Regular Issue

Vol. 48, No. 8, 1998

21 data found. 1 - 21 listed
Communication | Regular issue | Vol 48, No. 8, 1998, pp.1513-1518
Published online:
DOI: 10.3987/COM-98-8197
Stille and Suzuki Cross Coupling Reactions of o-Nitrophenyl Triflates: A Versatile Route to a Variety of Heterocycles

Cedric W. Holzapfel* and Catherine Dwyer

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

Abstract

The cross coupling reactions of selected o-nitrophenyl triflates with arylstannane and arylboron substrates are reported. The resultant 2-nitrobiphenyls provide ready access to a variety of substituted heterocycles.

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Communication | Regular issue | Vol 48, No. 8, 1998, pp.1519-1522
Published online:
DOI: 10.3987/COM-98-8200
Facile Formation of Cyclic Polysulfides by a New Generation Method for Diatomic Sulfur

Kentaro Okuma,* Seiji Kuge, Yuji Koga, Kosei Shioji, Hisanobu Wakita, and Takahisa Machiguchi

*Department of Chemistry, Faculty of Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

Abstract

A new generation of diatomic sulfur (1) has been achieved in a remarkably simple process by treatment of elemental sulfur with sodium hydride in the presence of phase-transfer catalysts. This facile generation of 1 has been trapped with olefins, diene, and triene to give cycloadducts as the form of cyclic sulfides in high yields.

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Communication | Regular issue | Vol 48, No. 8, 1998, pp.1523-1526
Published online:
DOI: 10.3987/COM-98-8238
Stereoselective Synthesis of Hexahydro-1,4-thiazepin-3-one and Dihydro-1,4-thiazin-3-one Derivatives

Michinori Karikomi, Tohru Yamazaki, Yukiko Abematsu, Kiyoshi Masuzawa, and Takashi Toda*

*Department of Applied Chemistry, Faculty of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Japan

Abstract

Diastereomerically pure 4-benzyl-7-substituted 6-hydroxyhexahydro-1,4-thiazepin-3-one and 4-benzyl-1’-hydroxyalkyl-1,4-tetrahydrothiazin-3-one derivatives are obtained by the reaction of a 2,3-epoxy alkylamine derivative with methyl thioglycolate in good yields. trans-Epoxy amine derivatives gave trans-thiazepinone derivatives and anti-thiazepinone derivatives whilst cis-epoxy amines gave cis-thiazepinone and syn-thiazepinone derivatives. Substituent effects on regioselectivity were also examined with the use of several epoxy amine derivatives.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1527-1535
Published online:
DOI: 10.3987/COM-98-8150
Versatile Synthesis of 2-Aryloxyalkyl-oxirane-2-carboxylate: Syntheses of Ethyl 2-[6-(3-Alkoxyphenoxy)hexyl]oxirane-2-carboxylates

Young-Ger Suh,* Kyung-Hoon Min, So-Young Baek, and Jung-Hyeon Chai

*College of Pharmacy, Seoul National University, Shillim-Dong, San 56-1, Kwanak-Gu, Seoul 151-742, Korea

Abstract

A versatile synthetic route to 2-aryloxyalkyl-oxirane-2-carboxylates as potential hydroglycemic agent has been developed via combination of dioxirane epoxidation of inactive olefin and facile aryl alkyl ether formation of the labile epoxy alcohol by Mitsunobu reaction.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1537-1554
Published online:
DOI: 10.3987/COM-98-8174
Synthesis of 7-Methyl Derivatives of 5,10-Dideaza-5,6,7,8-tetrahydrofolic Acid (DDATHF), 5,10-Dideaza-5,6,7,8-tetrahydrohomofolic Acid (HDDATHF), and LY254155

Edward C. Taylor* and Yao Wang

*Department of Chemistry, Princeton University, Princeton, New Jersey 08544, U.S.A.

