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. 6, 2006
Published online: 21st April, 2006
■ An Efficient Synthesis of (±)-Myxopyronin B via Versatile Pyridone Intermediates
Ricardo Lira, Konstantinos A. Agrios, Thomas Doundoulakis, Klaus B. Simonsen, Stephen E. Webber, and Alan X. Xiang*
*Department of Medicinal Chemistry, Anadys Pharmaceuticals, inc., 3115 Merryfield Row, San Diego, CA 92121, U.S.A.
Abstract
(±)-Myxopyronin B was synthesized via the interconversions of pyrone and pyridone moieties. The key steps involve a BuLi-catalyzed aldol condensation and the conversion of an advanced N-methyl pyridone ester intermediate to the corresponding pyrone acid under basic hydrolysis.
Published online: 28th April, 2006
■ Synthesis and Fluorescence of 6-(4-Dimethylaminophenyl)- and 6-[2-(4-N,N-Disubstituted Aminophenyl)vinyl]-4-methylthio-2-oxo-2H-pyran-3-carbonitriles in Solution and in the Solid States
Naoko Mizuyama, Yuka Murakami, Junko Nagaoka, Shinya Kohra, Kazuo Ueda, Kyoko Hiraoka, Yasuhiro Shigemitsu, and Yoshinori Tominaga*
*Faculty of Enviromental Studies of Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan
Abstract
Fluorescent dyes, 6-(4-dimethylaminophenyl)-4-methylthio- and 6-[2-(4-N,N- disubstituted aminophenyl)vinyl]-4-methylthio-2-oxo-2H-pyran-3-carbonitriles (3a-d) were synthesized by the reaction of 4-dimethylaminoacetophenone (1a) and 4-aminobenzalacetone derivatives (1b-d) with ketene dithioacetal (2) in the presence of sodium hydroxide in dimethyl- sulfoxide at room temperature. These 2-pyrone derivatives (3a-d) showed orange and red fluoresecence (Fmax: 607, 699, 705, 645 nm) in dichloromethane solution. The preparation and fluorescence 4-amino-2H-pyrone derivatives is also described.
Published online: 2nd May, 2006
■ Synthetic Utilization of Polynitroaromatic Compounds. 4. Synthesis of Nitro-free 4,6-Disubstituted-3-aminobenzothiophene Derivatives Based on 2,4,6-Trinitrobenzamide
Sergei G. Zlotin,* Pavel G. Kislitsin, Fedor A. Kucherov, and Andrei A. Gakh*
*Oak Ridge National Laboratory, Oak Ridge, TN 37831-6242, USA
Abstract
A convenient synthesis of nitro-free 4,6-disubstituted 3 aminobenzothiophenes, their S-oxides and S,S-dioxides based on the available 2,4,6-trinitrobenzamide has been developed. The synthesis entails stepwise nucleophilic substitution of all nitro groups in the starting compound by S-, N-, and O-nucleophiles followed by Thorpe-Ziegler cyclization.
Published online: 11th April, 2006
■ Facile Synthesis of 2-Arylpyrroles from 4-Oxo-butanoic Acids and Their Use in the Preparation of Bis(pyrrolyl)methanes
David J. Jones and Vernon C. Gibson*
*Imperial College London, Exhibition Road, London, SW7 2AZ, U.K.
Abstract
A range of 3-aroyl-propionic acids have been cyclised to unsaturated lactones which, upon reduction using DIBAL-H and reaction with an ammonia source, gave 2-arylpyrroles (Ar = Ph, 1-naphthyl, o-phenoxyphenyl and 4-methyl-2-methylsulfanylphenyl) in excellent yields. Reaction of 2,6-disubstituted aroylpropanals (Ar = 2,4,6-Me3C6H2, anthracenyl and 2-Me-naphthalen-1-yl) with an ammonia source failed to generate pyrroles. The arylpyrroles react readily with ketones or aldehydes in ethanol or under eutectic mix melt conditions to give bis-(pyrrolyl)methanes in excellent isolated yields.
