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. 8, 2006
Published online: 27th June, 2006
■ TCT (2,4,6-Trichloro-1,3,5-triazine) Promoted Single-Step Syntheis of 4,6-Diarylpyrimidin-2(1H)-ones under Microwave Irradiation
Ahmad R. Khosropour,* Iraj Mohammadpoor-Baltork,* Mohammad M. Khodaei, and Mahbubeh Jokar
*Department of Chemistry, Faculty of Science, Isfahan University, Isfahan 81746-73441, Iran
Abstract
An efficient single-step procedure for the synthesis of 4,6-diarylpyrimidin-2(1H)-ones promoted by Zn(OTf)2-TCT or Bi(OTf)3-TCT under solvent-free microwave irradiation conditions has been developed.
Published online: 23rd June, 2006
■ A Facile and Convenient Synthesis of 1H-Isoindole-1,3(2H)-diones
Farzad Nikpour,* Samira Kazemi, and Davood Sheikh
*Department of Chemistry, Faculty of Sciences, University of Kurdistan, Sanandaj, Pasdaran Bivd., P.O.Box 66135-416, Iran
Abstract
A facile synthesis of 1H-isoindole-1,3(2H)-diones (3a-h) has been developed by the reaction of the corresponding anhydrides (1a-h) with potassium cyanate (4a) or sodium thiocyanate (4b). The reactions were carried out in neutral media under reflux or under microwave irradiation without use of catalyst. Good to excellent yields of the products were obtained in high purity with very simple work-up.
Published online: 23rd June, 2006
■ The Ideal Synthetic Method Aimed at the Leads for an α2-Blocker, an Inhibitor of Blood Platelet Aggregation, and an Anti-osteoporosis Agent
Masanori Somei,* Takako Iwaki, Fumio Yamada, Yoshio Tanaka, Koki Shigenobu, Katsuo Koike, Nobuo Suzuki, and Atsuhiko Hattori
*Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
Abstract
According to the definition of the ideal synthetic method, an example aimed at the leads for an α2-blocker, an inhibitor of platelet aggregation, and an anti-osteoporosis agent is established starting from tryptamine. The originality rate, the intellectual property, and the application potential factors of the method are 71, 54, and 100, respectively. The method employs only conventional reagents and reaction conditions without using any protecting groups.
Published online: 8th June, 2006
■ Preferred Conformations of Diastereomeric N-Acyl-1-naphthylalanylprolinamides and Related Dipeptides and Their Fluorescence Quenching by Chiral Amines
Hiroki Kurosawa, Kana Bakoshi, Shozo Ichikawa, 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
Enantioselective fluorescence quenching was observed in the quenching processes of the 1-naphthylalanyl-(S)-phenylglycinamide-derived diastereomers by enantiomeric pyrrolidine-2-methanols in 1,4-dioxane at room temperature, whereas the (S)-prolinamide-derived ones exhibited only a much weaker enantioselective emission quenching under the same conditions. These findings were explained on the basis of substituent and conformational effects on the stability of a singlet exciplex formed between given diastereomer and chiral amine.
Published online: 27th June, 2006
■ Sulfur-Mediated Synthesis of Substituted Tetrahydrofurans: Application to the Synthesis of Goniofufurone
Roberto Fernández de la Pradilla,* Jorge Fernández, Alma Viso, Javier Fernández, and Antonio Gómez
*Sintesis, Instituto de Química Orgánica, C. S. I. C., Juan de la Cierva, 3, 28006 Madrid, Spain
Abstract
An efficient strategy for the synthesis of densely functionalized 2,5-trans-disubstituted-tetrahydrofurans (4), from sulfinyldienols is described. Further transformations of this substrate have resulted in a new synthesis of goniofufurone (1) by means of silylated lactone (11), also readily available from D-xylose.
Published online: 1st June, 2006
■ Synthesis and Characterization of 1,3,4-Oxadiazoles Triazolopyridinone and Carbazole as the Potential Bluish-Green Electroluminescent Materials for the Single Layer Device
Hung-Te Chang, Kuo-Chen Chiang, Fung Fuh Wong,* and Mou-Yung Yeh*
*Sustainable Environment Research Center, National Cheng Kung University, No. 500, Sec. 3, An-ming Rod., Tainan City, 709, Taiwan, R.O.C.
