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. 55, No. 3, 2001
Published online:
■ Novel Synthesis of Pyrrolo[2,1-a]isoquinoline Using the Reaction of Isoquinolinium Salts with Active Methylene Compounds
Reiko Fujita,* Noriyuki Watanabe, and Hiroshi Tomisawa
*Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
Abstract
2-Alkyl-1-methylthioisoquinolinium salts were easily prepared from 2-alkyl-1(2H)-isoquinolones via 2-alkyl-1(2H)-thioisoquinolones in two steps. Under mild conditions, the reaction of 2-alkyl-l-methylthioisoquin-olinium salts with active methylene compounds in the presence of sodium hydride afforded 2-alkyl-1-(substituted methylene)isoquinolines in good yields. The cyclization of 2-benzylisoquinolines using acetic anhydride produced the pyrrolo[2,1-a]isoquinolines. Further, the reaction of 1-chloro-2-phenacylisoquinolinium salt with active methylene compounds afforded the pyrrolo[2,1-a]isoquinolines in one pot.
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■ Unsymmetrical 4,6-Diamino-2-methyl-5-nitropyrimidine Synthesis via 4,6-Bis(tosylates)
Gary A. Cain* and James P. Beck
*Experimental Station E336/109, Chemical and Physical Sciences Department, DuPont Pharmaceuticals Company, P.O.Box 80336, Wilmington, DE 19880-0336, U.S.A.
Abstract
Chlorides have traditionally been used as leaving groups for the introduction of 4- and 6-heteroatomic substituents onto pyrimidines. Use of 4,6-dichloro-2-methyl-5-nitropyrimidine allows the sequential introduction of different 4- and 6-heteroatomic substituents onto this core; however, this reagent is highly hazardous to handle. We have found that the analogous 4,6-bis(tosylate) offers a less hazardous substance which undergoes the same nucleophilic aromatic substitution chemistry as the dichloride, including sequential introduction of different nucleophiles.
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■ Synthesis of Crownophane Possessing Pyridine Moieties on the Aromatic Nuclei (Pyridine-Lariat Crownophane): A Crownophane Exhibiting Perfect Selectivity toward Ag+
Seiichi Inokuma, Koichi Kimura, Takashi Funaki, and Jun Nishimura*
*Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan
Abstract
A novel crown compound with two hydroxy groups on the aromatic nuclei was conveniently prepared by means of intramolecular [2 + 2] photocycloaddition of styrene derivertives. It was readily converted to the title compound (1). In the liquid-liquid extraction of heavy metal cations, 1 showed perfect selectively and high efficiency toward Ag+. From ESI-MS analysis, the compound was found to form a 1:1 with Ag+ ion in MeCN-H2O homogeneous system.
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■ Asymmetric Allylic Alkylation Using Planar Chiral Phosphine-Hydrazone Ligands
Takashi Mino,* Teruhiro Ogawa, and Masakazu Yamashita
*Department of Materials Technology, Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
Abstract
Palladium-catalyzed asymmetric allylic substitution of 1,3-diphenyl-2-propenyl acetate (3) with a dimethyl malonate-BSA-lithium acetate system has been successfully carried out in the presence of chiral ferrocene hydrazone such as (S)-α-(diphenylphosphino)ferrocenecarboxaldehyde SAMP hydrazone (DPPFA-SAMP) ((S,S)-2a) in high yields with high enan-tioselectives (up to 96% ee).
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■ Nucleophilic Substitution Reaction on the Nitrogen of Indole Nucleus: Formation of 1-(Indol-3-yl)indoles upon Reaction of 1-Hydroxyindoles with Indole in Formic Acid
Masanori Somei,* Fumio Yamada, Toshikatsu Hayashi, Aya Goto, and Yoshitomo Saga
*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan
Abstract
1-(Indol-3-yl)indoles are obtained in excellent to good yields by the reaction of 1-hydroxyindoles with indole in 85% formic acid. Their structures are determined by X-Ray crystallographic analysis and chemical correlations. The unprecidented SN2 mechanism on the indole nitrogen is proposed.