Abstract

7-Methyl derivatives of DDATHF, homoDDATHF and the thiophene analog of DDATHF (LY254155) were prepared as potential antitumor agents.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1555-1566
Published online:
DOI: 10.3987/COM-98-8179
Synthesis of Novel 5,6,7,8-Tetrahydro-4H-thieno[2,3-b][1,4]diazepine Derivatives

Hidetsura Cho,* Kengo Murakami, Akitaka Fujisawa, Misako Niwa, Hiroyuki Nakanishi, and Itsuo Uchida

*Central Pharmaceutical Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, TAkatsuki-shi, Osaka, 569-1125, Japan

Abstract

Unsubstituted 5,6,7,8-tetrahydro-4H-thieno[2,3-b][1,4]diazepine (1) and 4H-thieno[2,3-b][1,4]diazepine-5,7(6H,8H)-dione (2) were newly synthesized. Benzoylation of 1 regioselectively afforded thienodiazepine (13) substituted with a benzoyl group at position 4. Alternatively, novel synthetic procedures were devised to yield thienodiazepine (22) substituted with an alkyl group or compound (14) with an aralkyl group at position 8. Thus, the ingenious introduction of functional groups at the N-4 or 8 position of a thienodiazepine skeleton was achieved and then a variety of 5,6,7,8-tetrahydro-4H-thieno[2,3-b][1,4]diazepines (5)-(9), and (27), some of which exhibited potent arginine vasopressin antagonistic activity, were obtained using the key intermediates (1), (13), (14), and (22).

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1567-1574
Published online:
DOI: 10.3987/COM-98-8185
Debenzotriazolylation of α-Benzotriazolyl Ketones with Samarium Diiodide

Alan R. Katritzky,* Junquan Wang, and Scott A. Henderson

*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, U.S.A.

Abstract

Removal of the benzotriazoyl moiety of α-benzotriazolyl ketones by samarium diiodide at room temperature to give the corresponding ketones in good yields is described.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1575-1580
Published online:
DOI: 10.3987/COM-98-8187
Synthesis of Imidazonaphthyridines and -quinolines

Spiros Grivas* and Peter Schuisky

*Department of Organic Chemistry, Södertörn University College, Karolinska Institutet, Novum Research Park, SE-141 57 Huddinge, Sweden

Abstract

Four 2-amino-3-methylimidazo[4,5-b][1,x]naphthyridines, x=5-8 (6-9) have been obtained from aromatic aldehydes (11-14) and 2-amino-1-methyl-2-imidazolin-5-one (15) in one step. The N1- and N3-methyl isomers of 2-aminoimidazo[4,5-b]quinoline (5 and 10) were prepared from 2-nitrobenzaldehyde via the isolated E-isomers of imidazolin-5-one (17) and imidazolin-4-one (20).

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1581-1591
Published online:
DOI: 10.3987/COM-98-8190
Novel Complex N-Heterocycles via Intramolecular 1,5-Electrocyclizations: 1,2,3,4,4a,5,5a,10-Octahydropyrido-[4",3":2',3']cyclobuta[1',2':4,5]pyrrolo[2,3-b]pyridines

Harald Walter* and Carsten Sundermann

*Chemical Research Crop Protection, Business Unit Fungicides, Novartis Crop Protection AG, Postfach, CH-4002 Basel, Switzerland

Abstract

The synthesis of 2-amino-3-isopropenylpyridine (5) and 2-amino-5-chloro-3-isopropenylpyridine (6) and their toluenesulfonic acid catalyzed reactions in refluxing toluene with some 1-substituted piperidin-4-ones are described. The toluenesulfonic acid catalyzed reaction of the pyridine derivatives (5) and (6) with 1-benzyl-, 1-benzoyl- and 1-methylpiperidin-4-one lead to novel pyrrolo[2,3-b]pyridines (7-12) in good to excellent yields in diastereoisomeric pure form (Scheme 2, Table 1). An intramolecular 1,5-electrocyclization of the dipolar reactive intermediate (13) as a key step (Scheme 3) is proposed for the formation of the compounds (7-12).

