Regular Issue

Vol. 75, No. 8, 2008

16 data found. 1 - 16 listed
Review | Regular issue | Vol 75, No. 8, 2008, pp. 1849 - 1905
Published online: 29th February, 2008
DOI: 10.3987/REV-07-625
Enamines as Precursors to Polyfunctional Heteroaromatic Compounds; a Decade of Development

Sayed M. Riyadh,* Ismail A. Abdelhamid, Hamad M. Al-Matar, Noha M. Hilmy, and Mohamed H. Elnagdi

*Department of Chemistry, Faculty of Science, Cairo University, Giza-12613- Egypt


Recent synthesis and utilization of enamines as precursors for heterocyclic and carbocyclic compounds are reviewed. Two general synthetic routes for preparation of enamines based on condensation and addition reactions. Enamines and azaenamines can be used as building blocks for carbocyclic, five- and six-membered heterocyclic as well as fused heterocyclic compounds.

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Communication | Regular issue | Vol 75, No. 8, 2008, pp. 1907 - 1911
Published online: 17th April, 2008
DOI: 10.3987/COM-08-11384
A Facile One-Pot Synthesis of Benzimidazoles from 2-Nitroanilines by Reductive Cyclization

Zheng Liu, Haihong Li, Qingjie Zhao, and Jingshan Shen

*Shanghai Institute of Materia Medica, The Chinese Academy of Sciences, 319 Yue-Yang Raod, Shanghai 200031, China


A facile one-pot process to prepare benzimidazole derivatives is described. Reductive cyclization of a serial of 2-nitroanilines with orthoesters in the presence of Pd/C in methanol at room temperature, which is promoted by a catalytic amount of acetic acid, affords the corresponding benzimidazole derivatives in high yields.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1913 - 1929
Published online: 1st April, 2008
DOI: 10.3987/COM-08-11326
Solvent-Free Microwave Synthesis of 3-(4-Benzo[b]thiophene-2-carbonyl)-1-piperazinyl-1-benzo[b]thiophen-2-yl-1-propanones. New Hetero Bis-Ligands with Potential 5-HT1A Serotonergic Activity

Hernán Pessoa-Mahana,* Johann Kosche C., Nadia Ron H., Gonzalo Recabarren-Gajardo, Claudio Saitz B., Ramiro Araya-Maturana, and C. David Pessoa-Mahana

*Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Casilla 233, Santiago 1, Chile


A novel series of 2-benzothiophenealkylpiperazine derivatives 11(a-d) with potential affinity at 5-HT1A serotonine receptors have been synthesized via solvent-free, microwave-promoted Michael addition of benzo[b]thiophene piperazine derivatives 6(a-c) to substituted benzo[b]thiophen-2-yl propenones 10(b,c).

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1931 - 1942
Published online: 1st April, 2008
DOI: 10.3987/COM-08-11337
Selenomaltol — Synthesis, Spectroscopy and Theoretical Calculations

Waldemar Tejchman,* Krzysztof Zborowski, Wieslaw Lasocha, and Leonard M. Proniewicz

*Department of Chemistry, Pedagogical University, Podchorazych St. 2, PL-30084 Kraków, Poland


Synthesis and structure of the seleno derivative of maltol (selenomaltol) is described. Structural and energetical properties of possible selenomaltol structures have been calculated at the B1LYP/6-311++G(d,p) level. The lowest energies are always predicted for the keto-enol tautomer. To verify obtained results several standard experimental methods, namely: elemental analysis, mass spectrometry, infrared and NMR spectroscopies and X-ray crystallography have been used. Investigation of IR and NMR spectra clearly indicate that the oxygen atom of exocyclic keto group on maltol was replaced by selenium. Experimental crystallographic results support this conclusion.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1943 - 1952
Published online: 8th April, 2008
DOI: 10.3987/COM-08-11346
Synthesis of Acridine Analogues as Intercalating Crosslinkers and Evaluation of Their Potential Anticancer Properties

Toshinori Higashi, Maki Sakamoto, and Masataka Mochizuki*

*Faculty of Pharmacy, Keio University, 1-5-30, Shiba-koen, Minato-ku, Tokyo 105-8512, Japan


We synthesized 4,5-bis(halomethyl)acridines, which contain an acridine skeleton for DNA intercalation and two halomethyl groups for DNA crosslinking. 4,5-Bis(bromomethyl)acridine and 4,5-bis(chloromethyl)acridine intercalated in DNA and mediated interstrand DNA crosslinking. Both compounds were cytotoxic to CCRF-HSB-2 cells, a human T cell leukemia cell line. Molecular modeling of 4,5-bis(bromomethyl)acridine intercalated in 5’-GC-3’ base pairs of DNA indicated that the bromomethyl group, which mediates alkylation, is in close proximity to N7 of guanine.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1953 - 1961
Published online: 11th April, 2008
DOI: 10.3987/COM-08-11365
Synthesis of New Thiazolo[3,2-a]pyrimidin-5-one Derivatives in Reaction of 3-Allyl-2-thiouracils Cyclization