Published online: 18th April, 2006
■ Bioactive Saponins and Glycosides. XXVI. New Triterpene Saponins, Theasaponins E10, E11, E12, E13, and G2, from the Seeds of Tea Plant (Camellia sinensis)
Toshio Morikawa, Hisashi Matsuda, Ning Li, Seikou Nakamura, Xian Li, and Masayuki Yoshikawa*
*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan
Abstract
New triterpene saponins, theasaponins E10, E11, E12, E13, and G2, were isolated from the saponin fraction of the seeds of Camellia sinesis. Their stereostructures were elucidated on the basis of chemical and physicochemical evidence.
Published online: 11th April, 2006
■ Expeditious Synthesis of 2-Aryl Substituted Imidazolines and Imidazoles
Sylvia Lauwagie, Régis Millet, Jean Pommery, Patrick Depreux,* and Jean-Pierre Hénichart
*Institut de Chimie Pharmaceutique Albert Lespagnol, Université de Lille 2, EA2692, 3 rue du Professeur Laguesse, BP 83, 59006 Lille, France
Abstract
A versatile and efficient method for the synthesis of 2-aryl substituted imidazolines and imidazoles bearing a carboxylate group on C-4 is reported. Three different synthetic pathways were explored, compared and optimized. The selected procedure involves condensation of methyl 2,3-diaminopropionate with different imino ethers. The ring closure, monitored by LC-MS analysis, was facilitated by heating at reflux in ethanol leading to increase the rate of cyclization.
Published online: 18th April, 2006
■ Heterocycles [h]Fused onto 4-Oxoquinolines. Part I. Synthesis of 6-Oxo-6,9-dihydro[1,2,5]oxadiazolo[3,4-h]quinoline-7-carboxylic Acid N-Oxide
Yusuf M. Al-Hiari, Monther A. Khanfar, Ali M. Qaisi, Mohammad Y. Abu Shuheil, Mustafa M. El-Abadelah,* and Roland Boese
*Chemistry Department, Faculty of Science, University of Jordan, Amman, Jordan
Abstract
Ethyl 9-cyclopropyl-4-fluoro-6-oxo-6,9-dihydro[1,2,5]oxadiazolo[3,4-h]quinoline-7-carboxylate N(3)-oxide (3) is synthesized via pyrolysis of the 7-azido-8-nitroquinoline-3-carboxylate precursor (6). Acid-catalyzed hydrolysis of the product (3) afforded the corresponding carboxylic acid (4), of which structures are confirmed by spectroscopic means including X-Ray measurements.
Published online: 11th April, 2006
■ Concise Synthesis of 3-Arylpiperidines
Meng-Yang Chang,* Ru-Ting Hsu, Hua-Ping Chen, and Pei-Jung Lin
*Department of Applied Chemistry, National University of Kaohsiung, Kaohsiung 811, Taiwan, R.O.C.
Abstract
We present an easy and straightforward synthesis of 3-arylpiperidines by Grignard addition of piperidin-3-one with different arylmagnesium bromide reagents and acidic dehydroxylation of the resulting tertiary alcohol with the combination of triethylsilane and boron trifluoride etherate. This facile strategy was further used to synthesize preclamol. A highly regioselective dehydration of 3-arylpiperidin-3-ol with boron trifluoride etherate was investigated for preparing 3-aryl-1,4,5,6-tetrahydropyridine skeleton. A novel selenium dioxide mediated dihydroperoxidation of 3-aryl-1,4,5,6-tetrahydropyridine was also examined.
Published online: 25th April, 2006
■ An Convenient Method for the Synthesis of 7,8-Dimethoxy-3-hydroxyquinolin-2(1H)-one and Its Tautomer Conformation Study
Jian Song, Yongcheng Lin,* Yau Shan Szeto, and Wing Lai Chan*
*School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China
Abstract
3-Hydroxyquinolin-2(1H)-one (1) was synthesized successfully from readily available 2-nitroveratraldehyde in a three-step reaction. The procedure was based on existing protocol but with slight modification to give a much higher production yield. The tautomer conformation of the quinolinone was studied.
