Regular Issue

Vol. 55, No. 5, 2001

18 data found. 1 - 18 listed
Communication | Regular issue | Vol 55, No. 5, 2001, pp. 823 - 826
Published online:
DOI: 10.3987/COM-01-9159
Effect of Copper(II) Triflate on Intramolecular Diels-Alder Reaction of Oxazole-Olefins

Masashi Ohba* and Rie Izuta

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


Intramolecular Diels-Alder reaction of the oxazole-olefins (8a) and (11a) was effectively promoted by addition of a catalytic amount of copper(II) triflate to afford the cyclopenta[c]pyridines (9a) and (12a), respectively.

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 827 - 834
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DOI: 10.3987/COM-01-9164
Mesomeric Betainium Salts. Synthesis, X-Ray Analysis, and ESIMS Studies of Tripolar Pyrimidin-4-olates and Pyrimidin-4-aminides

Andreas Schmidt* and Martin Nieger

*Institut für Organische Chemie, Technische Universität Clausthal, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany


Reaction of tetrachloropyrimidine (1) with pyridine in acetone in the presence of sodium iodide yielded the pyrimidin-4-olate (3). Applying analogous reaction conditions to 4-amino substituted 2,5,6-trichloropyrimidine (4a,b) resulted in the formation of bispyridinium salts (5a,b) which yield aminides (6a,b) on deprotonation. As evidenced by means of UV spectroscopy and electron spray MS spectrometry, the title compounds (3) and (6a,b) form π-sandwich complexes in solution.

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 835 - 840
Published online:
DOI: 10.3987/COM-01-9172
Convenient Syntheses of Fragment B and Linear Main Skeleton [Fragment A-B-C’] Derivatives of an Antibiotic, GE 2270 A

Taishi Suzuki, Atsushi Nagasaki, Kazuo Okumura, and Chung-gi Shin*

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


Convenient synthesis of the protected linear precursor [Fragment A-B-C’] of a macrocyclic antibiotic, GE 2270 A, was achieved by coupling of a 2,3,6-tristhiazolyl-substituted pyridine skeleton [Fragment A-C’] with a thiazoloylthiazole segment [Fragment B]. The Fragment B was synthesized from an appropriate thioamide and β-bromo-α-oxoalkanoate, the latter of which was first derived by consecutive β-bromination and hydrolytic removal of the α-(N-Boc)amino group of an α-dehydroamino acid ester.

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 841 - 846
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DOI: 10.3987/COM-01-9178
Inhibitors of Nitric Oxide Production and New Sesquiterpenes, 4-epi-Curcumenol, Neocurcumenol, Gajutsulactones A and B, and Zedoarolides A and B from Zedoariae Rhizoma

Hisashi Matsuda, Toshio Morikawa, Iwao Toguchida, Kiyofumi Ninomiya, and Masayuki Yoshikawa*

*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan


Six new guaiane- or secoguaiane-type sesquiterpenes, 4-epi-curcumenol, neocurcumenol, gajutsulactones A and B, and zedoarolides A and B, were isolated from aqueous acetone extract of Zedoariae Rhizoma (Zingiberaceae), together with 34 sesquiterpenes and two diarylheptanoids. The stereostructures of new sesquiterpenes were elucidated on the basis of chemical and physicochemical evidence, which included nuclear Overhauser effect (NOE) and circular dichroic (CD) spectroscopic analyses. Gajutsulactones A and B, and 14 sesquiterpenes, and two diarylheptanoids were found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated mouse peritoneal macrophages

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 847 - 850
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DOI: 10.3987/COM-01-9179
Thermodynamically Controlled Deracemization of 2-Alkylcycloalkanones Utilizing Host-Guest Inclusion Complexation

Hiroto Kaku, Shinobu Ozako, Shiho Kawamura, Shinobu Takatsu, Masayuki Ishii, and Tetsuto Tsunoda*

*Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamabouji, Yamashiro-machi, Tokushima, 770-8514, Japan


Based on host-guest inclusion complexation in the solid state, α-substituted cycloalkanones were deracemized using optically active host compound, TADDOL (2a) in alkaline conditions.

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 851 - 854
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DOI: 10.3987/COM-01-9185
The First Synthesis and Characterization of Bisbenzotrithiole Containing Two Benzotrithioles Linked by an Alkanedioxy Spacer

Ryu Sato,* Yoshiyuki Utsumi, Shiduko Nakajo, Satoshi Ogawa, and Yasushi Kawai

*Department of Applied Chemistry, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan


The first synthesis and electrochemical characterization of 7,7’-diethyl-4,4’-ethylenedioxybis(benzo[1,2-d][1,2,3]trithiole) (A) containing two benzotrithiole rings linked by an ethylenedioxy group are described.

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Communication | Regular issue | Vol 55, No. 5, 2001, pp. 855 - 859
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DOI: 10.3987/COM-01-9192
Synthesis of Trisubstituted 4-Oxepanones by the Lewis Acid-promoted Three-Component Ring-Expansion Reaction of Cyclopropapyranones, Silyl Enolates and Glyoxylates

Yoshiaki Sugita,* Chikasa Kimura, and Ichiro Yokoe

*Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan


In the presence of SnCl4, cyclopropapyranones easily reacted with silyl enolates and ethyl glyoxylate to give the trisubstituted 4-oxepanones in good yields.

