HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 57, No. 12, 2002
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■ Synthesis of New Thiopyrylocyanines Incorporated Thiopyrano[2,3-b]indole Ring as the Main Constituent
Yoshinori Tominaga,* Yasuhiro Shigemitsu, and Shun-ichi Hirayama
*Nagasaki University, Center of Instrumental Analysis, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan
Abstract
The Diels-Alder product, dimethyl 5-methyl-4a-methyl-1-methylthiothiopyrano[4,3-b]indole-3,4-dicarboxylate (2b), which was obtained by the reaction of methyl 1,2-dimethylindole-3-dithiocarboxylate (1b) with DMAD (dimethyl acetylenedicarboxylate), was easily converted to a 1,5-dimethyl-2,3-bis(methoxycarbonyl)indolo[2,3-b]thiopyrylium perchlorate (5) as the key intermediate for the thiopyrylocyanine and merocyanine dyes. Compounds (5 and 6) were allowed to react with aromatic aldehydes and some electrophilic reagents to yield cyanine and merocyanine dyes (8a-c, 10-12) in good yields.
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■ Synthesis, Tautomerism and Calculations of Mesomeric Betaines of Guanine
Andreas Schmidt* and Nikoloz Kobakhidze
*Institut für Organische Chemie, Technische Universität Clausthal, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
Abstract
Reaction of purine-N-oxide (4) with 4-(dimethylamino)pyridine and acetyl chloride, followed by the treatment with hydrochloric acid gave the purinepyridinium salt (6) which was deprotonated to the mesomeric betaine (7). Depending on the reaction conditions, 4-methylpyridine and pyridine, respectively, converted the nucleoside (8) into the pyridinium salts (9) and (10), or into the mesomeric betaines (11) and (12). According to calculations, the conjugated tautomers (A-D) of betaine (7) are more stable than the cross-conjugated tautomer (7E).
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■ Synthesis and Characterisation of Extended π-Bonding Systems in Cycloimmonium Ylides Derived from the 4,4’-Bipyridine
Ludovic Depature* and Gheorghe Surpateanu
*Laboratoire de Synthèse Organique et Environnement, Maison de la Recherche Environnement Industriel de Dunkerque, Université du Littoral, 145 rue Maurice Schumann, 59140 Dunkerque, France
Abstract
Disubstituted cycloimmonium ylides derived from the 4,4’-bipyridine with one, two or four ylidic systems in their molecular structure are described as stable compounds. Synthesis of some bridged 1,1’-disubstituted 4,4’-bipyridinium dimethylides in which 1,4- or 1,3-phenylene spacers may be used, provide some new macromolecular cycloimmonium ylides with spatially extended π-bonding system. These compounds were obtained by the chemical conversion of 4,4’-bipyridinium salts as viologens or bis-viologens, with acylating or carbamoylating agents, in basic media. The characterisation of all compounds has been mainly performed by 1H and 13C NMR spectroscopy.
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■ Heterocyclization of vic-Substituted Hydroxamic Acid Salts of Acetylenylpyrazoles: a New Procedure for the Preparation of Pyrazolo[3,4-c]pyridin-7-ones
Sergei F. Vasilevsky,* Elena V. Mshvidobadze, and José Elguero*
*Instituto de Química Médica, C. S. I. C., Calle Juan de Cierva, 3, 28006 Madrid, Spain
Abstract
Procedures for the preparation of 5-substituted pyrazolo[3,4-c]pyridin-7-ones and 5-substituted 6-hydroxypyrazolo[3,4-c]pyridin-7-ones have been developed based on heterocyclization of vic-acetylenylpyrazolylhydroxamic acids under the influence of copper(I) salts in dimethylformamide or with organic bases in butanol or methanol.
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■ Palladium-catalyzed Synthesis of 2,2-Dimethyl-3-pyrrolines from α-Amino Allene and Aryl Iodides
Takanori Shibata,* Sho Kadowaki, and Kentaro Takagi
*Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan
Abstract
Palladium-catalyzed cyclization of dimethyl-substituted allene possessing amino functionality with aryl iodides efficiently proceeded in the presence of diisopropylethylamine to give 2,2-dimethyl-3-aryl-3-pyrrolines. Under an atmospheric pressure of carbon monoxide, 3-aroyl-3-pyrrolines are provided in good yield.
