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. 68, No. 3, 2006
Published online: 21st February, 2006
■ Novel Method for the Synthesis of β-Lactams by the Reaction of α-Bromocarboxylic Acids with Imines Mediated by Triphenylphosphine
Satoshi Kikuchi and Yukihiko Hashimoto*
*Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Abstract
The useful and simple method for the formation of the β-lactams by the reaction between α-bromo carboxylic acids and imines is described. This reaction was effectively mediated by triphenylphosphine or polystyryl-diphenylphosphine to give the β-lactams in good yields with high trans-selectivity.
Published online: 14th February, 2006
■ A Novel and Efficient Darzens Reaction Catalyzed by Magnesium Bromide
Shigeki Sano, Motoyuki Miyamoto, Tomoko Mitani, and Yoshimitsu Nagao*
*Faculty of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan
Abstract
The Darzens reaction of phenacyl bromide with aromatic aldehydes catalyzed by MgBr2 in the presence of an excess amount of triethylamine afforded trans-α,β-epoxy ketones in good yields.
Published online: 14th February, 2006
■ Synthesis and X-Ray Crystal Structure Determinations of Pyrrolidine-2,4-diones, 2-Iminopyrrolidin-5-ones and 1,3-Oxazine-2,4-diones Derived from Acetoacetanilides
Thomas Duff, John P. James,* and Helge Müller-Bunz
*School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
Abstract
Commercially available acetoacetanilides may, after initial alkylation, be cyclized to pyrrolidine-2,5-diones by reaction with ethyl bromoacetate or cyclized to 5-iminopyrrolidin-2-ones with chloroacetonitrile. Reaction with ethyl chloroformate gives 1,3-oxazine-2,4-diones. Several examples of these reactions using different alkyl groups are described. The structures of the products were confirmed by X-Ray crystallography.
Published online: 17th January, 2006
■ Copper Catalyzed Cyclopropanation of 1,2,3,4-Tetrahydropyridin-2-ones with Trimethylsilyldiazomethane: A Facile and Selective Synthesis of 2-Aza-3-oxobicyclo[4.1.0]heptanes
Vishal B. Sharma, Suman L. Jain, and Bir Sain*
*Chemical and Biotechnology Division, Indian Institute of Petroleum, Dehradun-248005, India
Abstract
The reactions of a series of 1,2,3,4-tetrahydropyridin-2-ones with trimethylsilyldiazomethane using catalytic amounts of copper(II) triflate in refluxing 1,2-dichloroethane yielded exclusively 3-oxo-2-azabicyclo[4.1.0]heptanes in good yields. The application of ultrasonic radiation enhanced the reaction rate and allowed the reactions to be conducted at room temperature.
Published online: 31st January, 2006
■ Asymmetric Synthesis of Flindersiachromanone Using Lipase-catalyzed Reaction
Masashi Kawasaki,* Hikaru Yoshikai, Hiroko Kakuda, Naoki Toyooka, Akira Tanaka, Michimasa Goto, and Tadashi Kometani
*Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
Abstract
The (R)- and (S)-enantiomers of flindersiachromanone (2-(2-phenylethyl)-4-chromanone) were synthesized from the enantiomerically pure 1-phenyl-5-hexen-3-ol obtained via the lipase-catalyzed enantioselective transesterification.
Published online: 21st February, 2006
■ 1-Alkyl-4-(3-pyridinylamino)quinolinium-3-thiolates and Their Transformation into New Diazaphenothiazine Derivatives
Andrzej Zieba* and Kinga Suwinska
*Department of Organic Chemistry, The Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowice, Poland
Abstract
The reactions of 5,12-dialkylthioquinantrenediinium bis-salts (1) with 3-aminopyridine yield 1-alkyl-4-(3-pyridinylamino)quinolinium-3-thiolates (2). In the presence of oxygen and hydrogen chloride, the compounds (2) undergo cyclization to 1,4-thiazine derivatives having the structure of 5-alkyl-12(H)-pyrido[2,3-e]quino[3,4-b][1,4]thiazinium salts (4). The structure of 3-thiolates (2) was analyzed using 1H NMR (NOE) and 15N NMR spectral methods. The structure of compound (4) was confirmed by X-Ray analysis.
Published online: 14th February, 2006
■ 1-Allylation of 2-Benzotelluropyrylium Salts and 2-Benzoselenopyrylium Salts by Means of Allyltin Reagents
Kazuo Ohyanagi and Haruki Sashida*
*Faculty of Pharmaceutical Sciences, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan
Abstract
3-tert-Butyl-2-benzotelluropyrylium salt (1) reacts with an equal amount of allyltributyltin to afford 1-allyl-3-tert-butyl-1H-isotellurochromene (8a) in 93 % yield. Similarly, 1-allyl-1H-isotellurochromenes (9) and isoselenochromenes (10, 11) were prepared from the corresponding pyrylium salts (2-4) in moderate to good yields.