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 861 - 871
Published online:
DOI: 10.3987/COM-00-9080
Simple Synthesis of (±)-Epibatidine

Balaram Roy, Hidenori Watanabe, and Takeshi Kitahara*

*Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan


Concise synthesis of racemic epibatidine (1), a non-opioid analgesic alkaloid, was accomplished starting from 6-chloropyridyl-3-carbaldehyde (6) via Robinson annulation for the construction of the skeleton, by introduction of amino group through Curtius rearrangement and finally by cyclization.

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 873 - 880
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DOI: 10.3987/COM-00-9146
Synthesis of Vinca Alkaloids and Related Compounds 95. Attempted Build-up of the Aspidospermidine Skelton by [4+2] Cycloaddition. Some Unexpected Reactions, and Formation of a New Ring System

István Vágó, György Kalaus,* István Greiner, Mária Kajtár-Peredy, János Brlik, Lajos Szabó, and Csaba Szántay*

*Department for Organic Chemistry, Technical University of Budapset, Gellért tér 4, P.O. Box 91, H-1521 Budapset, Hungary


The reaction of the 2-vinylindole derivative (10) with methyl 4-formylbutanoate (11a) gave a pyrido[1,2-a]indole (13), instead of the expected seco-aspidospermidine (12). Similarly, this cycloaddition reaction failed with the vinyl-enamide (19), the products were two 5H-pyrido[1’,2’:1,8]azocino[5,4-b]-indole derivatives, (20 and 21).

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 881 - 888
Published online:
DOI: 10.3987/COM-01-9169
Reaction of 3-Iodochromone with Nucleophiles 3. Formation of 2-Aminomethylene-3(2H)-benzofuranones by the Reaction with Secondary Amines

Yoshiaki Sugita,* Takako Iwaki, Misaki Okamoto, and Ichiro Yokoe*

*Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan


3-Iodochromone (4a) easily reacted with secondary amines in the presence of potassium carbonate to give 2-aminomethylene-3(2H)-benzofuranones in good yields. Under similar conditions without potassium carbonate, 4a was reacted with piperidine to give the enamino ketone (5) as the major product.

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 889 - 903
Published online:
DOI: 10.3987/COM-01-9171
Synthesis of cis- or trans-2,4-Disubstituted Tetrahydrofurans Bearing Amino and Imidazole Groups by Efficient Use of the Modified or Standard Mitsunobu Cyclization: Synthetic Studies toward Novel Histamine H3-Ligands

Lisa Araki, Shinya Harusawa, Ikuno Ijichi, Hirofumi Ohishi, and Takushi Kurihara*

*Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan


4(5)-[(2R,4S) or (2S,4S)-4-Aminotetrahydrofuran-2-yl]imidazole [(-)-1a or (-)-1b] and its enantiomers [(+)-2a and (+)-2b] were synthesized by efficient use of the modified or standard Mitsunobu cyclization.

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 905 - 924
Published online:
DOI: 10.3987/COM-01-9173
2,4,6-Tris(azol-1-yl)-1,3,5-triazines: A New Class of Multidentate Ligands

Viktor Milata, Rosa María Claramunt,* Pilar Cabildo, María Dolores Santa María, Pilar Cornago, Lourdes Infantes, Felix H. Cano, and Jose Elguero

*Departamento de Química Orgánica y Biologiá, Faclutade de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain


The synthesis of thirteen tris(azol-1-yl)-s-triazines (azole = pyrazoles, imidazoles, 1,2,4-triazole and benzimidazoles) is described. Particularly interesting are the compounds derived from C-adamantylazoles (4-adamantylpyrazole, 2-adamantylimidazole and 2-adamantylbenzimidazole) because of their high lipophilicity. The crystal and molecular structures of 2,4,6-tris(2-phenylimidazol-1-yl)-1,3,5-triazine (6c) and 2,4,6-tris(2-phenylbenzimidazol-1-yl)-1,3,5-triazine (8c) have been determined by X-Ray analysis. The molecular structure can be described as a propeller taking into account the twists existing between the central ring and the substituents. The crystal structure of both compounds show a distorted hexagonal packing of chains. All trisazolyltriazines have been fully characterized by 1H-, 13C- and 15N-NMR spectroscopy. The 13C and 15N chemical shifts in CDCl3 and trifluoroacetic acid have been used to discuss the conformation and the site of protonation.

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Paper | Regular issue | Vol 55, No. 5, 2001, pp. 925 - 940
Published online:
DOI: 10.3987/COM-01-9181
A Straightforward Synthesis of Pyridopyrazino[2,3-b]indoles and Indolo[2,3-b]quinoxaline

France-Aimée Alphonse, Sylvain Routier, Gérard Coudert, and Jean-Yves Mérour*

*Institut de Chimie Organique et Analytique, UMR CNRS 6005, BP 6759, Université d'Orléans, Rue de Chartres, 45067 Orléans Cédex 2, France


1,2-Diamines (ethylenediamine, o-phenylenediamine, 2,3-diaminopyridine, 3,4-diaminopyridine) were reacted with 1-acetyl-2-bromo-3-indolinone to afford 5H-pyrazino[2,3-b]indoles, indolo[2,3-b]quinoxaline and pyridopyrazino[2,3-b]indole in good yields. Alkylation of the indolic nitrogen atom of these indolic derivatives with 2-chloroethylmorpholine, 2-chloroethyldimethylamine and allyl bromide was carried out in order to obtain the corresponding N-alkylated derivatives.