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■ A New Sandmeyer Iodination of 2-Aminopurines in Non-aqueous Conditions: Combination of Alkali Metal Iodide and Iodine as Iodine Sources
Naoki Ozeki,* Naoyuki Shimomura, and Hitoshi Harada
*Process Research Laboratories, Eisai Co., ltd., 22 Sunayama, Hasaki, Kashima-gun, Ibaraki 314-0255, Japan
Abstract
An effective method for iodination using 2-aminopurines in non-aqueous conditions was found. The optimal conditions involved the combination of isopentyl nitrite, cuprous iodide, alkali metal iodide and iodine in ethylene glycol dimethyl ether at 60°C.
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■ Novel Ring Transformation of Dihydroselenines to Selenabicyclo[3.1.0]hexenes
Eiji Honda, Shin-ichi Watanabe, Tatsunori Iwamura, and Tadashi Kataoka*
*Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan
Abstract
Treatment of 2-bromo-2,6-dicyano-2,3-dihydroselenine (6) with triethylamine in ethanol gave 2-selenabicyclo[3.1.0]hex-3-ene (7) in 77% yield. Reaction of 7 with benzyne formed benzoselenophene (11) in 35% yield. Methylation of 7 with methyl triflate produced Se-methylselenonium salt (12), which was transformed into amide derivatives (16) and (17). Compound (7) was converted into alkynylcyclopropane (13) via selenonium salt (12).
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■ Synthesis and Cycloaddition Reactions of New Captodative Olefins, N-Substituted 5-Alkylidene-1,3-oxazolidine-2,4-diones
Adriana Benavides, Rafael Martínez, Hugo A. Jiménez-Vázquez, Francisco Delgado, and Joaquin Tamariz*
*Departamento de Químíca Orgánica, Escuela Nacional de Ciencias Biológicas, I. P. N., Prol. Carpio y Plan de Ayala S/N,11340, Mexico, D.F.
Abstract
An efficient and straightforward synthesis of the new captodative olefins N-substituted 5-alkylidene-1,3-oxazolidine-2,4-diones (8-10) is described, by a chemoselective oxidative cleavage of the novel exo-2-oxazolidinone dienes (3, 4, and 7), respectively. A study of the reactivity and selectivity of olefins (8-10), was carried out in Diels-Alder cycloadditions to cyclic and unsymmetric acyclic olefins. In all reactions, the corresponding adducts were obtained in high stereo- and regioselectivity. These results have been rationalized in terms of FMO theory by ab initio calculations. 1,3-Dipolar additions of nitrones to olefin (8a) were also highly regioselective, yielding only the C-5 substituted adducts.
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■ New Spiramines from Spiraea japonica var. ovalifolia
Guo Ying Zuo, Hong Ping He, Xin Hong, Wei Ming Zhu, Xiao Sheng Yang, and Xiao Jiang Hao*
*Laboratory of Phytochemistry, Kunming Institute of Botany, The Chinese Academy of Sciences, Kunming, Yunnan 650204, China
Abstract
Eleven atisine-type diterpene alkaloids, including five new ones 19-O-deethylspiramine N (1), 15-deacetylspiramine S (2), spiramine Z-2 (3), spiramine Z-3(4), deacetylspiramine F(5), and six known ones, spiramines A, B, C, D, F(6), H were isolated from the air dried Spiraea japonica var. ovalifolia.
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■ Synthesis of Xestomanzamines A and B
Brigitte E. A. Burm, Peter Blokker, Edwin Jongmans, Erwin van Kampen, Maritn J. Wanner, and Gerrit-Jan Koomen*
*Laboratory of Organic Chemistry, Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands
Abstract
Synthetic pathways are described for the synthesis of two naturally occurring β-carbolines, xestomanzamine A and B. The synthesis of aromatic xestomanzamine A was most conveniently achieved by way of a Grignard reaction in dichloromethane. This route is suitable for the synthesis of analogues with modifications in the imidazole ring of xestomanzamine A. Xestomanzamine B, an oxidation-sensitive dihydro-β-carboline, was prepared by Pictet-Spengler condensation of tryptamine with a vicinal tricarbonyl substituted imidazole.