Renata Studzinska, Marcin Wróblewski, and Marcin Draminski*

*Department of General Chemistry, Nicolaus Copernicus University in Torun, Collegium Medicum in Bydgoszcz, ul. Debowa 3, 85-626 Bydgoszcz, Poland


The series of thiazolo[3,2-a]pyrimidin-5-one derivatives in cyclization reaction of 3-allyl-2-thiouracil derivatives with iodine monochloride, and then hydrogen iodide elimination from intermediate reaction product has been obtained. On the basis of the studies of reaction kinetics, the elimination reaction mechanism has been proposed. Moreover, the influence of substituent on the reaction elimination rate has been investigated.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1963 - 1970
Published online: 21st March, 2008
DOI: 10.3987/COM-08-11366
Investigation of the Acid-Mediated Cyclisation of Amide Acetal for the Synthesis of Benzazepinone

Wong Phakhodee, Poolsak Sahakitpichan, Songpon Deechongkit, and Somsak Ruchirawat*

*Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, Vipavadee-Rangsit Road, Laksi, Bangkok 10210, Thailand


On treatment with acids, the open-chained amide acetals (1) gave the 7,7 membered ring fused benzazepinones (4) via the bis-cyclisation.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1971 - 1981
Published online: 8th April, 2008
DOI: 10.3987/COM-08-11370
Halolactonization of γ-Acetylenic Acids: Synthesis of Novel Spiroisoindole Halobutyrolactones

Mohamed M. Rammah, Mohamed Othman,* Moncef Msaddek, and Mohamed B. Rammah

*URCOM, Faculty of Sciences and Techniques, University of Le Havre, 25 Rue Philippe Lebon, BP 540, F-76058 Le Havre Cedex, France


Acetylenic carboxylic acids are cyclized to spirohalo butyrolactones, in the presence of NBS or NIS and K2CO3. The corresponding 5(E)-haloalkylidene-spirobutyrolactones were isolated in high yields, and this process constitutes an easy and efficient route to analogous structures of natural products of biological interest.

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Paper | Regular issue | Vol 75, No. 8, 2008, pp. 1983 - 1995
Published online: 17th April, 2008
DOI: 10.3987/COM-08-11385
Bioactive Constituents from Chinese Natural Medicines. XXXI. Hepatoprotective Principles from Sinocrassula indica: Structures of Sinocrassosides A8, A9, A10, A11, and A12

Kiyofumi Ninomiya, Toshio Morikawa, Haihui Xie, Hisashi Matsuda, and Masayuki Yoshikawa*

*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan


The methanolic extract from the whole plant of Sinocrassula indica (Crassulaceae) was found to show hepatoprotective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, five new acylated flavonol glycosides, sinocrassosides A8 (1), A9 (2), A10 (3), A11 (4), and A12 (5), were isolated together with 25 compounds. The structures of 1-5 were elucidated on the basis of chemical and physicochemical evidence. Among the isolated compounds, sinocrassosides A1 (6), A2 (7), and B2 (14) were found to show potent hepatoprotective effect.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 1997 - 2003
Published online: 8th April, 2008
DOI: 10.3987/COM-08-11331
Effects of Aromatic Substituents of Electrochemically Generated Hypervalent Iodine Oxidant on Oxidation Reactions

Yoshiharu Amano and Shigeru Nishiyama*

*Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi, Kohoku-ku Yokohama 223-8522, Japan


Phenolic oxidation of 4-hydroxyphenylpropionic acid (5) with electrochemically generated hypervalent iodine oxidant, was performed using a variety of iodobenzene derivatives. Iodobenzene derivatives carrying electron-deficient aromatic moieties showed oxidant activity comparable to that of bis(2,2,2-trifluoroethoxy)phenyliodine(III) 1, and better than those carrying electron-donating groups with the exception of a methyl group. In our electrochemical procedure, the oxidant from 1-iodo-4-nitrobenzene was obtained as a stable solid, while other oxidants that did not precipitate from the reaction mixture, were used in situ. Conversion of the methoxyamide 7 into the corresponding azaspiro derivative 3 was also performed by the oxidants carrying aromkatic substitutions.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2005 - 2012
Published online: 28th March, 2008
DOI: 10.3987/COM-08-11355
Synthesis of Novel Pyrazolo[5,1-b][1,3]benzothiazoles: A New Pericyclic Pathway

