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. 75, No. 3, 2008
Published online: 20th November, 2007
■ Organocatalytic Asymmetric Synthesis Using Proline and Related Molecules. Part 1
Hiyoshizo Kotsuki,* Hideaki Ikishima, and Atsushi Okuyama
*Laboratory of Natural Product Chemistry, Faculty of Science, Kochi University, Akebono-cho, Kochi 780-8520, Japan
Abstract
Organocatalytic asymmetric synthesis has been extensively studied and several important procedures for preparing optically active organic compounds have been developed. Research in this area has progressed rapidly in the last ten years. This review addresses the most significant advances in asymmetric synthesis using proline and related chiral organocatalysts mainly focusing on aldol reactions from the viewpoint of synthetic interests. This includes (1) proline-catalyzed aldol reactions, (2) proline-related chiral catalysts, and (3) other types of amino acid catalysts.
Published online: 16th November, 2007
■ Synthesis and Spectroscopic Properties of 2,5-Bis(benzoazol-2-yl)pyrazines
Ryota Saito,* Shinnosuke Machida, Saori Suzuki, and Akira Katoh
*Department of Materials and Life Science, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan
Abstract
A class of p-conjugated 2,5-bis(benzoazol-2-yl)pyrazine dyes have been synthesized in which 2,5-bis(benzimidazol-2-yl)pyrazine (1) exhibits strong fluorescence in solution. The enhanced fluorescence of 1 with a base leads to future applications such as anion sensing feasible upon chemical modification.
Published online: 16th November, 2007
■ A Facile Synthesis of 4-Aryl-5-alkoxycarbonyl-6-hydroxy-6-methyl-4,5,6,7-tetrahydro-3-hydroxy-2-(pyridin-2-yl)indazoles and Their NMR Characterizations
Shanmugasundaram Amirthaganesan, Gopalakrishnan Aridoss, Young Hwan Park, Jong Su Kim, Se Mo son, and Yeon Tae Jeong*
*Division of Mage and Information Engineering, Pukyong National University, Busan 608-739, Korea
Abstract
A series of N-pyridinyl tetrahydroindazoles have been synthesized by a convenient and regioseletive method by taking cyclic β-ketoesters as scaffolds. An optimum reaction condition was achieved by monitoring the reaction in different reaction condition. One and two dimensional NMR spectroscopic investigations evidenced the formation and structure of the compounds. Besides, all the compounds have been achieved as a single isomer with pyridyl group at N(2). A suitable reaction mechanism was proposed.
Published online: 16th November, 2007
■ Synthesis of the Azathioprine Analogs
Alicja Kowalska* and Krystina Pluta
*Department of Organic Chemistry, The Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowiec, Poland
Abstract
The effective synthesis of the azathioprine analogs - 2-subsituted derivatives of 7-methyl-6-(1-methyl-4-nitroimidazol-5-ylthio)purines 5 has been achieved by the reaction of 2-subsituted 6-purinethiones 4 with 5-chloro-1-methyl-4-nitroimidazole in ethanol. In the case of 7-methyl-2,6-dithioxanthine 4j, reaction in DMF gave di(imidazolyl) product 5l. The key step in this synthesis was preparation of the appropriate 2-substituted 6-purinones 2 and 6-chloropurines 3 which were further converted to 6-purinethione 4.
Published online: 4th December, 2007
■ Reaction of 1,3-Oxathiin-6-ones with Bases: Synthesis of 4-Mercapto-2-pyrone
Kentaro Okuma* and Masahiro Koda
*Department of Chemistry, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
Abstract
The reaction of 4-aryl-1,3-oxathiin-6-one 3,3-dioxide 3c with secondary amine gave cinnamamides 6 and ammonium sulfinates 7. On the other hand, the reaction of 4-methyl-1,3-oxathiin-6-one 1b with LDA, followed by the addition of benzoyl chloride, gave corresponding phenacyldioxenone 8a and 5-benzoyl-4-methyl-1,3-thiodioxenone 9 in nearly 1:1 ratio, whereas the reaction with 1-benzoyl-1,2,3-benzotriazole gave only 8a in 78% yield. Thermolysis of 8a gave the corresponding 4-mercapto-2-pyrone 4a in 62% yield.