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■ A New Neo-Clerodane Diterpenoid from Salvia gesneraeflora (Labiatae)
Baldomero Esquivel* and Eugenio A. Flores
*Instituto de Quimica, Universidad Nacional Autónama de Mexico, Circuito Exterior, Ciudad Universitaria, Coyoacán 04510 Mexico, D.F., Mexico
Abstract
The aerial parts of Salvia gesneraeflora afforded, besides salviarin and gensnerofolin B, a new neoclerodane named 7α-acetoxy-7,8α-dihydrogensnerofolin B. Its structure was elucidated by spectroscopy methods and chemical correlation with gensnerofolin B.
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■ A Study of the Photochemical Isomerization in β-Lactam Rings
Roberto Alcázar, Pedro Ramírez, Rubén Vincente, María J. Mancheño, Miguel A. Sierra, and Mar Gómez-Gallego*
*Departamento de Química Orgánica I., Facultad de Química., Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
The cis to trans or trans to cis photoisomerization of 2-azetidinones (1) is reported. The outcome of the photochemical process is controlled by the substitution on the nitrogen atom and by the ability of the substituents at C3 and C4 positions to stabilise radicals. N-Aryl-2-azetidinones are unreactive even after several hours of UV-light irradiation. N-Alkyl-2-azetidinones cleanly isomerize under the same conditions, providing a smooth procedure for the ring isomerization of β-lactams.
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■ Synthesis and Solution Behavior of Water-soluble Bis-porphyrins
Hisatsugu Okada,* Hiroyasu Imai, and Yoshio Uemori
*School of Pharmacy, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan
Abstract
A series of water-soluble bis-porphyrins in which two porphyrin (5-(2-amidophenyl)-10,15,20-tris(N-methyl-4-pyridiniumly)porphyrin) units were linked by a methylene chain with various lengths (-NHCO-(CH2)n-CONH-, n = 1, 3, 5, 7 and 11) were synthesized and characterized by UV-visible and 1H-NMR spectroscopy. The conformations of the bis-porphyrins in solution were estimated from calculation on the basis of their ring-current shifts. The self-association behavior of the bis-porphyrins in aqueous solution (at 25°C, pH 7.0, μ= 0.045) was also reported.
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■ A Radical Synthetic Approach to the New Potentially Bioactive Pyrimidinones
Serge Djekou, Armand Gellis, José Maldonado, Michel P. Crozet, and Patrice Vanelle*
*Laboratoire de Chimie Organique, Faculté de Pharmacie, Université de la Méditerranée, 27, Boulevard Jean Moulin, 13385 Marseille Cedex 05, France
Abstract
2-Chloromethyl-8-methyl-3-nitro-4H-pyrido[1,2-a]pyrimidin-4-one was shown to react with various nitronate or malonate anions under mild conditions to give potentially bioactive nitro-4H-pyrido[1,2-a]pyrimidin-4-ones. Extension to other anions centred on S or O atom allows to generalize this synthetic procedure.
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■ A Singlet Oxygen Mediated New Access to Hydroxyindolenine-Catharanthine Derivatives by Two Sequential Oxidations
Clotilde Ferroud* and Patrice Rool
*Laboratoire de Chimie Organique associe au CNRS, Conservatoire Naitonal des Arts et Metiers, 292, rue Saint Martin, 75141 Paris Cedex 03, France
Abstract
Formation of hydroxyindolenine derivatives by photoinduced oxidation by singlet oxygen of intermediate 3β-cyanocatharanthine (3) allows us to synthesize under mild conditions new alkaloids derivatives, 3β-cyano-7β-hydroxyindolenine-catharanthine (5), 3β-cyano-7β-hydroxyindolinecatharanthine (6) and 7β-hydroxy-indolenine-catharanthine (7), bearing protected indole moities.