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Note | Regular issue | Vol 55, No. 5, 2001, pp. 941 - 949
Published online:
DOI: 10.3987/COM-01-9160
Diastereoselective Synthesis of 1-Aza-spiro[5.5]undecane Skeleton

Marc David, Hamid Dhimane, Corinne Vanucci-Bacqué, and Gérard Lhommet*

*Université P. et M. Curie, UMR 7611, Laboratoire de Chimie des Hétérocycles, case courrier 43, 4 Place Jussieu, F-75252 Paris Cedex 05, France


The synthesis of various bicyclic enamines (5), bearing a side chain with a multiple C-C bond or a furan ring, was performed from racemic pipecolic acid through sulfone (1c). Cyclization of these derivatives (5), via the corresponding in situ generated N-acyliminium ions, was studied in various acidic conditions to afford, in some cases, spiro intermediates (2) which possess the backbone of the histrionicotoxin family of alkaloids.

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Note | Regular issue | Vol 55, No. 5, 2001, pp. 951 - 960
Published online:
DOI: 10.3987/COM-01-9162
A General Large Scale Synthesis of 2-Alkyl-7-methoxyindoles

Bang-Chi Chen,* John Hynes, Jr., Chennagiri R. Pandit, Rulin Zhao, Amanda P. Skoumbourdis, Hong Wu, Joseph E. Sundeen, and Katerina Leftheris*

*Discovery Chemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543-4000, U.S.A.


A general method has been developed for the large scale synthesis of 2-alkyl-7-methoxyindoles and analogs. This method involves an efficient preparation of the key intermediates, 1-(2-nitroaryl)-2-nitroalkanols and 1-(2-nitroaryl)-2-nitroalkenes, and affords 2-alkyl-7-methoxyindoles and analogs in 3 steps with good overall yields.

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Note | Regular issue | Vol 55, No. 5, 2001, pp. 961 - 966
Published online:
DOI: 10.3987/COM-01-9175
Mechanistic Studies on Racemization of Chiral 2-Arylthiazolidinons

Tatsuya Kato* and Tomokazu Ozaki

*Fiji Gotemba Research Laboratories, Chugai Pharmaceutical Company, Ltd., 135, 1-Chome Komakado, Gotemba City, shizuoka 412-8513, Japan


Mechanistic studies on racemization of chiral 3-[(2S)-2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4-oxo-1,3-thiazolidin-3-yl]propanoic acid is described. This racemization is triggered by deprotonation of phenolic hydroxyl group. We propose that the racemization proceeds via a novel mechanism involving ring opening-closure equilibrium of the thiazolidinone ring.

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Note | Regular issue | Vol 55, No. 5, 2001, pp. 967 - 972
Published online:
DOI: 10.3987/COM-01-9182
An Efficient Synthesis of 4,6-Dimethoxyaurones

Chantal Beney, Anne-Marie Mariotte, and Ahcène Boumendjel*

*Laboratoire de Pharmacognosie, Département de Pharamcognosie Moleculaire, UMR-CNRS 5063, UFR de Pharmacie de Grenoble, 38706 La Tronche, France


4,6-Dimethoxybenzofuran-3(2H)-one was synthesized in two steps Starting from phloroglucinol and used as a useful starting block for the synthesis of aurones by condensation with benzaldehyde derivatives.

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Note | Regular issue | Vol 55, No. 5, 2001, pp. 973 - 980
Published online:
DOI: 10.3987/COM-01-9186
Synthesis of 4-(1-Dialkylaminoalkyl)pyrrolo[1,2-a]quinoxalines

Kazuhiro Kobayashi,* Takashi Matsumoto, Susumu Irisawa, Keiichi Yoneda, Osamu Morikawa, and Hisatoshi Konishi

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


The reaction of 1-(2-isocyanophenyl)pyrroles (1), which were readily prepared from commercially available or known 1-(2-aminophenyl)pyrroles by formylation in refluxing ethyl formate followed by dehydration with POCl3/Et3N in THF, with Eschenmoser's salt (2) proceeded smoothly at room temperature to give the dimethyl(pyrrolo[1,2-a]quinoxalin-4-ylmethyl)ammonium iodides (3) in good yields (74—75%). 1-(2-isocyanophenyl)pyrrole (1a) was also found to react with a range of iminium salts (5) and (7), derived from secondary amines and aldehydes in the presence of Me3SiCl/NaI/Et3N, to give 4-(1-dialkylaminoalkyl)pyrrolo[1,2-a]quinoxaline derivatives (6), (8), and (9) in isolated yields ranging from 47 to 99%.

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