Published online: 30th November, 2007
■ Pyrolytic Study of Cyclic 2-Azidoketones
Chin-Hsing Chou,* Li-Tse Chu, I-Ying Chen, and Bo-Jian Wu
*Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan, R.O.C.
Abstract
Flash vacuum pyrolysis of 2-azidocyclohexanone (1) gave a condensed dimer (6), a ring expanded product (7) and 2-methylpyridine (8). On the other hand, pyrolysis of 2-azidocyclopentanone (4) and 2-azido-cycloheptanone (5) gave ring expanded products (12) and (13), respectively, as the main products.
Published online: 7th December, 2007
■ Chlorotrimethylsilane Mediated Synthesis of 5-(2-Hydroxybenzoyl)pyrimidines from 3-Formylchromones
Sergey V. Ryabukhin,* Andrey S. Plaskon, Dmitriy M. Volochnyuk, Sergey E. Pipko, and Andrey A. Tolmachev
*Enamine Ltd. 23 A. Matrosova st., 01103 Kyiv, Ukraine
Abstract
The recyclization of 3-formylchromones with a variety of 1,3-NCN-binucleophiles promoted by chlorotrimethylsilane was investigated. A simple and flexible general procedure for the synthesis of series of 5-(2-hydroxybenzoyl)pyrimidines and their heterofused analogues was proposed. A set of pyrimidines was obtained in high preparative yields.
Published online: 22nd November, 2007
■ A Facile Synthesis of 1,3-Dihydroisobenzofurans Using Iodocylization of 2-Vinylbenzyl Alcohols
Kazuhiro Kobayashi,* Kazuaki Shikata, Shuhei Fukamachi, and Hisatoshi Konishi
*Department of Materials Science, Faculty of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan
Abstract
An efficient route for the preparation of 1,3-dihydroisobenzofurans based on the iodine-mediated cyclization of 2-vinylbenzyl alcohols, which can be prepared feasibly by reactions of 2-vinylphenyllithiums with carbonyl compounds, is reported. Substitution reactions of the iodo moiety of the resulting 1-(iodomethyl)-1,3-dihydroisobenzofurans with tributyltin hydride and sodium thiolates are also described.
Published online: 11th December, 2007
■ Synthesis and Bioactivity of Novel Bisphosphonate Derivatives
B. Hari Babu, G. Syam Prasad, M. F. Stephen Babu, Pallamreddy Haranath, S. Hemadri Reddy, and C. Naga Raju*
*Department of Chemistry, Sri Venkateswara University, Tirupati-517502, India
Abstract
Synthesis of novel bis-(2,10-dimethyl-4,8-di-t-butyl-12H-6-oxido-dibenzo[d,g] [1,3,2] dioxaphosphocin -6-yl) 2/3/4-substituted phenyl / heteroaryl-methanes were accomplished by Pudovic reaction. Addition of an equimolar quantities of 2,2’-methylene-bis (6-tert-butyl-4-methyl phenol) 1 and EtOH to PCl3 afforded cyclic condensation product. This on reaction with respective aldehydes followed by treatment with phosphorus (III) monochloride of 1, corresponding bisphosphonate intermediates were formed which on subsequent stirring at reflux temperature rearranged from P(III) to P(V) state.
Published online: 11th December, 2007
■ Synthesis of 4’-Thiopurine Nucleosides Using Hypervalent Iodine Compounds
Naozumi Nishizono,* Kayo Soma, Ryosuke Baba, Minoru Machida, and Kazuaki Oda*
*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
Abstract
The reaction of a silylated purine base with thiofuranoid using phenyl iodosyl bis(trifluoroacetate) gave 4’-thio purine nucleosides.
Published online: 14th December, 2007
■ Synthesis and Characterization of Some Tetracyclic Spermine Derivatives of Cyclotriphosphazene: The First Examples of Dispiransa Derivatives
Gönül Yenilmez Çiftçi,* Esra Tanriverdi, and Yunus Zorlu
*Department of Chemistry, Gebze Institute of Technology, Gebze 41400, Kocaeli, Turkey
Abstract
The synthesis and characterization is reported of a series of dispiransa cyclophosphazene derivatives based on the known compound N3P3X2[HN(CH2)3N(CH2)4N(CH2)3NH], (2) (where X = Cl), to give a number of new compounds (3a-g) in which X = Ph, PhS, PhNH, PhO, MeO, EtO, CF3CH2O, respectively. Two synthetic routes were utilized: (i) reaction of spermine with the appropriate disubstituted cyclophosphazenes (1) to give compounds (3a-c) and (ii) using the chloro-precursor (2) in nucleophilic substitution reactions with nucleophiles to give compounds (3d-g). The structures of the compounds were determined by elemental analysis, mass spectrometry, 1H and 31P NMR spectrocsopy.