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■ Five New Oligostilbenes with One or Two Dihydrofurans from the Stem Bark of Vatica rassak
Tetsuro Ito, Toshiyuki Tanaka,* Yoshimi Ido, Ken-ichi Nakaya, Munekazu Iinuma, Yoshikazu Takahashi, Hiroshi Naganawa, and Soedarsono Riswan
*Gifu Prefectrual Institute of Health and Environmental Sciences, 1-1 Nakafudogaoka, Kakamigahara, Gifu 504-0838, Japan
Abstract
From the stem bark of Vatica rassak, five new stilbenoids (vaticanols E, F and vaticasides A-C) were isolated. The structures including the relative configuration were established on the basis of spectroscopic analysis.
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■ Enantioselective Synthesis of 2- and 3-Benzofuryl β-Amino Alcohols
Marek Zaidlewicz,* Aldona Chechlowska, Andrzej Prewysz-Kwinto, and Andrzej Wojtczak
*Facutly of Chemistry, Nicolaus Copernicus University, 7 Gagarin Street, 87-100 Torun, Poland
Abstract
Enantioselective reduction of 2- and 3-bromoacetylbenzofurans with (-)-B-chlorodiisopinocampheylborane produced the corresponding bromohydrins which were transformed into (S)-(benzofuran-2-yl)oxirane of 72% ee and (S)-(benzofuran-3-yl)oxirane of 71% ee, respectively. The epoxides treated with primary alkylamines gave the corresponding (S)-1-(benzofuran-2- and -3-yl)-2-(alkylamino)ethanols.
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■ Regiospecific Alkylation of 5-Substituted 2-Acylamino-1,3,4-thiadiazoles
Nam Sook Cho,* Hye Jeong Hwang, Jin-Gyu Kim, and Il-Hwan Suh
*Department of Chemistry, College of Natural Sciences, Chungnam National University, Taejon 305-764, Korea
Abstract
5-Substituted 2-acylamino-1,3,4-thiadiazoles (2 and 3b) are quantitatively and regiospecifically alkylated with alkyl bromide at the 3-position nitrogen (endo-products) rather than at the 2-position amide-nitrogen (exo-products) under basic conditions. This alkylation required more than 1.5 equivalents of base and more than four equivalents of alkyl bromide. The structures of the products, 5-substituted 2-acylimino-3-alkyl-1,3,4-thiadiazolines (4 and 5b2), were clearly established by spectroscopic data. Especially, the structure of 3-ethyl-5-ethylthio-2-p-toluoylimino-1,3,4-thiadiazoline (4d1) was proven by X-Ray crystallography.
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■ Bischler-Napieralski Cyclization of N-[2- (2-Bromo-5-hydroxy-4-methoxyphenyl)ethyl]-N-[(S)-1-phenylethyl]-2-(2-bromo-4,5-dimethoxyphenyl)acetamide Accompanied by Elimination of Chiral Auxiliary
Kumiko Miyatani, Mariko Ohno, Kazuyo Tatsumi, Yoshitaka Ohishi,* Jun-ichi Kunitomo, Ikuo Kawasaki, Masayuki Yamashita, and Shunsaku Ohta
*Faculty of Pharmaceutical Science, Mukogawa-Women's University, 11-68 Koushien Kyuban-Cho, Nishinomiya, Hyogo 663-8179, Japan
Abstract
N-[2-(2-bromo-5-hydroxy-4-methoxyphenyl)ethyl]-N-[(S)-1-phenylethyl]-2-(2-bromo-4,5-dimethoxyphenyl)acetamide (5) was cyclized under N-dealkylation at the 2-position to the racemic 1-benzyl-1,2,3,4-tetrahydroisoquinoline derivatives (6) by the Bischler-Napieralski cyclization followed by NaBH4 reduction (Polniaszek’s method).