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. 63, No. 2, 2004
Published online: 15th December, 2003
■ Selective Phototransformation of Hydroxy-substituted Aromatic Nitrones into N,N-Diarylformamide Derivatives Showing a Novel Conformational Isomerism
Harunobu Kondo, Kenta Tanaka , Kanji Kubo, Tetsutaro Igarashi, and Tadamitsu Sakurai*
*Departmnet of Applied Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
Abstract
On irradiation in acetonitrile at 366 nm, photorearrangements of the title aromatic nitrones (1) proceeded to give selectively N,N-diarylformamides, which showed a novel conformational isomerism without undergoing large substituent, solvent, and temperature effects. An analysis of substituent and solvent effects on the product distribution confirmed that a hydrogen-bonding interaction with the ring nitrogen in oxaziridine intermediates plays a crucial role in inducing the selective transformation of 1 into the corresponding formamide derivatives.
Published online: 8th December, 2003
■ On the Synthesis and Characterization of 3-Arylamino-7-nitro-2H-1,4-benzoxazines
Roxana Barbieru, Walter Grahn, Horst Hartmann,* Dominic Pratt, and Peter G. Jones
*Department of Chemistry, University of Applied Sciences, Geusaer Str., D-06217 Merseburg, Germany
Abstract
By the reaction of 7-nitro-2H-1,4-benzoxazin-3(4H)-one with POX3 (X = Cl, Br) and subsequent addition of arylamines, a series of coloured 3-arylamino-7-nitro-2H-1,4-benzoxazines have been synthesized and spectroscopically characterized in order to investigate their availability as hair colorants.
Published online: 21st November, 2003
■ Synthesis and Structural Studies of 3-Acylamino-4-amino-2,3-dihydro-2-iminothiazole-5-carboxylates and 4-Acylhydrazino-2-aminothiazole-5-carboxylates
Maria Teresa Cocco,* Cenzo Congiu, Valentina Onnis, and Sandra Ianelli
*Department of Toxicology, University of Cagliari, Via Ospedale 72, I-09124 Cagliari, Italy
Abstract
The preparation of thiazole derivatives through reactions of ethyl 3-amino-3-acylhydrazinopropenoates (1) with inorganic thiocyanates and thiourea was investigated. The reaction of 1 with sodium thiocyanate, in acetic acid in the presence of bromine, afforded ethyl 3-acylamino-4-amino-2,3-dihydro- 2-iminothiazole-5-carboxylates (3) selectively. On reacting the same compounds (1) with thiourea, in acetic acid and in the presence of bromine, 4-acylhydrazino-2-aminothiazole-5-carboxylates (4) were yielded. The structure of the representative compound (3c), ethyl 4-amino-3-benzoyl- amino-2,3-dihydro-2-iminothiazole-5-carboxylate has been solved by means of X-Ray crystallographic data analysis.
Published online: 8th December, 2003
■ The Asymmetric Synthesis of Linear Dihydropyrano Coumarins for Alzheimer’s Disease
Shi Shun, Ling-Yi Kong,* Han-Qing Zhang, Shan-An He, and Masatake Niwa
*Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, China
Abstract
Ca2+ antagonistic and acetylcholinesterase (AchE) inhibitory activity-guided cis-3’S, 4’S-disubstituted linear dihydropyranocoumarins were synthesized asymmetrically. The syntheses were performed with resorcinol or 2-methylresorcinol, enantioselectivity was chosen AD-mix-β to dihydroxylate asymmetrically. All products were screened against AchE in vitro and one showed potential inhibitory activity.
Published online: 8th December, 2003
■ Facile Synthesis of Biologically Active Heterocycles by Indium-induced Reactions of Aromaic Nitro Compounds in Aqueous Ethanol
Bimal K. Banik,* Indrani Banik, Susanta Samajdar, and Mary Wilson
*Department of Molecular Pathology, Box-089, M. D. Anderson Canaer Center, The University of Texas, 515 Holcombe Blvd. , Houston, TX 77030, U.S.A.
Abstract
Indium/ammonium chloride-induced reduction of aromatic nitro compounds to aromatic amines in aqueous ethanol was developed. Useful chemo-selectivity was observed in the reduction reaction. This method was extended to reductive cyclization and rearrangement toward the synthesis of various biologically active heterocycles, including quinoline, oxazines, quinalonones, and phenanthridine in excellent yield. The oxophilicity of indium metal influenced the reaction in aqueous ethanol. Metals like zinc and tin were not effective in promoting this kind of reactions under the present environmentally friendly conditions.