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■ Synthesis of Novel Tetra- and Pentacyclic Fused Benzimidazole Derivatives
Jae Sang Yi and Kyongtae Kim*
*School of Chemistry and Molecular Engineering, Seoul National University, Shillim-Dong, San 56-1, Seoul 151-742 , Korea
Abstract
Treatment of 7,12-dihydro[5,6][1,3]thiazepino[3,2-a]benzimidazole 6,6-dioxide (1) with NaH (1.2 equiv.) for 30 min in THF at room temperature under nitrogen atmosphere, followed by addition of alkyl propiolate (4 equiv.) gave tetracyclic benzimidazole derivatives (7). Subsequent reactions of 7 with Na in p-xylene at reflux, followed by addition of HOAc at room temperature gave pentacyclic benzimidazole derivative (8) in good to excellent yields.
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■ Synthesis of Optically Active 2-Acetoxy-3-alkylidene-α-lycoranes for a Synthetic Approach toward (+)-Lycorine by Radical Reaction
Miyuki Ishizaki,* Yuichiro Kai, and Osamu Hoshino*
*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 12, Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan
Abstract
A radical-mediated synthesis of optically active 2α- and 2β-trimethylsilylmethyene-α-lycoranes (3,4), which are key intermediates for synthesis of (+)-lycorine (2), is described. Thus, both B and C rings in lycorine (2) were constructed by 6-exo mode radical cyclization. The former ring formation was performed in diastereoselective manner by radical cyclization via α-acylamino radical of (4S,5R)-4-acetoxy-N-(2-methoxy-, 2-benzyloxy-, and 2-tert-butoxy-carbonylethenyl-4,5-methylenedioxybenzyl)- or (4S,5R)-N-(2-tert-butoxycarbonylethenyl-4,5-methylenedioxybenzyl)-4-triethylsilyloxy-5-phenyl-selenyl-2-pyrrolidinones (10-12 or 19). The latter ring formation was accomplished by the reaction of (1S,10R,10aR,2’S)- and (1S,10R,10aR,2’R)-10-(2’-acetoxy-4’-trimethylsilyl-3’-butynyl)-1-imidazolylthiocarbonyloxy-7,8-methylenedioxy-1,2,3,5,10,10a-hexahydrobenz[f]indolizidines (28).
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■ A Convenient Synthesis of 3-Benzoylisoazoles by 1,3-Dipolar Cycloaddition
Hiroyuki Kai,* Minoru Tomida, Toru Nakai, and Akira Takase
*Discovery research Laboratories, Shionogi & Co. Ltd.,Gotanda, Koka-cho, Koka-gun, Shiga 520-3423, Japan
Abstract
A convenient, efficient method for the preparation of 3-benzoylisoxazoles is described. Nitrile oxides generated in situ from phenylglyoxylohydroxamyl chlorides and NaHCO3 in isopropyl alcohol smoothly react with dipolarophiles at room temperature to provide the cycloadducts.
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■ Isomerization and Application of Aroylnorbornanecarboxylic Acids for Stereoselective Preparation of Heterocycles
Ferenc Miklós, Pál Sohár,* Antal Csámpai, Reijo Sillanpää, Mária Péter, and Géza Stájer*
*Institute of Pharmaceutical Chemistry, University of Szeged, PO Box 121, H-6720 Szeged, Eötvös u. 6, Hungary
Abstract
When boiled in acidic or basic solution, diendo-3-aroylbicyclo[2.2.1]heptane-2-carboxylic acids (1 and 1a) isomerize to exo-3-aroylbicyclo[2.2.1]heptane-endo-2-carboxylic acids (2 and 2a). Similar endo→exo and even exo→endo isomerization of the aroyl group occurred when the Diels-Alder product containing a mixture of 3-exo-p-toluoylbicyclo[2.2.1]hept-5-ene-2-endo-carboxylic acid (4) and 3-endo-p-toluoylbicyclo[2.2.1]hept-5-ene-2-exo-carboxylic acid (5) was reacted with bifunctional reagents: o-aminothiophenol, 3-amino-1-propanol, 1,4-diaminobutane or diexo-3-hydroxymethylbicyclo[2.2.1]heptane-2-amine. All the reactions yielded mixtures of norbornene diendo- and diexo-fused heterocycles (6) and (7, 8 and 10, 9 and 11, or 12 and 13), which were separated and whose structures were established by means of IR, 1H- and 13C-NMR spectroscopy, with DIFFNOE, 2D-COSY, DEPT, HMQC and HMBC measure-ments.