Published online: 25th April, 2006
■ Synthesis of Selenosemicarbazides and 1,2,4-Triazoles
Mamoru Koketsu,* Yusuke Yamamura, and Hideharu Ishihara*
*Division of Instrumental Analysis, Life Science Research Center, Gifu University, Gifu 501-1193, Japan
Abstract
Acyl isoselenocyanates (1) were prepared from KSeCN and acyl chlorides in situ. Reactions of the acyl isoselenocyanates (1) with phenylhydrazine gave 2-phenyl-1,2-dihydro-3H-1,2,4-triazole-3-selones (2) and selenosemicarbazides (3). The obtained selenosemicarbazides (3) were refluxed in the presence of triethylamine in THF and trapped with alkyl halides to obtain the corresponding 3-alkylseleno-1-phenyl-1H-1,2,4-triazoles (5) in moderate yields.
Published online: 4th April, 2006
■ Synthesis and Extraction Properties of New Fused Benzocrown-Heterocycle Ligands for Alkali and Alkaline Earth Metal Cations
Seyed Mohammad Seyedi* and Toktam Pakseresht
*Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, 91775, Iran
Abstract
Heterocyclic compounds (5-9) were synthesized and reacted with 4,5-bis (bromomethyl) benzo-15-crown-5 to afford the fused benzocrown - heterocycle ligands (10-14). The complexing ability of these macrocyclic ligands toward Li+, Na+, K+, Mg2+, Ca2+, Li+/Mg2+ and Li+/K+ was measured by the solvent extraction method. The data show that extractability of the double cations enhances remarkably when compared with the extraction ability of the single cation.
Published online: 18th April, 2006
■ Microwave-promoted Aromatization of 1,3,5-trisubstituted 4,5-Dihydro-1H-pyrazoles by Calcium Hypochlorite under Solvent-free Conditions
Davood Azarifar* and Azadeh Gharshasbi
*Department of Chemistry, School of Science, Bu-Ali Sina University, Hamadan 65174, Iran
Abstract
An efficient microwave-promoted aromatization of 1,3,5-trisubstituted 4,5-dihydro-1H-pyrazoles using calcium hypochlorite [Ca(OCl)2] has been reported. The reaction proceeds very fast to give pyrazoles in good yields on irradiation of a mixture of the dihydropyrazole and Ca(OCl)2 on alumina without using solvent.
Published online: 18th April, 2006
■ Water-tolerant and Reusable Catalyst for the One-pot Synthesis of Dihydropyrimidin-2(1H)-ones under Solvent-free Conditions
D. Subhas Bose,* M. Venu Chary, and Hari Babu Mereyala
*Organic Chemistry Division III, Fine Chemicals Laboratory, Indian Institute of Chemical Technology, Tarnaka, Hyderabad, 500 007, India
Abstract
An efficient and eco-friendly synthesis of 3,4-dihydropyrimidin-2(1H)-ones, has been achieved by a three-component condensation reaction of an aldehyde, β-ketoester and urea, in the presence of K5CoW12O40.3H2O (0.01 equiv. or 1.0 mol %) as catalyst under solvent-free conditions. The catalyst exhibited remarkable reusable activity. The scope of this method is utilized for the synthesis of mitotic kinesin EG5 inhibitor monastrol.
Published online: 2nd May, 2006
■ Regioselective Synthesis of the Novel N4-Substituted Pyrazolo[4,5-e][1,2,4]thiadiazines as Potent HIV-1 NNRTIs
Xinyong Liu,* Niangen Chen, Renzhang Yan, Wenfang Xu, Maria Teresa Molina, and Salvador Vega
*Institute of Medicinal Chemistry, School of Pharmacy, Shandong University, 250012 Jinan, China
Abstract
A new ring system of 7-methylpyrazolo[4,5-e][1,2,4]thiadiazine (5) was synthesized. Starting from 5 a series of novel mono N4-substituted derivatives (6) were prepared regioselectively and evaluated as potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs).