Published online: 8th December, 2003
■ Etherificaiton of Heterocyclic Compounds by Nucleophilic Aromatic Substitutions under Green Chemistry Conditions
Matthieu Lloung, André Loupy,* Sylvain Marque, and Alain Petit
*Laboratoire des Réactions Sélectives sur Supports, ICMMO, CNRS UMR 8615, Université de Paris-Sud, Bâtiment 410, 91405 Orsay Cedex, France
Abstract
Solid-liquid phase transfer catalysis coupled with microwave irradiation was shown to be an efficient method for SNAr reaction of halogenated quinoline and pyridine with alkoxides and phenoxides. Whereas for phenoxylation there is no need for any solvent, the addition of small amount of non-polar solvent is necessary during methoxylation for accurate monitoring of temperatures. Yields and conditions involved here constitute a noticeable improvement over classical methods within the frame of Green Chemistry. Specific MW effects were evidenced for phenoxylation and interpreted in terms of late position of the transition state along the reaction coordinates.
Published online: 15th December, 2003
■ Reaction of 2-Benzotelluropyrylium Salts with Organocopper Reagnets: Introduction of a Carbon Functional Group at the C-1 Position of the Telluropyrylium Cation Ring
Haruki Sashida,* Hirohito Satoh, and Kazuo Ohyanagi
*School of Pharmacy, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan
Abstract
3-tert-Butyl-2-benzotelluropyrylium salt (13A) react with lithium dialkyl(phenyl)copper to give in good yield the corresponding isotellurochromenes (15A) having a carbon functional group at the C-1 position. Similarly, the 1-substituted isoselenochromenes (15B) and the 4-substituted tellurochromene (19) were also prepared from the corresponding pyrylium salts (13B, 18). The obtained isotellurochromenes (15A) were easily converted into the corresponding 2,4-disubstituted 2-benzotelluropyrylium salts (20) by the treatment with triphenylcarbenium tetrafluoroborate (Ph3C+ BF4-).
Published online: 8th December, 2003
■ Novel Synthesis, Properties, and Structural Characteristics of 1,6-Dialkyl-pyrimido[5,4-e][n](2,4)pyridinophane-5,7-(1H,6H)-diones
Makoto Nitta,* Hiromi Kanda, Hiroyuki Yamamoto, and Shin-ichi Naya
*Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Abstract
Novel synthesis of the 1,6-dialkylpyrimido[5,4-e][n](2,4)pyridinophane-5,7(1H,6H)-diones (n = 11, 9, 6) (5,7-polymethylene-substituted 8-alkylpyrido[2,3-d]pyrimidine-2,4(3H,8H)-diones) consists of allowing 3-methyl-6-benzylaminouracil to react with cycloalk-2-enones. Their chemical and electrochemical properties as well as structural characteristics are studied on the basis of their spectroscopic properties, cyclic voltammetry, X-Ray analysis, and theoretical calculations. Deformation of the pyridine ring of a [6](2,4)pyridinophane derivative is observed by X-Ray analysis. Furthermore, isolation of a dihydrogenated [5](2,4)pyridinophane derivative and its unsuccessful dehydrogenation reaction leading to the first example of a [5](2,4)pyridinophane derivative are investigated as well.
Published online: 15th December, 2003
■ Synthesis and Complexing Properties of Crownophanes Possessing Carboxyl Group
Seiichi Inokuma, Takashi Funaki, Daisuke Hara, and Jun Nishimura*
*Department of Chemistry, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan
Abstract
A new series of crown compounds bearing two carboxyl groups (2a-c; crownophanedicarboxylic acids) were prepared via intramolecular [2 + 2] photocycloaddition of bis-styrene derivatives. In the liquid-liquid extraction, crownophanedicarboxylic acids (2a-c) showed a low affinity toward alkali metal cations, though both 2b and 2c showed an extraordinary high affinity toward zinc cation among heavy metal cations examined.
Published online: 26th December, 2003
■ New Cytotoxic Norditerpene Dilactones from Leaves of Podocarpus macrophyllus var. maki
Hyun-Sun Park, Noriyuki Kai, Haruhiko Fukaya, Yutaka Aoyagi, and Koichi Takeya*
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
Four new nor- and bisnorditerpene dilactones, rakanmakilactones G(1), H-J (3-5), one new norditerpene dilactone apioside (2), and one new totarane diterpene (6) were isolated from a MeOH extract of the leaves of Podocarpus macrophyllus D. Don var. maki Endl. of the family Podocarpaceae. The structures of 1-6 were established by spectroscopic studies, including 1D and 2D NMR spectral analysis, and single-crystal X-Ray crystallographic analysis. Those rakanmakilactones from this plant were found to have a cytotoxic effect on P388 murine leukemia cells.
Published online: 15th December, 2003
■ Lipoxygenase Inhibiting Flavonoids from Indigofera hetrantha
Aziz-ur-Rehman, Abdul Malki,* Naheed Riaz, Habib Ahmad, Sarfraz Ahmad Nawaz, and Muhammad Iqubal Choudhary
*International Centre for Chemical Sciences, H. E. J. Research Institute of Chemistry, University of Karachi, Pakistan
Abstract
Hetranthins A (1) and B (2), new flavonoids, together with known compounds 7,3’,4’-trihydroxyflavanone (3) and 3,5,7,3’,4’-pentahydroxyflavanone (4) have been isolated from the ethyl acetate fraction of Indigofera hetrantha. Their structures have been assigned on the basis of spectral analysis. Compounds (1-4) showed inhibitory activity against lipoxygenase enzyme.