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■ An Efficient Synthesis of N-Alkyl-4-substituted-3H-pyridine-2,6-dione. Synthesis of Isoguvacine and MDL-11,939
Meng-Yang Chang, Shui-Tein Chen,* and Nein-Chen Chang
*Institute of Biological Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, NanKang, Taipei, 11529, Taiwan, R.O.C.
Abstract
An efficient route towards the synthesis of N-alkyl-4-substituted 3H-pyridine-2,6-dione using various N-alkyl-α-sulfonylacetamides and two α,β-unsaturated esters as starting materials is described. Isoguvacine and MDL-11,939 with have potential biological activities were synthesized via this strategy.
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■ Synthesis of 7-Aminopyrazolo[3,4-c]pyridine as a Probe for the Preparation of compounds of Pharmacological Interest
Vassilios N. Kourafalos, Panagiotis Marakos, Nicole Pouli,* Aris Terzis, and Leroy B. Townsend*
*Division of Pharmaceuical Chemistry, Department of Pharmacy, University of Athens, Panepistimiopolis-Zografou, Athens GR-15771, Greece
Abstract
A synthetic route towards the preparation of 7-aminopyrazolo[3,4-c]pyridine is developed, starting from the readily accessible 2-amino-4-methyl-3-nitropyridine. The unexpected formation of 7-methylimidazolo[4,5-b]pyridin-2-one during the reaction sequence is also described.
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■ Chemistry of Renieramycins. Part 2. Partial Reduction and Nucleophilic Substitution of Hexahydro-1,5-imino-4-oxo-3-benzazocine-7,10-dione: Promising Method to Construct Renieramycin J from Renieramycin G via Renieramycin E
Yu-ichi Koizumi, Akinori Kubo, Khanit Suwanborirux, and Naoki Saito*
*Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
Abstract
The conversion of 1,2,3,4,5,6,7,10-octahydro-9-methoxy-3,8,11- trimethyl-1,5-imino-3-benzazocine-4,7,10-trione (8) to the corresponding alkylated compound at C-21 position (11) as an ABC ring model of renieramycin J (1j) is described. This is a promising method for converting renieramycin G (1g) into 1j via renieramycin E (1e).
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■ A New Access to the Cleavage of the N-19 Bond of Norditerpenoid Alkaloids and Their Derivatives by Formation of Oxaziridines
Qiao-Hong Chen, Liang Xu, and Feng-Peng Wang*
*Department of Chemistry of Medicinal Natural Products, West China College of Pharmacy, Sichuan University, No. 17, Duan 3, Remin Nan Road, Chengdu 610041, China
Abstract
A new N,19-seco-norditerpenoid alkaloidal compound (5) possessing an oxaziridine group from yunaconitine (1) was furnished by using a new method in five steps involving acetylation, imination, quaternization, formation of N,O-mixed ketal, and oxidation in 50% overall yields.
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■ Tautomerism and X-ray Structure of Dihydro-5H-1,3,4-benzotriazepin-5-ones
Jalal A. Zahra, Bassam A. Abu Thaher, Mustafa M. El-Abadelah,* and Martti Klinga
*Chemistry Department, Faculty of Science, University of Jordan, Amman 11942, Jordan
Abstract
Single X-Ray crystal structure determination of dihydro-5H-1,3,4-benzotriazepin-5-one (2b) revealed that the mobile hydrogen is σ–bonded to N1, while the double bond is situated between C2-N3. In this prevailing 1,4-dihydro tautomer (2A) ( preferred over the alternate 3,4-dihydro form 2B ), both azomethine C2-N3 atoms are folded away, out of the plane comprising the rest bicyclic skeletal atoms, in a “boat”-like manner. Cyclocondensation of the C-acetylcarbohydrazonamides (1a, b) with acetic anhydride is reinvestigated and found to deliver the respective 2a, b, but not the isomeric 4-(3H)quinazolinones (3a, b) as was previously reported.