Published online: 2nd May, 2006
■ Palladium-catalyzed Asymmetric Allylic Alkylation Using Chiral Pyridyl-hydrazone Ligands
Takashi Mino,* Yoshiaki Shirae, Toru Yajima, Masami Sakamoto, and Tsutomu Fujita
*Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
Abstract
Palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (5) with a dimethyl malonate-BSA-LiOAc system has been successfully carried out in the presence of chiral pyridyl-hydrazone ligands such as 2c with moderate enantioselectivities (up to 67% ee).
Published online: 11th April, 2006
■ Evoninoate Sesquiterpene Alkaloids from the Stem of Celastrus paniculatus
Yasu Lu, Shilin Yang, Zhongmei Zou, Xiuzhen Luo, Hebin Chen, and Lizhen Xu
*Institute of Medicinal Plant Development, Beijing 100094, China
Abstract
Two novel evoninoate sesquiterpene alkaloids, paniculatine A (4) and paniculatine B (5) with two known, euonymin (2) and wifornine F (3), were isolated from the stem of Celastrus paniculatus. The structures of the new compounds were elucidated by 2D NMR techniques and spectral comparison. The configuration of C-2’ and C-3’ of 2 and 3 was determined for the first time by spectral comparison.
Published online: 21st April, 2006
■ Synthesis and Structural Properties of Cyclophanes Containing Thiophene Rings in the Side-chain
Aldo Taticchi,* Assunta Marrocchi, Lucio Minuti, Selvaggia Landi, and Eszter Gacs-Baitz
*Dipartimento di Chimica, Università degli Studi di Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
Abstract
The synthesis of some cyclophanes bearing in the linear side-chain carbon-carbon triple bonds conjugated with thiophene rings has been reported. Structure analysis of the products based on extensive NMR investigation is presented. UV-Vis absorption spectra and fluorescence spectra have been measured. The analysis of the spectra points out a correlation between the maxima and the structure of the side-chain. The replacement of a benzene ring with a thiophene ring causes a bathochromic shift when the benzene ring close to the paracyclophane moiety is replaced.
Published online: 25th April, 2006
■ New Lignans from Kadsura coccinea and Their Nitric Oxide Inhibitory Activities
Heran Li, Yulin Feng, Zhigang Yang, Zhongmei Zhou, Lizhen Xu, Akihiro Daikonya, Jue Wang, Susumu Kitanaka,* and Shilin Yang*
*Institute of Medicinal Plant Development, Peking Union Medical College & Chinese Academy of Medical Sciences Beijing, P.R. China
Abstract
In vitro anti-allergic screening of medicinal herbal extracts revealed that the chloroform extract of the rhizoma of Kadsura coccinea inhibited nitric oxide (NO) production in a lipopolysaccharide (LPS) and recombinant mouse interferon-γ (IFN-γ) activated murine macrophage like cell line, RAW264.7. Further fractionation of the chloroform extract led to the isolation of two new lignans kadsuralignans D (1) and E (2) with other two known dibenzocyclooctadiene lignans kadsulignan N (3) and neokadsuranin (4).
Published online: 25th April, 2006
■ Synthesis of 1,3-Selenazetidines and 4H-1,3,5-Oxadiazines Using Acyl Isoselenocyanates
Mamoru Koketsu,* Yusuke Yamamura, Hiromune Ando, and Hideharu Ishihara*
*aDivision of Instrumental Analysis, Life Science Research Center, Gifu University, Gifu 501-1193, Japan
Abstract
Reactions of acyl isoselenocyanates with carbodiimides afforded 1,3-selenazetidines as major product and 4-selnoxo-3,4-dihydro-2H-1,3,5- oxadiazine as minor product, respectively.