Published online: 8th December, 2003
■ An Efficient Synthesis of 6,6-Dimethyl-2-(4-nitrophenyl)-1-(R-phenyl)-4,5,6,7-tetrahydro-1H-4-indolones Using a Solid Sulfated Zirconia as Catalyst
Guillermo Negrón,* Deyanira Ángeles, Leticia Lomas, Ángeles Martínez, Manuel Ramírez, and Roberto Marínez
*Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitatria, CoyoacÁn 04510, Mexico
Abstract
Sulfated zirconium has been found to be an excellent substitute for conventional acids in the tetrahydroindolone derivatives synthesis, resulting in milder reaction conditions, bringing down reaction temperature and formulating more efficient isolation and purification procedure.
Published online: 8th December, 2003
■ Synthesis of 1H-Indazoles by Reductive Cyclization of o-Nitro-ketoximes
David K. O’Dell and Kenneth M. Nicholas*
*Department of Chemistry and Biochemistry, University of Oklahoma, Nrman, Oklahoma 73019, U.S.A.
Abstract
ortho-Nitro-ketoximes are converted to 1H-indazoles upon reaction with carbon monoxide with [Cp*Fe(CO)2]2 as catalyst.
Published online: 21st November, 2003
■ A New diterpene of Leonotis nepetaefolia
Dionne M. Boalino and Winston F. Tinto*
*Laboratory of Bioorganic Chemistry, Department of Biological & Chemical Sciences, University of the West Indies, Cave Hill Campus, P.O. Box 64, Bridgetown, Barbados
Abstract
A new labdane diterpenoid, leonotinic acid (1), possessing an α,β-butenolide unit, was isolated from the aerial parts of Leonotis nepetaefolia. It was identified on the basis of 1D and 2D NMR including 1H-1H COSY, HSQC, HMBC and T-ROESY spectroscopic techniques.
Published online: 8th December, 2003
■ Three New Mexicanolides from the Stem Bark of Swietenia mahogani Jacq.
Mona M. G. Saad, Tetsuo Iwagawa, Hiroaki Okamura, Matsumi Doe, and Munehiro Nakatani*
*Department of Chemistry and Bioscience, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
Abstract
Three new mexicanolide-type limonoids were isolated together with two known mexicanolides, 2-hydroxyswietenin and swietemahonin G, from the ether extract of the stem bark of Swietenia mahogani JACQ. (Meliaceae). The structure of these compounds was elucidated by spectroscopic means and their biological activities were also tested.
Published online: 15th December, 2003
■ Alkali Metal-mediated Synthesis of 1- and 4-Substituted N-Alkyl-1,2,3,4-tetrahydroisoquinolines
Ugo Azzena,* Luisa Pisano, and Mario Pittalis
*Department of Chemistry, University of Sassari, Via Vienna 2, I-07100 Sassari, Italy
Abstract
Reductive cleavage by electron transfer from Li or K metal of 1-alkoxy-substituted N-alkyltetrahydroisoquinolines led to the formation of organometallic derivatives. Quenching of these intermediates with electrophilic reagents afforded 1- or 4-substituted N-alkyl-1,2,3,4-tetrahydroisoquinolines, depending upon the nature of the metal.
Published online: 15th December, 2003
■ Palladium-catalyzed Carbonylation of Polychlorinated Pyridines. A Simple Laboratory Approach to Metal Catalyzed Carbonylation Reactions
John W. Hull, Jr.* and Chen W. Wang
*Chemical Sciences Process Rsearch & Development, The Dow Chemical Company, 1707 Building, Midland, Michigan 48674, U.S.A.
Abstract
The palladium-catalyzed carbonylation reactions of pentachloropyridine and 2,3,4,5-tetrachloropyridine were investigated in alcoholic or aqueous solvent. The high boiling alcohol 2-ethyl-1-hexanol was an effective carbonylation solvent above 100 °C at 1 atm of CO, representing a convenient and simple method for carrying out transition metal catalyzed carbonylation reactions using standard laboratory glassware.
Published online: 8th December, 2003
■ Glycolurils
Wanda Sliwa,* Grazyna Matusiak, and Jerzy Peszke
*Institute of Chemistry and Environmental Protection, Pedagogical University, Al. Armii Krajowej 13/15, 42-201 Czestochowa, Poland
Abstract
In the first part of the review the glycoluril dimers are described, followed by molecular clips and bowl-shaped receptors; then glycoluril capsules and at last some applications of glycolurils are presented.