Regular Issue

Vol. 68, No. 5, 2006

15 data found. 1 - 15 listed
Communication | Regular issue | Vol 68, No. 5, 2006, pp. 879 - 884
Published online: 28th March, 2006
DOI: 10.3987/COM-06-10681
Synthesis and Reactivity of Dibenz[d,g]azecin-14(5H)-ones

Patrick Mohr, Jochen Lehmann, and Michael Decker*

*Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University of Jena, Philosophenweg 14, D-07743 Jena, Germany


Ring cleavage of the central C,N-bond in quaternary dibenz[a,h]quinolizinium salts with sodium hydride in DMSO yielded novel dibenz[d,g]azecin-14(5H)-ones, which produce cyclic carbinolamine derivatives in an acidified medium by transannular interaction. Investigations into the optimization of the NaH/DMSO reaction as ring cleaving reaction were performed. The ketone moiety of the azecinones is remarkably stable towards different reductive agents most probably due to steric hindrance, because also the quaternary ammonium salts which are unable to recyclize to carbinolammonium salts could not be reduced either. The compounds were screened for their affinity to hD1-, hD2- and hD3-receptor subtypes, but did not show significant affinity in strong contrast to analogues without the ketone moiety.

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Communication | Regular issue | Vol 68, No. 5, 2006, pp. 885 - 888
Published online: 31st March, 2006
DOI: 10.3987/COM-06-10691
Synthesis of Isoxazoline-fused Chlorins by 1,3-Dipolar Cycloaddition Reaction of Porphyrins with Alkyl Nitrile Oxides

Stanislaw Ostrowski,* Przemyslaw Wyrebek, and Agnieszka Mikus

*Institute of Chemistry, University of Podlasie, ul. 3 Maja 54, 08-110 Siedlce, Poland


meso-Tetraphenylporphyrin and its β-nitro zinc complex derivative react at higher temperature with unstable alkyl nitrile oxides affording isoxazoline-fused chlorins according to dipolar [3+2]-cycloaddition pathway. The respective nitrile oxides were in situ generated from the corresponding nitroalkanes in the presence of triethylamine and phenyl isocyanate. The products obtained are attractive intermediates for further functionalization of porphyrins and may be of potential use as sensitizers in photodynamic therapy.

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Communication | Regular issue | Vol 68, No. 5, 2006, pp. 889 - 895
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10698
Microwave-promoted Sequential Three-component Synthesis of Tetrahydrobenzo[b]pyran in Water Catalyzed by Heterogeneous Amine Grafted on Silica

Hisahiro Hagiwara,* Ayuko Numamae, Kohei Isobe, Takashi Hoshi, and Toshio Suzuki

*Graduate School of Science and Technology, Niigata University, 8050, 2-Nocho, Ikarashi, Niigata 950-2181, Japan


A variety of tetrahydrobenzo[b]pyrans have been synthesized by sequential addition of arylaldehydes, cyanoacetate and then dimedone in water under microwave irradiation. A heterogeneous amine, N,N-diethylamino-propylated silica, was an effective catalyst for the reaction. The reaction with malononitrile provided the same result. The reaction condition was general to apply to the aldehyde having a Cl, NO2, OH, OMe, or CO2H group in satisfactory yield.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 897 - 914
Published online: 31st March, 2006
DOI: 10.3987/COM-06-10682
3-(Dimethylamino)propenoate-based Regioselective Synthesis of 1,4-Disubstituted 5-Hydroxy-1H-pyrazoles

David Kralj, Jasmin Mecinovic, David Bevk, Uros Groselj, Branko Stanovnik,* and Jurij Svete*

*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, SI-1000 Ljubljana, Slovenia


1,4-Disubstituted 5-hydroxy-1H-pyrazoles (9), (12), and (13) were prepared in two steps from hydrazines (2a-k) and 3-(dimethylamino)propenoates (1), (4), and (5). First, acid-catalyzed treatment of enaminones (1), (4), and (5) with (hetero)arylhydrazines (2a-k) afforded the corresponding dimethylamine substitution products, hydrazones (3’) and enehydrazines (6) and (7). Under acidic conditions, intermediates (3’), (6), and (7) did not undergo cyclization into the pyrazole derivatives. However, heating 3’, 6, and 7 in a mixture of methanol and triethylamine furnished the desired products in 65-98% yields.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 915 - 932
Published online: 28th March, 2006
DOI: 10.3987/COM-06-10683
Selective N-Demethylation of Tertiary Aminofumagillols with Selenium Dioxide via a Non-classical Polonovski Type Reaction

