed at studying the reactivity of the title compound with respect to C- vs O-alkylation.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.467-474
Published online:
DOI: 10.3987/COM-96-7686
Novel Pentacyclic π-Conjugated Cations Containing Both Heteroaromatic Units and a Tropylium Ion 2. Synthesis of Cyclohepta[a]benzofuro[c]naphthalenylium and Cyclohepta[a]benzothieno[c]-naphthalenylium Ions

Kimiaki Yamamura,* Taihei Yamane, Hideki Takagi, and Hideyoshi Miyake

*Department of Chemistry, Faculty of Science, Kobe University, Nada-Ku, Kobe 6557-8501, Japan

Abstract

TTwo isomeric pairs of cyclohepta[a]benzofuro[c]naphthalenylium ions (5 and 7) and cyclohephta[a]benzothieno[c]naphthalenylium ions (10 and 11) have been synthesized by an intramolecular Friedel-Crafts type reaction of o-benzofurylcycloheptatrienylbenzenes (3 and 8) and o-benzothienylcycloheptatrienylbenzenes (14 and 15), respectively, in a one-pot reaction.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.475-481
Published online:
DOI: 10.3987/COM-96-7688
Synthesis of Isovincadine and 16-Epiisovincadine, Analogs of Vincadine and 16-Epivincadine with a New Rearranged Skeleton, from a Vincadifformine Derivative

Guy Lewin* and Corinne Schaeffer

*Laboratoire de Pharmacognosie, Faculté de Pharmacie, 5, Rue, Av. J.B. Clément, 92296 Châtenay-Malabry Cedex, France

Abstract

Treatment of the rearranged indole alkaloid (3) under reductive conditions [a) hydrogenolysis; b) NaBH3CN in AcOH] provided 16-epiisovincadine (6) and isovincadine (7), two new rearranged analogs of the alkaloids 16-epivincadine (9) and vincadine (10).

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.483-492
Published online:
DOI: 10.3987/COM-96-7700
3-Amino-2(1H)-quinolones by Cyclizaion of N-Acylated Anthranilic Acid Derivatives

Matthias Rehwald,* Karl Gewald, Hans-Joachim Lankau, and Klaus Unverferth

*Department of Organic Chemistry, Technical University of Dresden, Mommsenstraße 13, D-01062 Dresden, Germany

Abstract

Reaction of secondary amines with the N-(iodoacetyl)anthranilic acid derivatives, 2-(iodoacetylamino)acetophenone and 2-(iodoacetylamino)benzophenone yields 3-amino-2(1H)-quinolones in two steps. Analogously heterocondensed 5-amino-6(7H)-pyrazolo[5,4-b]pyridones were prepared. Hydroxyquinolines were subjected to Cl/OH exchange to give chloroquinolines, which are convenient for consecutive reactions.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.493-500
Published online:
DOI: 10.3987/COM-96-7702
New Syntheses of 2,4-Diaminothiophenes-Use of (1,3-Oxathiol-2-ylidene)-malononitrile

Matthias Rehwald,* Karl Gewald, and Gesine Böttcher

*Department of Organic Chemistry, Technical University of Dresden, Mommsenstraße 13, D-01062 Dresden, Germany

Abstract

Preparation of 2,4-diaminothiophenes using (1,3-oxathiol-2-ylidene)malononitrile as intermediate was achieved.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.501-506
Published online:
DOI: 10.3987/COM-96-7705
Synthesis of 4-[(8-Amino-6-benzyl-10(9H)-oxo-4,5-dihydro-(6H)-isoxazolo[4,3-d]pyrimido[4,5-b]azepin-3-yl]benzoyl-L-glutamic Acid. A Novel Pyrimidoazepine-based Folic Acid Derivative

Michael L. Miller and Partha S. Ray*

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

Abstract

Synthesis of the titled compound (13) is described using an intramolecular 1,3-dipolar cycloaddition reaction as the key step.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.507-525
Published online:
DOI: 10.3987/COM-96-7706
The Conversion of Thioketones to 1,2,4,5-Tetrathianes and Its Mechanism

Rolf Huisgen* and Jochen Rapp

*Institut für Organische Chemie, Universität München, Karlstrasse 23, D-80333 München, Germany

Abstract

TThiobenzophenone and adamantanethione react with sulfur (1:1) under catalysis by sodium thiophenoxide in acetone at rt furnishing 1,2,4,5-tetrathianes (9 and 43) in high yields. An attack of the oligothiolate (R-Sx-) on the C-atom of C=S is proposed as initiating step. Thione S-sulfides (R2C=S+—S-, thiosulfines) cannot be intermediates, since they combine fast with thiones affording 1,2,4-trithiolanes with more sulfur pentathiepane-bis(spiroadamantane) (44) which interconverts with the tetrathiane, but not with the 1,2,4-trithiolane, in an equilibrium catalyzed by R-Sx-. According to 13C NMR evidence, the tetrathiane-bis(spiroadamantane) occurs in a twist conformation which inverts with δG= 16.0 kcal mol-1.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.527-535
Published online:
DOI: 10.3987/COM-96-7709
Synthesis of 7-Amino-4,5,6,7-tetrahydrothieno[3,4-c]pyrid-4-ones