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1593-1597
Published online:
DOI: 10.3987/COM-98-8192
Reaction of 1-Benzylindole-2,3-dicarboxylic Anhydride with 3-Bromo-4-lithiopyridine: Formal Synthesis of Ellipticine

Yasuyoshi Miki,* Yoshitaka Tada, and Ko-ichi Matsushita

*Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1, Kowakae, Higashi-Osaka 577-8502, Japan

Abstract

Reaction of 1-benzylindole-2,3-dicarboxylic anhydride with 3-bromo-4-lithiopyridine gave 2-(3-bromoisonicotinoyl)indole-3-carboxylic acid as the sole product. The indole-3-carboxylic acid could be converted to 6-benzylellipticine quinone in five steps.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1599-1607
Published online:
DOI: 10.3987/COM-98-8213
General Method for Synthesis of Erythrinan and Homoerythrinan Alkaloids (2): Application of Pummerer-Type Reaction to the Synthesis of Homoerythrinan Ring System

Jun Toda, Yoshihiro Niimura, Takehiro Sano,* and Yoshisuke Tsuda

*Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan

Abstract

The sythesis of cyclohomoerythrinan (2a), a potential intermediate to homoerythrinan alkaloids, was achieved by a Pummerer-Type cyclization of the hydroindole sulfoxide (11), which was prepared from the dioxopyrroline (6) in five steps via a [2+2] photocycloaddition reaction followed by an anionic 1,3-shift.

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Paper | Regular issue | Vol 48, No. 8, 1998, pp.1609-1622
Published online:
DOI: 10.3987/COM-98-8217
Synthesis of Pyridazino[4,5-b]carbazoles as Potential Antitumor Agents

Norbert Haider,* Rami Jbara, Forouzandeh Khadami, and Richard Wanko

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 14, A-1090 Vienna, Austria

Abstract

The synthesis of a series of new pyridazino[4,5-b]carbazoles (8, 9, 12-14), representing 3-aza analogs of pyrido[4,3-b]carbazole antitumor agents, is described. The key intermediates, d-fused dichloropyridazines of type 5, were subjected to nucleophilic displacement reactions and/or to reductive dehalogenation.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1623-1630
Published online:
DOI: 10.3987/COM-98-8168
Asymmetric Synthesis of So-called "Dehassiline" Isomer, (S)-1-(2'-Hydroxy-5'-methoxybenzyl)-7-hydroxy-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline

Akiko Watanabe and Jun-ichi Kunitomo*

*Faculty of Pharmaceutical Science, Mukogawa-Women's University, 11-68 Koushien Kyuban-Cho, Nishinomiya, Hyogo 663-8179, Japan

Abstract

A so-called "dehassiline" isomer, (S)-1-(2’-hydroxy-5’-methoxybenzyl)-7-hydroxy-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline (1) was asymmetrically synthesized via the stereoselective reduction with
sodium borohydride at -78 °C of the corresponding 3,4-dihydroisoquinolinium ion possessing a chiral auxiliary. The spectral data for the synthetic compound (1) differed from those reported for natural dehassiline, the structure of which must be reexamined.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1631-1638
Published online:
DOI: 10.3987/COM-98-8172
Short-Step Synthesis of 1,3-Disubstituted Naphtho[2,3-c]furan-4,9-dione and Naphtho[2,3-b]furan-4,9-dione by the Friedel-Crafts Reaction

Junko Koyama,* Izumi Toyokuni, Akari Kino, and Kiyoshi Tagahara

*Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan

Abstract

1,3-Dialkylnaphtho[2,3-c]furan-4,9-diones were obtained by the Friedel-Crafts reaction of phthalic anhydride with 2,5-dialkylfurans. The reaction of phthalic anhydride with 2-acetyl-5-methylfuran, instead of 2,5-dialkylfurans, produced 2-methylnaphtho[2,3-b]furan-4,9-dione. The application of this method to the snthesis of 8-hydroxynaphtho[2,3-b]furan-4,9-dione [isodiodantunezone] is also described.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1639-1642
Published online:
DOI: 10.3987/COM-98-8184
A Degradation Study of Vermisporin and Determination of Its Absolute Configuration

Nobuto Minowa,* Yoshio Kodama, Kenzo Harimaya, and Takashi Mikawa

*Pharmaceutical Research Center, Meji Seika Kaisha Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan

Abstract

The absolute configuration of vermisporin (1) was determined by X-Ray crystallography of the degradation product (2), and the decalin derivatives (3) was efficiently prepared from 1.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1643-1648
Published online:
DOI: 10.3987/COM-98-8186
One-Pot Synthesis of 2-Substituted 3-Trifluoromethyl-3-hydroxy-1,2-benzisothiazole 1,1-Dioxides from N-Substituted Benzenesulfonamides