Abstract
1,3,4-Oxadiazoles carrying triazolopyridinone and carbazolewere synthesized and characterized for the electroluminescent materials in single layer devices. Carbazole and triazolopyridinone were introduced into 2,5-centers of 1,3,4-oxadiazole core to assist the control of fundamental photolytic process due to their electron-donating nature, excellent photo-conductivity, and flexible structure properties. Study from spectrometry and cyclic voltammetry revealed that the 1,3,4-oxadiazole derivatives carrying these two heterocyles are able to be used as the potential bluish-green electroluminescent materials.
Published online: 2nd June, 2006
■ Synthesis and Properties of Some Dihydrotetrazolo[5,1-c][1,2,4]triazines
Jalal A. Zahra, Mustafa M. El-Abadelah,* Bassam A. Abu Thaher, Naser S. El-Abadla, and Roland Boese
*Chemistry Department, Faculty of Science, University of Jordan, Amman 11942, Jordan
Abstract
(5-Mercaptotetrazol-1-yl)acetic acid - nitrile imine acyclic adducts (12a-c) undergo intramolecular cyclocondensation, induced by 1,1’-carbonyldiimidazole (CDI), to afford the respective dihydrotetrazolo[5,1-c][1,2,4]triazines (13a-c). The formation of the latter bicycles implies that 12a-c eject H2O and undergo S→N migration (Smiles rearrangement) with subsequent expulsion of O=C=S. The structures of 13a-c were determined by analytical and spectral data, and confirmed by single crystal X-Ray analysis for 13c.
Published online: 8th June, 2006
■ One-Pot Synthesis of 2-Imino-1,3-selenazolidines by Reaction of Isoselenocyanates with Propargylamine
Mamoru Koketsu,* Tsutomu Sakai, Takashi Kiyokuni, Dinesh R. Garud, Hiromune Ando, and Hideharu Ishihara
*Division of Instrumental Analysis, Life Science Research Center, Gifu University, 1-1 Yanagito, Gifu, Gifu 501-1193, Japan
Abstract
One-pot synthesis of 2-imino-5-methylene-1,3-selenazolidines has been achieved by reactions of alkylisoselenocyanates with propargylamines in high yields. 1H NMR and NOESY experiments were used to explain the selenium coupling with hydrogen of carbon-carbon double bond.
Published online: 8th June, 2006
■ Stilbenoids with One Epoxy Group from Cotylelobium lanceolatum
Tetsuro Ito,* Zulfiqar Ali, Toshiyuki Tanaka, Ken-ichi Nakaya, Jin Murata, Dedy Darnaedi, and Munekazu Iinuma
*Gifu Prefectrual Institute of Health and Environmental Sciences, 1-1 Nakafudogaoka, Kakamigahara, Gifu 504-0838, Japan
Abstract
A phytochemical investigation of an acetone extract of Cotylelobium lanceolatum stem resulted in the isolation of two orange pigments-two stilbene trimer derivatives, cotylelophenols D and E and an artifact derivative, cotylelophenol F. The structure and relative configuration were confirmed by 1D and 2D NMR spectral data. Cotylelophenols D and E are the first examples of stilbene oligomers bearing an epoxy group. The biogenetic relationships between the isolates are also discussed.
Published online: 8th June, 2006
■ Synthesis and Structural Study of Semicarbazone-Containing 1,4-Dihydropyridine
Amaury Álvarez, Margarita Suárez,* Yamila Verdecia, Estael Ochoa, Blavet Barried, Rolando Pérez, Mercedes Díaz, Roberto Martínez-Álvarez, Dolores Molero, Carlos Seoane, Hector Novoa, Norbert M. Blaton, Oswald M. Peetersd, and Nazario Martín*
*Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
A new series of 1,4-dihydropyridines (1,4-DHPs) bearing a semicarbazone moiety on C5 (8a-g) have been synthesized from suitably functionalized 1,4-DHPs (2) and semicarbazide. Compounds (8a-g) did not cyclize to the respective seven member ring though this is a favoured 7-endo-trig process. Geometrical and structural features determined by theoretical, DFT (B3LYP/6-31G*) and experimental (X-Ray diffraction) data, reveal the presence of a low energy stereoisomer, namely (E) s-trans, which is also present in solution according to NOe experiments carried out on compound (8a). These geometrical findings account for the lack of cyclization of compounds (8a-g), and reveal that they meet the structural requirements needed for biological activity as calcium-channel modulators.
