Regular Issue

Vol. 53, No. 10, 2000

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 53, No. 10, 2000, pp.2119-2122
Published online:
DOI: 10.3987/COM-00-8992
New Synthesis of KT5823 Indolocarbazole Aglycone

Guillaume E. Burtin,* Daivd J. Madge,* and David L. Selwood

*The Wolfson Institute for Biomedicinal Reseach, Biological and Medicinal Chemsitry, University College London, Cruciform Building, Gower Street, London, WC1E 6AU, U.K.

Abstract

The indolo[2,3-a]pyrrolo[3,4-c]carbazole aglycone of the selective protein kinase G inhibitor KT5823 has been synthesised in four steps and 36% overall yield from 2,3-dichloro-N-methylmaleimide by utilising an efficient new two step reduction sequence for the key imide to amide transformation.

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Communication | Regular issue | Vol 53, No. 10, 2000, pp.2123-2125
Published online:
DOI: 10.3987/COM-00-8993
Reaction of 3-Ethoxycarbonylindolizine-1,2-dicarboxylic Anhydride with (3-Bromo-4-pyridyl)triisopropoxytitanium: Synthesis of 5,12-Dimethylindolizino[2,1-g]isoquinoline (Ellipticine Analogue)

Yasuyoshi Miki,* Noriko Nakamura, Ryota Yamakawa, Hajime Hibino, Hiroko Hachiken, and Ko-ichi Matsushita

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

Abstract

Reaction of indolizine-1,2-dicarboxylic anhydride with (3-bromo-4-pyridyl)triisopropoxy-titanium gave 2-(3-bromoisonicotinoyl)-3-ethoxycarbonyl--indolizine-1-carboxylic acid as the sole product. The indolizine-1-carboxylic acid could be converted to 5,12-dimethyl-indolizine-[2,1-g]isoquinoline in six steps.

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2127-2142
Published online:
DOI: 10.3987/COM-00-8943
Total Synthesis and Conformational Analysis of Monophenyl Substituted Protoporphyrins. IX

Adriana E. Robinsohn, Marta S. Maier, and Graciela Y. Buldain*

*Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, (1113) Buenos Aires, Argentina

Abstract

The total synthesis of meso-monoaryl protoporphyrins (1) and (2) using a MacDonald type [2+2] condensation is described. In this method a bisformyl dipyrrylmethane is treated with a biscarboxydipyrrylmethane. Attempts to obtain the δ-meso-monoaryl protoporphyrin (7) by the a,c-biladiene method failed as it could not be prepared starting from its tripyrrene precursor. The synthesis of the latter compound is described. Molecular modeling studies allowed us to find the most favorable conformations for compounds (1) and (2). In both porphyrins, the exocyclic phenyl group adopts a noncoplanar disposition relative to the plane of the macrocycle. In porphyrin (2) the macrocycle is nearly planar while nonplanar saddle conformation was obtained for porphyrin (1).

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2143-2149
Published online:
DOI: 10.3987/COM-00-8950
Reaction of 3-Ethoxycarbonylindolizine-1,2-dicarboxylic Anhydride: Synthesis of 2-Acylindolizines and Quinones

Yasuyoshi Miki,* Noriko Nakamura, Ryota Yamakawa, Hiroko Hachiken, and Ko-ichi Matsushita

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

Abstract

Reaction of indolizine-1,2-dicarboxylic anhydride with Grignard reagents gave 2-acylindolizine-1-carboxylic acids, which were converted to 2-acylindolizines. The anhydride reacted with anisole in the presence of titanium chloride(IV) to afford 2-(4-methoxybenzoyl)indolizine-1-carboxylic acid, which was also led to 2-(4-methoxybenzoyl)indolizine. Successive treatment of the 2-acylindolizine-1-carboxylic acids with phosphorus pentachloride and aluminum(III) chloride provided the corresponding quinones.

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2151-2162
Published online:
DOI: 10.3987/COM-00-8957
Synthesis of Phenazine 5,10-Dioxides from Benzofuroxan Catalyzed by Molecular Sieves

Tohru Takabatake, Tomoyuki Miyazawa, Mahiro Kojo, and Minoru Hasegawa*

*College of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan

Abstract

The synthesis of substituted phenazines was carried out. Phenazine 5,10-dioxides (3) were obtained from benzofuroxan (1) with dihydroxybenzene derivatives (2) catalyzed by molecular sieves at room temperature.