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■ Preparation and Structure of 3,4,8,9-Tetrachloro-2,5,7,10-tetrahydro[1,6]dithiecine
David L. Eaton, John P. Selegue,* John Anthony, and Brian O. Patrick
*Department of Chemistry, University of Kentucky, University of Kentucky, Lexington, KY 40506-0055, U.S.A.
Abstract
The reaction of Z-1,4-dibromo-2,3-dichlorobut-2-ene (1) with sodium sulfide leads to 3,4,8,9-tetrachloro-2,5,7,10-tetrahydro[1,6]dithiecine (2) as the principal product, rather than the anticipated 3,4-dichloro-2,5-dihydrothiophene (3). Compound (2) was characterized spectroscopically and its structure determined by X-Ray crystallography.
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■ Synthesis of 4-(1,4-Diaryl-2H-cyclopent[d]pyridazin-2-yl)benzenesulfonamides
Mark Blankenbuehler* and Sean Parkin
*Department of Physical Sciences, Morehead State University, Morehead, Kentucky, 40351, U.S.A.
Abstract
The condensation of cyclopentadienyl-derived γ-diketones and arylhydrazines was utilized to synthesize 4-(1,4-diphenyl-2H-cyclopent[d]pyridazin-2-yl)benzenesulfonamide and 4-(1,4-di-(4-methylphenyl)-2H-cyclopent[d]pyridazin-2-yl)benzenesulfonamide in better than 80% yield. The crystal structures of the precursor hydroxyfulvene, {(5Z)-5-[hydroxy(4-methyl-phenyl)methylene]cyclopenta-1,3-dien-1-yl}(4-methylphenyl)methanone, and the derived pyridazine 4-(1,4-diphenyl-2H-cyclopent[d]pyridazin-2-yl)-benzene-sulfonamide, were also obtained.
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■ Reactivities of 2-Aminomethylimidazole: an Approach for the Synthesis of Imidazo[1,5-a]imidazole
Sujin Park and Yonghan Kang*
*Department of Chemistry, College of Science, Hanyang University, 1271 Sa-1-dong, Ansan-si, Kyunggi-do 425-791, Korea
Abstract
A synthesis of 5-oxo-1H-5,6-dihydroimidazo[1,5-a]imidazole which has 5,5-fused heteroaromatic ring system is described.
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■ Phenanthroindolizidine Alkaloids and Their Cytotoxicity from the Leaves of Ficus septica
Pei-Lin Wu,* K. V. Rao, Chia-Hao Su, Cheng-Sheng Kuoh, and Tian-Shung Wu*
*Department of Chemistry, Natioanl Cheng Kung University, Tainan, 70101, Taiwan, R.O.C.
Abstract
Phenanthroindolizidine N-Oxide, ficuseptine-A (1), together with eighteen known compounds was isolated from the leaves of Ficus septica. The structures of these compounds were elucidated by spectroscopic analysis. Among them, phenanthroindolizidines, ficuseptine (1), (+)-tylophorine (4) and a mixture of (+)-tylocrebrine (5) and (+)-isotylocrebrine (6), exhibited strong cytotoxic activity against two human cancer cell lines, NUGC and HONE-1.
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■ A New Tricyclic Iridoid Glucoside from the Thai Medicinal Plant, Rothmannia wittii
Tripetch Kanchanapoom, Sapsuang Klai-on, Ryoji Kasai, Hideaki Otsuka, and Kazuo Yamasaki*
*Department of Pharmaceutical Botany and Pharmacognosy, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
Abstract
A new tricyclic iridoid glucoside, rothwittioside, was isolated from the aerial part of Rothmannia wittii, along with four known iridoid glucosides, macrophylloside, gardenoside, 6α-hydroxygeniposide and 6β-hydroxygeniposide. The structural elucidations were based on analyses of spectroscopic data.
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■ Formation of Five- and Six-membered Heterocyclic Ring by Radical Cyclization
Krishnna C. Majumdar* and Pradipta Kumar Basu
*Department of Chemistry, University of Kalyani, Kalyani 741 235, West Bengal, India
Abstract
This brief review describes the syntheses of different five- and six-membered heterocyclic rings in various compounds by radical cyclization.