Published online: 2nd June, 2006
■ Ionic Liquid in Organic Synthesis: The Pictet-Spengler Reaction
Huey-Min Wang,* Rei-Sheu Hou, Hsin-Yu Huang, and Ling-Ching Chen*
*Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, 100 Shin Chuan 1st Rd., Kaohsiung 80708, Taiwan, R.O.C.
Abstract
We have demonstrated the use of the room temperature ionic liquid, 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF6), as an environmentally benign solvent for the preparation of 2-benzenesulfonyl-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ethyl ester derivatives through Pictet-Spengler reaction using phenyliodine(III) bis(trifluoroacetate) (PIFA) under mild conditions.
Published online: 27th June, 2006
■ Phosphoric Acid-on-Silica Gel: A Green Catalyst for the Synthesis of Symmetrical Bis(indolyl)alkanes
Manas Chakrabarty,* Ratna Mukherjee, Ajanta Mukherji, Shiho Arima, and Yoshihiro Harigaya
*Department of Chemistry, Bose Institute, 93/1, A. P. C. Road, Kolkata-700009, India
Abstract
Orthophosphoric acid, adsorbed on TLC-grade silica gel, has been demonstrated to be an efficient green catalyst for an expeditious and solvent-free one-step synthesis of symmetrical bis(indolyl)alkanes from the reaction of indoles with aryl aldehydes at 60-70 °C.
Published online: 27th June, 2006
■ A Simple KHSO4 Promoted Synthesis of 2-Arylsubstituted Benzimidazoles by Oxidative Condensation of Aldehydes with o-Phenylenediamine
Huiqiang Ma, Yulu Wang, and Jinye Wang*
*College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, 453007, Henan, China
Abstract
KHSO4 is used to promote the oxidative condensation of o-phenylenediamine with aldehydes in DMF and afford corresponding 2-substituted benzimidazoles efficiently. Simple and convenient procedure, use of inexpensive promoter, easy purification and shorter reaction time are the advantageous features of this method.
Published online: 27th June, 2006
■ Indium-Mediated Reductive Cyclization of 2-Nitrochalcones to Quinolines
Rongbi Han, Shen Chen, Sun Jung Lee, Fang Qi, Xue Wu, and Byeong Hyo Kim*
*Department of Chemistry, Kwangwoon University, 447-1, Wolgye-Dong Nowon-ku, Seoul, 139-701, Korea
Abstract
The reductive cyclization of 2-nitrochalcones using indium in an aqueous alcohol solution containing ammonium chloride produced the corresponding quinolines in reasonable yields.
Published online: 2nd June, 2006
■ Hetero-Diels-Alder Reaction of Ethyl 2-Nitrosoacrylate and Cyclohexadienes, and Bromine Induced Diene Isomerization
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
Bicyclic 8a-methoxy-1,2-oxazine (3a) and bicyclic 7-methoxy-1,2-oxazine (3b) were prepared via Hetero-Diels-Alder reaction between 1-methoxy-1,4-cyclohexadiene (2a) and ethyl 2-nitrosoacrylate generated in situ from ethyl bromopyruvate oxime (1). The formation of 3b was ascribed to bromine, released from 1, which induced transformation of 2a to 1-methoxy-1,3-cyclohexadiene (2b). 3b could be easily transformed to oxazinone (3c) in CHCl3, or other organic solvents in the presence of a trace amount of acid.
Published online: 1st June, 2006
■ Two New Indoloquinazoline Alkaloids from the Unripe Fruits of Evodia rutaecarpa
Jie Teng and Xiu-Wei Yang*
*The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China
Abstract
Two new indoloquinazoline alkaloids, wuzhuyurutine A and wuzhuyurutine B, together with three known indoloquinazoline alkaloids, were isolated from the unripe fruits of Evodia rutaecarpa (Juss.) Benth. (Rutaceae). Their structures were elucidated by the analysis of their NMR, MS, IR, UV spectra.