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2163-2174
Published online:
DOI: 10.3987/COM-00-8970
Reductive Smiles Rearrangement of 1-[(5-Chloro-2-nitrophenyl)sulfonyl]-1H-pyrrole-2-carbohydrazide to 1-Amino-6-chloro-2-(1H-pyrrol-2-yl)benzimidazole

Romano Silvestri, Augusto Pifferi, Gabriella De Martino, Silvio Massa, Carmela Saturnino and Marino Artico*

*Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Studi Farmaceutici, Università di Roma “La Sapienza”, BOX 36 - ROMA 62, Piazzale Aldo Moro 5, 00185 Roma, Italy

Abstract

Treatment of 1-[(5-chloro-2-nitrophenyl)sulfonyl]-1H-pyrrole-2-carbohydrazide with powdered iron in glacial acetic acid afforded 1-amino-6-chloro-2-(1H-pyrrol-2-yl)benzimidazole as the sole product. This compound was also obtained by iron-acetic acid reduction of 1-(5-chloro-2-nitrophenyl)-1H-pyrrole-2-carbohydrazide. Splitting of the sulfone group occurred only in the presence of the carbohydrazide group. In fact, iron-acetic acid reduction of 5-chloro-2-nitrophenyl 2-ethoxycarbonyl-1H-pyrrol-1-yl sulfone gave the expected 2-amino-5-chlorophenyl 2-ethoxycarbonyl-1H-pyrrol-1-yl sulfone. Treatment of this compound with hydrazine yielded the corresponding carbohydrazide, which failed cyclization when reacted with phosphorus pentoxide. Formation of 7-chloropyrrolo[1,2-b] [1,2,5]benzothiadiazepin-11(10H)-one 5,5-dioxide with loss of hydrazine was observed when the above amino hydrazide was reacted with 2-hydroxypyridine or with glacial acetic acid.

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2175-2181
Published online:
DOI: 10.3987/COM-00-8972
A New Synthesis of Pyrazolo[4,3-e][1,2,4]triazines via Acid Promoted Ring Closure of the Phenylhydrazones of 5-Acyl-1,2,4-triazines

Andrzej Rykowski,* Mariusz Mojzych, and Zbigniew Karczmarzyk

*Institute of Chemistry, University of Podlasie, 08-110 Siedlce, Poland

Abstract

The reaction of various substituted phenylhydrazones of 5-acyl-1,2,4-triazines in the presence of 1.1 equivalent of HCl in boiling ethanol-dioxane mixture has been studied. In all reactions the formation of the corresponding pyrazolo[4,3-e][1,2,4]triazines (3a-r) takes place in good yield. The structures of 3a-r were unequivocally established by spectroscopic methods as well as by X-Ray analysis of selected 5-methyl-3-phenyl-7-(p-tolyl)pyrazolo[4,3-e][1,2,4]triazine (3a).

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2183-2189
Published online:
DOI: 10.3987/COM-00-8979
Catalytic Asymmetric Synthesis and Asymmetric Autocatalysis of Chiral 5,5’-(3,3’-Bipyridyl)dialkanediol

Shigehisa Tanji, Tomohiko Nakao, Itaru Sato, and Kenso Soai*

*Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601 Japan

Abstract

(S,S)-(-)-5,5′-(3,3′-Bipyridyl)dialkanediols (5a, b) with up to 98.6% e.e. was synthesized by the enantioselective addition of dialkylzincs to 3,3′-bipyridine-5,5′-dicarbaldehyde (4) using N,N-dipropylnorephedrine as a chiral catalyst. Chiral diol (5a) was found to work as an asymmetric autocatalyst in the enantioselective addition of diisopropylzinc to aldehyde (4).

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2191-2199
Published online:
DOI: 10.3987/COM-00-9007
Reaction of 3-Iodochromone with Nucleophiles. 2. Reaction with Mercaptoazoles

Yoshiaki Sugita,* Shengzhen Yin, and Ichiro Yokoe*

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

Abstract

3-Iodochromone (1a) easily reacted with mercaptoazoles in the presence of potassium carbonate to give 3-azolylthiochromones in good yields. In the case of 2-mercaptobenzimidazole (2a) as a nucleophile, the benzimidazo[2,1-b]thiazole derivative (4a) was obtained as the major product along with 3-(1H-benzimidazol-2-ylthio)chromone (3a). The ratio of the two products was found to be affected by the electron density on the nitrogen atom in the benzimidazole ring.