Hong Woo Lee,* Joong Bok Ahn, Jung Hwa Lee, Sung Kwon Kang, Soon Kil Ahn, and Deok-Chan Ha

*Chemical Process Development Lab, New Drug Research Labs, Chong Kun Dang Research Institute, Cheonan P.O. Box 74, Cheonan, 330-831, Korea


The previously unknown selective N-demethylation of tertiary aminofumagillols (5a-e) to the corresponding secondary aminofumagillols (7a-e) is effectively accomplished via a non-classical Polonovski type reaction using selenium dioxide (SeO2). Especially, noteworthy is that two epoxy and the α,β-unsaturated ester functionalities in the fumagillol molecules tolerate in this transformation. Aminofumagillol derivatives are valuable antiangiogenesis inhibitors.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 933 - 947
Published online: 31st March, 2006
DOI: 10.3987/COM-06-10686
A Ready One-pot Preparation for Pteridine and Isoxazolo[3,4-d]pyrimidine Derivatives

José Ma Quintela,* Carlos Peinador,* María J. Moreira, Rosa Toba, and Marcos Chas

*Department of Fundamental Chemistry, Faculty of Sciences, University of A Coruña, Campus A Zapateira E-15071 A Coruña, Spain


Several new substituted pteridines and isoxazolo[5,4-d]pyrimidines are easily obtained by an efficient one-pot procedure from the reaction of N,N-dimethyldichloromethyleniminium chloride (phosgeniminium chloride) with the precursors β-enaminonitriles 2-amino-3-cyano-5-phenylpyrazine (5) and 5-amino-4-cyano-3-methylisoxazole (1), respectively.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 949 - 966
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10688
Synthesis of Methyl 2-[(Benzyloxycarbonyl)amino]-3-cyanopropenoate and Its Transformations into Derivatives of Pyrrole, 2,5-Dioxoimidazolidine, 1H-Pyrazole, and 4,6-Diaminopyridazine

Uros Ursic, David Bevk, Renata Toplak, Uros Groselj, Anton Meden, Jurij Svete,* and Branko Stanovnik*

*Department of Organic Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, P.O. Box 537, SI-1000 Ljubljana, Slovenia


Methyl (E)-2-[(benzyloxycarbonyl)amino]-3-cyanopropenoate (4) was, as a versatile multifunctional reagent, transformed with hydrazine and monosubstituted aromatic and heteroaromatic hydrazines under various conditions into derivatives of pyridazine (6), pyrrole (7), imidazole-2,4-dione (9), and pyrazole (13).

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 967 - 974
Published online: 31st March, 2006
DOI: 10.3987/COM-06-10692
Application of Sulfamic Acid as an Eco-friendly Catalyst in an Expedient Synthesis of Benzimidazoles

Manas Chakrabarty,* Sulakshana Karmakar, Ajanta Mukherji, Shiho Arima, and Yoshihiro Harigaya

*Department of Chemistry, Bose Institute, 93/1, A. P. C. Road, Kolkata-700009, India


Sulfamic acid, an eco-friendly and zwitterionic solid, proved to be a very efficient catalyst for the reaction of ortho-phenylenediamine with aryl aldehydes in ethanol at room temperature to furnish both 1-arylmethyl-2-aryl- and 2-arylbenzimidazoles in very good to excellent overall yields.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 975 - 981
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10700
A Concise Synthesis of Further Thiophene Analogues of Kuanoniamine A

Seon A. Hepburn and Yvette A. Jackson*

*Department of Chemistry, University of the West Indies, Mona, Jamaica, West Indies


An efficient synthesis of three novel 9H-pyrido[6,5,4-kl]thieno[3,2-i]acridin-9-ones is described. The synthesis is achieved utilizing methyl-4,7-dimethoxybenzo[b]thiophene-2-carboxylate.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 983 - 991
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10705
Preparation of Bioactive Isorhapontigenin Dimers through Chemical Transformation of Bisisorhapontigenin A

Chun-Suo Yao and Mao Lin*

*Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Peking Union Medical College, Beijing 100050, P. R. China


Two new stilbene dimers, bisisorhapontigenin E (2) and bisisorhapontigenin F (3), and two novel cyclooligostilbenes, bisisorhapontigenin G (4) and 13b-methoxyl bisisorhapontigenin G (5) were prepared through isomerization reaction of bisisorhapontigenin A with sulfuric acid as a catalyst. Their structures and relative stereochemistry were elucidated on the basis of spectral analysis and their possible formation mechanisms were proposed. The pharmacological activities on anti-inflammation and anti-oxidant of 2-4 have been tested. All of them exhibited potent anti-oxidant activities.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 993 - 1006
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10710
A Convenient Synthesis of Papaverine Analogs via Photocyclization of N-Acyl-α-dehydroarylalaninamide Derivatives