Published online: 23rd June, 2006
■ An Acylated Cyanidin 3-Rutinoside-7-glucoside with p-Hydroxybenzoic Acid from the Red-Purple Flowers of Campanula medium
Kenjiro Toki, Norio Saito, Megumi Ito, Atsushi Shigihara, and Toshio Honda
*Laboratory of Floriculture, Minami-Kyushu University, 11609 Takanabe, Koyu-gun, Miyazaki 884-0003, Japan
Abstract
A new acylated anthocyanin was isolated from the red-purple flowers of Campanula medium as a major pigment together with a known anthocyanin. The new pigment was determined to be cyanidin 3-O-[6-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-7-O-{4-[6-O-(4-(6-O-(p-hydroxybenzoyl)-β-D-glucopyranosyl)oxybenzoyl)-β-D-glucopyranosyloxybenzoyl]-β-D-glucopyranoside} based on spectroscopic analyses. The known pigment was also identified to be rubrocampanin, pelargonidin 3-rutinoside-7-(p-hydroxybenzoylglucopyranosyl-p-hydroxybenzoylglucopyranosyl-p-hydroxybenzoylglucopyranoside).
Published online: 8th June, 2006
■ A Computational Study on Stabilities of Dihydropterins
Shizuaki Murata* and Sudhir S. Landge
*Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
Abstract
Molecular orbital calculation indicated that the potential energy of 7,8-dihydrobiopterin was at least 30 kJ/mol lower than those of other dihydrobiopterin isomers. The instability and reactivity of quinonoid dihydrobiopterin and 5,6-dihydrobiopterin in aqueous solutions were explained not only by energy values but also by orbital figures of LUMOs.
Published online: 8th June, 2006
■ Synthesis of Benzo[2,1-b:3,4-b’]dithiophene-4,5-dione Derivatives
Kazuhiro Kobayashi,* Toshikazu Ogata, Daizo Nakamura, Osamu Morikawa, and Hisatoshi Konishi
*Department of Materials Science, Faculty of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan
Abstract
The 1-trimethylsilylimidazole-mediated thiophene ring formation from 6-acylbenzo[b]thiophene-4,5-diones (3), which were prepared utilizing photoacylation of benzo[b]thiophene-4,5-dione (1) with aliphatic aldehydes, and ethyl mercaptoacetate, followed by acid hydrolysis and oxidation with cerium(IV) ammonium nitrate (CAN), led to one-pot formation of the 3-substituted ethyl 4,5-dioxo-4,5-dihydrobenzo[2,1-b:3,4-b‘]dithiophene-2-carboxylates (4) in satisfactory yields.
Published online: 20th June, 2006
■ Synthesis of Substituted Aminoquinolines as Useful Intermediates for Preparation of Aromatic N-Tricyclic Systems
Antonio Carta,* Michele Palomba, and Paola Corona
*Department of Medicinal and Toxicological Chemistry, University of Sassari, Via Muroni 23, 07100 Sassari, Italy
Abstract
An effective approach for the synthesis of new substituted mono and diaminoquinolines is described. Two known quinolines 7,8-dichloro-6-nitroquinoline (1) and 7,8-dichloro-6-nitrohydroquinolin-4-one (9) were used as key intermediates.
Published online: 27th June, 2006
■ 1,2,4-Triazolo[1,5-a][1,3,5]triazines (5-Azapurines): Synthesis and Biological Activity
Anton V. Dolzhenko, Anna V. Dolzhenko, and Wai-Keung Chui*
*Department of Pharmacy, Faculty of Science, National University of Singapore, 18 Science Drive 4, Singapore 117543, Singapore
Abstract
The present review gives an account of the various synthetic routes to the 5-aza-analogue of purine-1,2,4-triazolo[1,5-a][1,3,5]triazine nucleus and polyfused systems bearing this heterocyclic core. Data concerning biological activity of the compounds with 1,2,4-triazolo[1,5-a][1,3,5]triazine skeleton are also discussed.