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Paper | Regular issue | Vol 53, No. 10, 2000, pp.2201-2220
Published online:
DOI: 10.3987/COM-00-9008
A Concise Preparation of Yuehchukene and Its Analogues

Minoru Ishikura,* Katsuaki Imaizumi, and Nobuya Katagiri

*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan

Abstract

The palladium catalyzed carbonylative cross-coupling reaction of indolylborates (2) with vinyl triflates (3) afforded indol-2-yl ketones (4), which were subsequently converted to hexahydroindeno[2,1-b]indoles (5) with the aid of an acid. This protocol was well adapted for the total synthesis of yuehchukene.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2221-2224
Published online:
DOI: 10.3987/COM-00-8961
A Tetracycloundecane Derivative of Pyrrolidinobenzoxazinone

Makhluf J. Haddadin and Musa Z. Nazer*

*Department of Chemistry, American University of Beirut, Beirut, Lebanon

Abstract

Conversion of 2-nitrobenzaldehyde by DBU to anthranilic acid (AA,II) and the reaction of the latter with tetracyclo[6.3.0.04,11.05,9]undecane-3,6-dione (TCUD,I) to produce a heterocyclic tetracycloundecane derivative of pyrrolidinobenzoxazinone (TCUPB,III) are reported.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2225-2232
Published online:
DOI: 10.3987/COM-00-8973
Prieurianin-Type Tetranortriterpenoids from the Bark of Dysoxylum hainanense

Xiao-Dong Luo, Shao-Hua Wu. Xiao-Sheng Yang, Rong-Wei Teng, Yun-Bao Ma, Da-Gang Wu,* Xiao-Jiang Hao, Yang Lu, Xu-Ying Liu, and Qi-Tai Zheng

*Laboratory of Phytochemistry, Kunming Institute of Botany, The Chinese Academy of Sciences, Kunming, Yunnan 650204, China

Abstract

From the ethanolic extract of the bark of Dysoxylum hainanense Merr., three new seco-tetranortriterpenoids structurally related to prieurianin, dysoxylumins A (1), B (2) and C (3) were isolated. Their structures were elucidated on the basis of 1D and 2D NMR techniques. The structure and stereochemistry of compound 1 were demonstrated by X-Ray crystallography.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2233-2240
Published online:
DOI: 10.3987/COM-00-8983
Novel Rings B,D-Secolimonoids from the Stem Bark of Khaya senegalensis

Samir A. M. Abdelgaleil, Hiroaki Okamura, Tetsuo Iwagawa, Matsumi Doe, and Munehiro Nakatani*

*Department of Chemistry and Bioscience, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan

Abstract

Two new rings B,D-secolimonoids, named khayalactol and 1-O-acetylkhayanolide B, were isolated together with three known rings B,D-secolimonoids, methyl angolensate and its 6-hydroxy and 6-acetoxy derivatives, from the ether extract of the stem bark of a meliaceous plant Khaya senegalensis. The structure of these new compounds was elucidated by spectrospcopic means. The antifeedant property of the isolated compounds is also described.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2241-2246
Published online:
DOI: 10.3987/COM-00-8990
A Synthesis of (±)-Dihydronitraraine

Emmi Päiviö, Mathias Berner, Arto Tolvanen, and Reija Jokela*

*Laboratory of Organic Chemistry, Helsinki University of Technology, P.O. Box 6100, FIN-02015 HUT Espoo, Finland

Abstract

A short synthesis of (±)-dihydronitraraine (1) from an unknown 5,6,7,8-tetrahydroisoquinoline ester (3) is presented. The Fry reaction of tetrahydroisoquinolinium salt (4), followed by cyclization and hydrogenation, gave an alloyohimbane derivative (6), which was reduced to yield dihydronitraraine (1). Complete 1H NMR and 13C NMR data of dihydronitraraine (1) and intermediate (6) are reported.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2247-2252
Published online:
DOI: 10.3987/COM-00-8991
Reaction of N-Acylated Isofebrifugine with Acid