Betül Tekiner-Gulbas, László Filák, Gyöngyvér Ágnes Vaskó, Orsolya Egyed, Ismail Yalçin, Esin Aki-Sener, Zuzsanna Riedl, and György Hajós*

*Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1025 Budpest, Pusztaszeri út 59, P.O. Box 17, Hungary


2-Benzylbenzothiazoles were easily N-aminated by tosyl hydroxylamine, and the obtained N-amino salts were reacted with ethyl orthoformate to give new derivatives of the pyrazolo[5,1-b][1,3]benzothiazole ring system. Mechanistic considerations suggest that the ring closure reaction proceeds via deprotonation of the N-amino salt followed by electrocyclization to provide the tricyclic ring system. The procedure opens an easy access to variously substituted derivatives of the target ring system.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2013 - 2021
Published online: 1st April, 2008
DOI: 10.3987/COM-08-11357
New β-Tricarbonyl Compounds: Synthesis, Reactions with Urea and Some Thioureas

Mustafa Saçmaci,* Abdulrezzak Alkan, Serife Saçmaci, Emin Saripinar, and Ertan Sahin

*Department of Chemistry, Faculty of Arts and Sciences, Bozok University, Yozgat 66200, Turkey


2,3-Dihydro-4-(4-methoxybenzoyl)-5-(4-methoxyphenyl)furan-2,3-dione 1 reacted with some alkyl carbamates (3a-b) via p,p’-dimethoxy- dibenzoylketene intermediate 2 giving new β-tricarbonyl compounds (4a-b). Then, these compounds were converted into 1,3-oxazine-2,4(3H)-dione 7 with urea and 2-thioxo-2,3-dihydropyrimidin-4(1H)-ones (6a-c) with some thiourea derivatives, respectively. Pyrimidin-4-ones (6a-c) and oxazine 7 were obtained in good yields. The structures and characterizations of new synthesized compounds were established by the 1H and 13C NMR, IR, UV-VIS spectroscopic data, elemental analysis, and X-ray diffraction method.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2023 - 2028
Published online: 8th April, 2008
DOI: 10.3987/COM-08-11358
Aplysinopsin Dimers from a Stony Coral. Tubastraea aurea

Tetsuo Iwagawa,* Miho Miyazaki, Yukiko Yokogawa, Hiroaki Okamura, Munehiro Nakatani, Matsumi Doe, Yoshiki Morimoto, and Kaoru Takemura

*Department of Chemistry and Bioscience, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan


Five novel bis(indole) alkaloids, which were composed of two molecules of aplysinopsin have been isolated from a stony coral, Tubastraea aurea. Their structures were elucidated on the basis of spectroscopic methods.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2029 - 2034
Published online: 11th April, 2008
DOI: 10.3987/COM-08-11363
Chemical Constituents of Ligularia franchetiana Collected in Yunnan Province of China

Motoo Tori,* Yui Tanio, Yasuko Okamoto, Yoshinori Saito, Xun Gong,* Chiaki Kuroda,* and Ryo Hanai*

*Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamabouji, Yamashiro-machi, Tokushima, 770-8514, Japan


Two new ketones, franchetianones A and B, were isolated from the root of Ligularia franchetiana collected in Yunnan province of China and their structures determined based on the spectroscopic analyses.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2035 - 2042
Published online: 28th March, 2008
DOI: 10.3987/COM-08-11371
2-Pyrazolin-5-ones Bearing a Basic Dialkylaminoalkyl Substituent at the N1-Position: Preparation and NMR Spectroscopic Investigations

Barbara M. T. Wolf, Gernot A. Eller,* and Wolfgang Holzer*

*Department of Drug and Natural Product Synthesis, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria


2n-5-ones (= tautomers to 5-hydroxypyrazols) bearing dialkylaminoyalkyl substituents at the ring nitrogen atom N-1 are prepared from the corresponding hydrazines and beta-ketoesters. Detailed NMR spectroscopic investigations (1H, 13C, 15N) with the obtained compounds are undertaken and the tautomerism of such pyrazolones in solution is discussed.

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Note | Regular issue | Vol 75, No. 8, 2008, pp. 2043 - 2061
Published online: 14th April, 2008
DOI: 10.3987/COM-08-11377
Conformationally Constrained Adamantaneoxazolines of Pharmacological Interest

Ioannis Papanastasiou, George B. Foscolos,* Andrew Tsotinis, Judit Oláh, Judit Ovádi, S. Radhika Prathalingam, and John Kelly

*Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis-Zografou, Athens GR-15771, Greece


New conformationally constrained adamantane 2-oxazoline building blocks 1-4 were synthesized and their antimicrotubule and antitrypanosomal potency was investigated. Although most of the new compounds affect tubulin polymerization, this does not make a major contribution to trypanocidal activity.

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16 data found. 1 - 16 listed