Published online: 14th February, 2006
■ Synthesis of Cribrostatin 6 and Its Related Compounds
Shinsuke Nakahara,* Akinori Kubo, Yuzuru Mikami,* and Junji Ito
*Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
Abstract
The synthesis of cribrostatin 6 (1), which shows good biological activity as a dark blue cancer cells growth inhibitor and a number of pathogenic bacteria and fungi, was achieved in two steps from 1-acetylaminomethyl-5,7-diethoxy-8-hydroxy-6-methylisoquinoline (14). The related compounds (8~11) were also synthesized, and the antimicrobial activities of 1 and its nine related compounds (5~13) were investigated.
Published online: 14th February, 2006
■ Synthesis of 2’-O-Methyl-5-alkynyl and alkenyl Substituted Uridine Derivatives to Screen for Inhibitors of HCV
Yili Ding,* Jean-Luc Girardet, Zhi Hong, Stephanie Z. Shaw, and Nanhua Yao
*Drug Discovery, Valeant Pharmaceuticals International, Inc., 3300 Hyland Avenue, Costa Mesa, CA 92626, U.S.A.
Abstract
Using Sonogashira and Heck coupling reactions, a series of 5-alkynyl and 5-alkenyl substituted 2’-O-methyluridine derivatives were synthesized in high yields. These compounds were used to screen for inhibitors of HCV, however none of them showed significant HCV inhibitory activity under 300 μM.
Published online: 21st February, 2006
■ 7-(Imidazolidin-1-ylmethyl)quinolin-8-ol: An Unexpected Product from a Mannich-Type Reaction in Basic Medium
Augusto Rivera,* Jaime Ríos-Motta, and Miguel Angel Navarro
*Departamento de Química, Universidad Nacional de Colombia, Ciudad Universitaria, Carrera 30 # 45-03, Bogotá, Colombia
Abstract
7-(Imidazolidin-1-ylmethyl)quinoline-8-ol, an N-substituted imidazolidine, was synthesized in a one-step reaction between 1,3,6,8-tetraazatricyclo[4.4.1.1]dodecane (TATD) and 8-hydroxyquinoline. Obtaining this substance enhanced the scope of possibilities in the synthesis of unsymmetrically N,N-disubstituted imidazolidines. 1H-NMR spectral studies revealed that this type of substance does not undergo ring-chain tautomerism.
Published online: 14th February, 2006
■ Unexpected 7-Methylation of Oxindoles
Balázs Volk,* Rita Kapiller-Dezsöfi, and Gyula Simig
*Chemical Research Deivision, EGIS Pharmaceuticals Ltd., P.O.Box 100, H-1475 Budapest, Hungary
Abstract
A unique, regioselective 7-methylation reaction has been discovered during the reductive 3-alkylation of isatin with i-BuOH at 230 °C, in the presence of Raney nickel, under hydrogen atmosphere. Based on this observation, a synthetic method has been elaborated for the preparation of 3-alkyl-7-methyloxindoles.
Published online: 21st February, 2006
■ High-yielding Microwave Assisted Synthesis of Quinoline and Dihydroquinoline Derivatives under Solvent-free Conditions
D. Subhas Bose* and Racherla Kishore Kumar
*Organic Chemistry Division III, Fine Chemicals Laboratory, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
Abstract
A mild and efficient solvent-free method has been developed by two different approaches for the synthesis of quinoline and dihydroquinoline derivatives: (i) one-pot reaction of anilines with alkyl vinyl ketones (Skraup reaction) (ii) between various acetophenones and 2-aminoacetophenone (Friedländer reaction) using stable and effective heterogeneous catalyst potassium dodecatangestocobaltate (25 mol %) (PDTC) under microwave irradiation in high yields.
Published online: 28th February, 2006
■ Pyrimidine Chemistry in Crop Protection
Clemens Lamberth
*Chemistry, Crop Protection Research, Syngenta AG, Schwarzwaldallee 215, CH-4002 Basel, Switzerland
Abstract
This review aims to give an overview of the significance of pyrimidine derivatives in crop protection. The main herbicidally, fungicidally and insecticidally active pyrimidine classes are presented, together with their synthetic routes, their modes of action and their biological efficacies. Quinazolines and other bicyclic pyrimidine derivatives are also covered.