Yasuo Takeuchi,* Kumiko Azuma, Hitoshi Abe, and Takashi Harayama

*Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

The reaction of N-acylated isofebrifugine with hydrochloric acid is discussed. Although the corresponding deprotected compound was not isolated, three new heterocyclic compounds were obtained. Based on these findings, new furan and pyrrole derivatives were prepared.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2253-2259
Published online:
DOI: 10.3987/COM-00-8998
First Total Syntheses of (+)-Polyoxin B and (+)-Polyoxin D

Kimio Uchida, Keisuke Kato, Kentaro Yamaguchi, and Hiroyuki Akita*

*School of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

First total syntheses of the peptidyl nucleoside antibiotics, polyoxins B (1) and D (2), are achieved based on the coupling reactions of the N-protected L-carbamoyl-polyoxamic acid derivative (6) with polyoxin C (8), 6 with polyoxin C acid (9), respectively.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2261-2274
Published online:
DOI: 10.3987/COM-00-8999
Formation of Isoquinoline Derivatives by the Irradiation of N-Acetyl-α-dehydrophenylalanine Ethyl Ester and Its Derivatives

Hideki Hoshina, Hitoshi Tsuru, Kanji Kubo, Tetsutaro Igarashi, and Tadamitsu Sakurai*

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

Abstract

The irradiation of a nitrogen-purged acetonitrile solution of the title compounds (1) with Pyrex filtered light was found to give isoquinoline derivatives (2) via the excited state (Z)-isomers, whereas in methanol 1-azetine derivative was also detected along with 2 but side reactions occurred appreciably on prolonged irradiation. An examination of substituent effects on the reactivities of the excited state (Z)-isomers shows that the efficiency for formation of 2 undergoes great steric and electronic effects of the substituent introduced into the benzene ring of 1, though the bulkiness of the alkoxycarbonyl group in 1 affected this efficiency to only a slight extent. On the other hand, in the presence of benzophenone as a triplet sensitizer, the starting (Z)-isomer underwent an exclusive isomerization into the corresponding (E)-isomer without yielding any isoquinoline derivative, being consistent with the occurrence of the photocyclization reaction from the excited singlet state (Z)-isomer.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2275-2278
Published online:
DOI: 10.3987/COM-00-9003
Solvent-free Synthesis of Thio-alkylxanthines from Alkylxanthines Using Microwave Irradiation

Rodrigo Rico-Gómez,* Francisco Nájera, Juan Manuel López-Romero, and Pedro Cañada-Rudner

*Departamento de Química Orgánica, Universidad de Malága, E-29071 Malága, Spain

Abstract

An expeditious, solvent-free procedure for the conversion of the xanthine bases theophylline, 8-methyltheophylline, caffeine, and theobromine to the corresponding 6-thio and 2,6-dithio derivatives using Lawesson’s reagent under microwave irradiation is proposed.

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Note | Regular issue | Vol 53, No. 10, 2000, pp.2279-2283
Published online:
DOI: 10.3987/COM-00-9010
Royleinine, a New Norditerpenoid Alkaloid from Delphinium roylei

Ayhan Ulubelen,* Ali H. Meriçli, Filiz Meriçli, Ufuk Kolak, Muhammed Arfan, Manzoor Ahmad, and Habib Ahmad

*Faculty of Pharmacy, University of Istanbul, 34452 Istanbul, Turkey

Abstract

A new norditerpenoid alkaloid, royleinine (1) has been isolated from the aerial parts of Delphinium roylei Munz, along with three more norditerpenoid alkaloids, isotalitazidine, condelphine and senbusine-C. The structure of 1 has been established on the basis of its spectroscopic data (IR, HRMS, 1H, 13C, 1H - 1H and 1H - 13C COSY and NOESY spectra).

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Review | Regular issue | Vol 53, No. 10, 2000, pp.2285-2336
Published online:
DOI: 10.3987/REV-00-536
Recent Advances in the Synthesis of Heterocycles from Oximes

Edgars Abele and Edmunds Lukevics*

*Latvian Institute of Organic Synthesis, 21 Aizkraukles Street, Riga, LV-1006, Latvia

Abstract

Modern methodologies of preparation of three-, five-, six- and seven-membered heterocyclic compounds from oximes and their derivatives have been reviewed. Syntheses of bicyclic and tricyclic ring systems from oximes are included.

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20 data found. 1 - 20 listed