Published online: 14th December, 2007
■ Flavonoidal C-Glycosides from Abutilon pakistanicum
Munawar Hussain, Durey Nayab Zahra, Abdul Malik, Asam Ejaz, Hina Siddiqui, Muhammad Iqbal Choudary, and Zaheer Ahmed*
*International Center for Chemical and Biological Sciences, H. E. J. Research Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
Two new flavonoidal C-glycosides provisionally named as pakistoside A (1) and pakistoside B (2) have been isolated from the aerial parts of Abutilon pakistanicum. Their structures have been assigned through detailed spectral analyses including 2D-NMR techniques. In addition kaempferol, kaempferol-3-O-α-L-rhamnopyranoside and luteolin are isolated for the first time from this plant.
Published online: 16th November, 2007
■ Facile One-Pot Reaction for the Regioselective Syntheses of 2H-[1,2,4]Thiadiazolo[2,3-a]pyrimidine Derivatives
Guohua Liu,* Mei Yao, Yunning Xue, Haibin Fang, and Xiqowei Cao*
*Department of Chemistry, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234, P. R. China
Abstract
A convenient and rapid method for the preparation of 2H-1,2,4-thiadiazole[2,3-a]pyrimidine derivatives 3a-3e was developed. The investigations of their regioselective syntheses through a comparison of the different substituted groups on the pyrimidine ring using a semi-empirical MO calculation and an X-Ray crystallographic analysis was also discussed.
Published online: 7th December, 2007
■ Three New Furanosesquiterpenoids from Bombax malabaricum and Revised NMR Assignment of Hibiscone C
Xiaohui zhang, Shuwei Zhang, and Lijiang Xuan*
*State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institute for Biological Sciences, Chinese Academy of Science, 555 Zuchongzhi Rd., Zhangjiang Hi-Tech Park, Shanghai, 201203, China
Abstract
Hibiscone C (1), and three new furanosesquiterpenoids, namely bombaside, bombaxone, and 7β-O-β-glucopyranosyl bombaxone (2-4), were isolated from the roots of Bombax malabaricum. Their structures were characterized by extensive 1D and 2D NMR spectroscopic analyses. The NMR assignment of hibiscone C was revised.
Published online: 7th December, 2007
■ Silica Sulfuric Acid-Activated Poly-1,3,-dichloro-5-methyl-5(4’-vinylphenyl)hydantoin (PDCVH) as an Effective Reagent for Oxidation of 1,3,5-Trisubstituted 2-Pyrazolines Both under Microwave Irradiation and Thermal Condition
Davood Azarifar,* Behrooz Maleki, and Mehrnaz Setayeshnazar
*Faculty of Chemistry, Bu-Ali Sina University, Zip Code 65178, Hamedan, Iran
Abstract
Oxidation of 1,3,5-trisubstituted 4,5-dihydro-1H-pyrazoles to the corresponding pyrazoles has been achieved by utilizing silica sulfuric acid-activated poly-1,3-dichloro-5-methyl-5(4’-vinylphenyl)hydantoin in EtOH under both microwave irradiation and conventional thermal condition at room temperature with good yields.
Published online: 14th December, 2007
■ A Simple Synthesis of α-Nitro-δ-keto Nitrile
Nagatoshi Nishiwaki,* Tomoko Nogami, and Masahiro Ariga*
*Department of Chemistry, Osaka Kyoiku University, Asahigaoka 4-698-1, Kashiwara, Osaka 582-8582, Japan
Abstract
α-Nitro-δ-keto nitrile was effectively synthesized in one-pot from pyridinium salt of nitroisoxazolone by ring opening reaction followed by condensation with two molecules of acetone via pyrrolidinium salt of 2,4-di-aci-nitropentanedinitrile. The obtained α-nitro-δ-keto nitrile has a highly acidic hydrogen in addition to multi-functionality. These structural features are considered to be useful for the syntheses of polyfunctionalized compounds.