Hideki Hoshina, Kei Maekawa, Kaori Kobayashi, Tetsutaro Igarashi, and Tadamitsu Sakurai*

*Departmnet of Applied Chemistry, Faculty of Engineering, Kanagawa University, Kanagawa-ku, Yokohama 221-8686, Japan


Photochemical cyclizations of (Z)-N-(substituted phenylacetyl)-α- dehydro(3,4-dimethoxyphenyl)alaninamides in methanol were found to proceed regioselectively giving papaverine analogs in satisfactory yields, irrespective of the substituent introduced. MM2 and PM5 calculations revealed that steric hindrance of the methoxy group introduced at the meta-position on the styryl benzene ring is responsible for the regioselective photocyclization observed.

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Paper | Regular issue | Vol 68, No. 5, 2006, pp. 1007 - 1015
Published online: 31st March, 2006
DOI: 10.3987/COM-06-10714
Regioselectivity in 1,3-Dipolar Cycloaddition of 3-(4-Ethoxyphenyl)-4-cyanosydnone with Propargylic Esters

En-Ming Chang, Fung Fuh Wong,* Tse-Hsin Chen, Kuo-Chen Chiang, and Mou-Yung Yeh*

*Sustainable Environment Research Center, National Cheng Kung University, No. 500, Sec. 3, An-ming Rd., Tainan City, Taiwan, R.O.C.


A regioselective 1,3-dipolar cycloaddition of 3-(4-ethoxyphenyl)-4-cyanosydnone with propargylic esters having a bulky alkyl group was developed. This new reaction provided alkyl 5-cyano-1-aryl-1H-pyrazole-3-carboxylate as a major product.

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Note | Regular issue | Vol 68, No. 5, 2006, pp. 1017 - 1023
Published online: 31st March, 2006
DOI: 10.3987/COM-05-10647
Synthesis of 1,5-Benzodiazepine Derivatives Catalysed by Zinc Chloride

Mohamed Afzal Pasha* and Vaderapura Puttaramegowda Jayashankara

*Department of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore-560 001, India


2,3-Dihydro-1H-1,5-benzodiazepines have been synthesized by the condensation of
o-phenylenediamine (OPDA) with cyclic or acyclic ketones in the presence of zinc chloride as catalyst at 80-85 °C. The yields are high and the reactions go to completion within 10-20 min.

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Note | Regular issue | Vol 68, No. 5, 2006, pp. 1025 - 1030
Published online: 24th March, 2006
DOI: 10.3987/COM-06-10695
Asymmetric Diels-Alder Reaction of 2-(p-Tolylsulfinyl)-1-indolyl α,β-Unsaturated Enones

Yoshitsugu Arai,* Takeshi Katori, and Yukio Masaki

*Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585, Japan


The asymmetric Diels-Alder reaction of chiral 1-[2-(p-tolylsulfinyl)indolyl enones was examined. The cycloaddition of cinnamyl and crotonyl α,β-unsaturated enones with cyclopentadiene in the presence of a lanthanoid triflate as a Lewis acid proceeds smoothly to give the corresponding endo cycloadducts with high diastereoselectivity.

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Note | Regular issue | Vol 68, No. 5, 2006, pp. 1031 - 1041
Published online: 28th March, 2006
DOI: 10.3987/COM-06-10718
Synthesis and Structural Analysis of 3,6,8,11,16-Hexahydrodicyclopenta[c,h][1,6]dithiecin

Mitsunori Oda,* Yanmei Zhang, Nguyen Chung Thanh, Shu-ichi Hayashi, Shengli Zuo, and Shigeyasu Kuroda*

*Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto, Nagano 390-0313, Japan


The cycloaddition reaction of 3,6,9-trihydrocyclohepta[c][1,2]dithiin (5), prepared from 3,4-bis(bromomethyl)-1,3,5-cycloheptatriene (3) in two steps, with 3,4-dimethylene-1,5-cycloheptadiene (6) in the presence of boron trifluoride-etherate gave 3,6,8,11,16-hexahydrodicyclohepta[c,h][1,6]dithiecin (2). The temperature-dependent NMR study indicated that 2 possesses the fluxional tetrahydrodithiecin moiety in solution at room temperature. The X-Ray crystal structure analysis showed that 2 has an S-letter shape which was supported as the most stable conformer by DFT molecular orbital calculations.

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15 data found. 1 - 15 listed