Lan Pham Khanh, Patrick Dallemagne, Abdellah Alsaïdi, and Sylvain Rault*

*Centre d'Etudes et de Recherch sur le Medicament de Normandie, Laboratoire de Pharmaceutiques, 1, rue Vaubenard, 14032 Caen Cedex, France

Abstract

Synthesis of 7-amino-4,5,6,7-tetrahydrothieno[3,4-c]pyrid-4-ones is achieved involving 6-amino-5,6-dihydro-4H-cyclopenta[c]thiophen-4-ones in Beckmann and Schmidt rearrangements.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.537-554
Published online:
DOI: 10.3987/COM-96-7712
Synthesis of New Arylethanolamine and Aryloxypropanolamine Derivatives Including 1,4-Benzodioxine Moiety

Sophie Boyé, Gérald Guillaumet, and Marie-Claude Viaud*

*Institute de Chimie Organique et Analytique, associe au CNRS, Université d'Orléans, B.P. 6759, Rue de Chartres, 45067 Orleans Cedex 2, France

Abstract

The synthesis of new arylethanolamines and aryloxypropanolamines variously substituted on the nitrogen atom are described. Access to these compounds, which are potential β3-adrenergic ligands, involves, as key step, a reductive amination reaction between 2-amino alcohols and 1,4-benzodioxine aldehyde derivatives.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.555-565
Published online:
DOI: 10.3987/COM-96-7713
Reactions of Ethyl (Z)-2-[2,2-Bis(ethoxycarbonyl)vinyl]amino-3-dimethylaminopropenoate with C-Nucleophiles. Synthesis of Substituted 3-Amino-2H-pyran-2-ones

Renata Toplak, Lovro Selic, Gorazd Sorsak, and Branko Stanovnik*

*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, P.O. Box 537, SLO-1000 Ljubljana, Slovenia

Abstract

The reactions of ethyl (Z)-2-[2,2-bis(ethoxycarbonyl)vinyl]amino-3-dimethylaminopropenoate (1) with C-nucleophiles, such as β-keto esters (2, 4, 6), cyclic 1,3-diketones (8a-e), aromatic hydroxy compounds (10, 12, 14, 16 and 18), and heterocyclic hydroxy compounds (20, 22, 24, 26 and 28) gave 2H-pyran-2-ones (3, 5, 7), tetrahydrobenzopyranones (9a-c), benzopyranone (11), naphthopyranones (13, 15, 17 and 19), pyranopyranone (21), pyranobenzopyranone (23), pyranopyridinone (25), pyranoquinolinone (27), and pyranopyridazinone (29) derivatives.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.567-574
Published online:
DOI: 10.3987/COM-96-7718
Novel Preparation and Reaction of N-Benzenesulfonyl- and N-Methanesulfonyltroponimines. New Entry to 1-Azaazulene Derivatives

Tohru Takayasu, Hiroshi Katayama, and Makoto Nitta*

*Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan

Abstract

N-Benzenesulfonyl- and N-methanesulfonyltroponimines were prepared through the reaction of tropone oxime with benzenesulfinyl- and methanesulfinyl chloride. The troponimines reacted with enamines to give formal [8+2] cycloadducts, which subsequently underwent elimination-dehydrogenation sequences to give 1-azaazulene derivatives in modest yields.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.575-584
Published online:
DOI: 10.3987/COM-96-7719
Synthesis of Cyclic Halooxatelluranes via Dehalogenation of α-Halo Carbonyl Compounds with Tellurides Containing Hydroxy Group on Side Chain

Jian Zhang, Shinichi Saito, Tamiko Takahashi, and Toru Koizumi*

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

Abstract

The synthesis of cyclic halooxatelluranes (3a, 4a-d, 5a) has been achieved via dehalogenation of α-halo carbonyl compounds (2A-F) with tellurides (1a-d) containing hydroxy group on the side chain. Halophilicity of the tellurides was compared with that of selenides and a plausible reaction mechanism is discussed.

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Paper | Regular issue | Vol 45, No. 3, 1997, pp.585-596
Published online:
DOI: 10.3987/COM-96-7722
Regiospecific Hetero Diels-Alder Synthesis of Pyrido[2,3-b]- and Pyrido[3,2-b]carbazole-5,11-diones

Ambroise Poumaroux, Zouhair Bouaziz, Monique Domard, and Houda Fillion*

*Laboratoire de Chimie Organique, Université Claude Bernard, Lyon I, 8 avenue Rockefeller, 69373 Lyon Cedex 08, France

Abstract

Diels-Alder reactions of 2- or 3-bromocarbazolequinones (8) or (9) with azadienes (1) afford regiospecifically pyrido[2,3-b]- or pyrido[3,2-b]carbazole-5,11-diones (3) or (4). Structural assignment of the regioisomers is made by 1H-NMR NOE DIFF experiments. The orientation of the cycloadditions is under control of the bromine atom position on quinones (8) or (9). Calculations by the semiempirical method PM3 of the HOMO and LUMO orbital coefficients of azadienes (1) and quinones (2c), (8) and (9) indicate that the larger ones are situated at C-4 for azadienes (1) and C-3 for the dienophiles.

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15 data found. 1 - 15 listed