Masahiko Takahashi,* Kenji Ohtsuki, Tetsuya Taga, and Yasunori Chohnan

*Department of Materials Sciences, Faculty of Engineering, Ibaraki University, 4-12-1 Nakanarusawamachi, Hitachi, Ibaraki 316-8511, Japan

Abstract

N,o-Dilithiation of N-substituted benzenesulfonamides followed by the addition of ethyl trifluoroacetate gave 2-substituted 3-trifluoromethyl-3-hydroxy-1,2-benzisothiazole 1,1-dioxides in one-pot.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1649-1658
Published online:
DOI: 10.3987/COM-98-8189
Novel Synthesis of Polyfunctionalized 1,4,4a,9a-Tetrahydro-1-aza-9-oxafluorenes by Unexpected Cycloaddition of 4-(4-Methoxyphenyl)-1,4-dihydropyridines and p-Benzoquinone

Andreas Hilgeroth,* Krystina Kuna, and Uwe Kuckländer

*Institute of Pharmaceutical Chemistry, Department of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany

Abstract

A surprising acid-catalysed cycloaddition reaction occurs between 3,5-diacetyl-4-(4-methoxyphenyl)-1,4-dihydropyridine (4) and p-benzoquinone in dioxane/HClO4 (5%) yielding novel polyfunctionalized 1,4,4a,9a-tetrahydro-1-aza-9-oxafluorenes (9) as exclusive products. On the other hand the corresponding 4-unsubstituted 1,4-dihydropyridine (1) is oxidized by p-benzoquinone. Novel structures are characterized by standard spectroscopy and, furthermore, confirmed by acetylation. The different reactivity of the 4-substituted and 4-unsubstituted derivatives is dicussed on the basis of semiempirical MNDO calculations and redox potentials.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1659-1662
Published online:
DOI: 10.3987/COM-98-8191
Reaction of Disubstituted Cyanamides with Formamides under High Pressure

Isao Shibuya,* Akihiro Oishi, and Masahiko Yasumoto

*National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305, Japan

Abstract

High pressure-assisted co-cyclization of disubstituted cyanamides with formamide or monosubstituted formamides gave 2-amino- or 2-monosubstituted amino-4,6-bis(disubstituted amino)-1,3,5-triazines in one pot.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1663-1668
Published online:
DOI: 10.3987/COM-98-8198
Reduction of 9-Substituted Acridines with Nickel-Aluminum Alloy

Kichinosuke Kamata,* Yoh-ichi Tominaga, Akiyoshi Tori-i, Thies Thiemann, and Shuntaro Mataka*

*Instituete of Advanced Material Study, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan

Abstract

9-Methyl-, 9-ethyl-, 9-propyl-, 9-isopropyl-, and 9-phenylacridines were treated with nickel-aluminum alloy in hydrochloric acid to give the corresponding 1,2,3,4,5,6,7,8-octahydroacridines and 9,10-dihydroacridines. The yields are dependent upon the C-9 substituent.

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Note | Regular issue | Vol 48, No. 8, 1998, pp.1669-1672
Published online:
DOI: 10.3987/COM-98-8207
Improved Synthesis of Watasenia Preluciferin

Hisae Kakoi and Shoji Inoue*

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

Abstract

On heating a mixture of 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (2) and a large excess of p-hydroxyphenylpyruvic acid (4) at 130-140 °C in dioxane, without any reductive treatment, Watasenia preluciferin (1) was obtained directly in one batch process in 63 % yield.

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Review | Regular issue | Vol 48, No. 8, 1998, pp.1673-1724
Published online:
DOI: 10.3987/REV-98-500
Five Nx-Methyladenines: Their Chemistry, Physicochemical Properties, and Biological Activities

Tozo Fujii* and Taisuke Itaya

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

Abstract

Various mono-N-substituted adenines are represented by the corresponding five possible isomers of Nx-methyladenine, namely, 9-methyladenine (2), 7-methyladenine (3), 3-methyladenine (4), 1-methyladenine (5), and N6-methyladenine (6). The chemistry, physicochemical properties, and biological activities of these Nx-methyladenines are reviewed with 366 reference citations.

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21 data found. 1 - 21 listed