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Published online: 26th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-15-13391
A Green, Solvent-Free One-Pot Synthesis of Disubstituted Quinolines via A3-Coupling Using 1 mol% FeCl3

Shivani Naidoo and Vineet Jeena*

*School of Chemistry and Physics, University of KwaZulu-Natal, Cnr Golf and Ridge Roads 3209, South Africa

Abstract

A simple and green route towards disubstituted quinolines via A3-coupling using 1 mol% FeCl3 is described. Using this approach, the above-mentioned derivatives were synthesized in moderate to good yields (45-95%) under solvent-free, microwave conditions. Preliminary investigations have indicated that a further decrease in catalyst amount is possible with a satisfactory yield still observed.

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Published online: 26th July, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13514
Synthesis of 3-Hydroxy-1,3-dihydro-2H-pyrrolo[2,3-b]-, -[2,3-c]-, or -[3,2-c]Pyridin-2-ones from the Respective N-Pyridinylpivalamides and α-Keto Esters

Kazuhiro Kobayashi,* Risa Kosuna, and Yuuki Chikazawa

*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

A convenient synthesis of the title compounds utilizing the reaction of the dilithium compounds, generated in situ by the reaction between N-(pyridin-2-, -3-, or -4-yl)pivalamides and two equivalents of butyllithium in THF, with α-keto esters is described. Thus, N-(3-lithiopyridin-2-yl)pivalamide reacts smoothly leading to the formation of the corresponding α-hydroxy esters. These undergo deprotective cyclization in refluxing hydrochloric acid to afford 3-substituted 3-hydroxy-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-ones. Similarly, starting from N-(pyridin-3- or -4-yl)pivalamides, the corresponding 3-dihydro-2H-pyrrolo[2,3-c]- or -[3,2-c]pyridin-2-one derivatives, respectively, can be prepared.

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Published online: 21st July, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13508
A Facile Preparation of Imidazo[1,2-a]pyridin-3-amine Derivatives via a Three Component Reaction with β-Cyclodextrin–SO3H as Catalyst

Jian Wu,* Fang-Zhou Xu, She-Lei Feng, Wei Xue, and Zhen-Zhen Wang

*Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, China

Abstract

Because heterogeneous catalysts have attracted great interest in organic chemistry, this paper reports facile β-cyclodextrin–SO3H–catalyzed cyclization to form imidazo[1,2-a]pyridin-3-amine derivatives via a three-component reaction. The main advantages of this strategy include short reaction time, practical simplicity, and high yield, and the catalyst can be separated easily by filtration and reused at least four times.

Supporting Info. (3.5MB)PDF (770KB)

Published online: 19th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13511
Two New Alkaloids from the Seeds of Cassia alata and Their Bioactivities

Pei-Song Yang, Wei Zhang, Xiao-Feng Shen, Xin-Lin Wang, Chao Li, Xiao-Wei Gong, Xu-Dong Zheng, Dong-Lai Zhu,* and Jia-Qiang Wang*

*School of Chemical Science and Technology, Yunnan University, Kunming 650091, China

Abstract

Two new alkaloids, 6-(hydroxymethyl)-3,9-dimethyl-7H-benzo[de]quinolin-7-one (1) and 6-(hydroxymethyl)-8-methoxy-3,9-dimethyl-7H-benzo[de]quinolin-7-one (2), together with four known alkaloids (3-6) were isolated from the seeds of Cassia alata. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1-6 were tested for their anti-tobacco mosaic virus (TMV) activities, and the results showed that compound 2 exhibited high anti-TMV activity with inhibition rates of 38.5%. This rate is higher than that of the positive control. The cytotoxicities of compounds 1-6 against five human tumor cell lines (NB4, A549, SHSY5Y, PC3 and MCF7) were also tested. Compounds 1-6 showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 2.5-7.5 μM.

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Published online: 15th July, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13503
Facile Synthesis of Sulfonyl Amidines by 1,3-Dipolar Cycloaddition between 1-Morpholinocycloalkenes and Sulfonyl Azides without Catalyst

Chiaa Adiche, Mohammed Hamadouche, and Douniazad El Abed*

*Chemistry Department, Faculty of Exact and Applied Sciences, University of Oran 1, Ahmed BenBella, BP 1524 El M’naouar, Oran 31000, Algeria

Abstract

Three new series of sulfonyl amidines were prepared by 1,3-dipolar cycloaddition reaction between 1-morpholinocycloalkenes and various substituted sulfonyl azides without catalyst at room temperature. This reaction yielded unstable bicyclic Δ2-1,2,3-triazoline intermediates which rearranged themselves in situ into amidines by elimination of a nitrogen molecule. The reactions were performed under mild conditions and with moderate to good yields.

Supporting Info. (1.8MB)PDF (421KB)

Published online: 15th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13506
Lewis Acid-Catalyzed Borono-Minisci Reactions of Arylboronic Acids and Heterocycles

Joyce L. Biaco, Savannah L. Jones, and Timothy J. Barker*

*Department of Chemistry and Biochemistry, College of Charleston, 66 George St., Charleston, SC 29424, U.S.A.

Abstract

A Lewis acid-catalyzed Minisci reaction between arylboronic acids and heterocycles has been developed. This radical-coupling reaction was demonstrated employing several different heterocycles as well as electron-rich arylboronic acids. Quinoline substrates afforded modest regioselectivity for substitution at the 4-position under the reaction conditions, in contrast to previously reported Brønsted acid-mediated reactions with quinoline substrates that favored substitution at the 2-position.

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Published online: 13th July, 2016

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)9
Preparation and Biological Activity of Novel Twin-Drug Type C2-Symmetrical Cyclic Phenylboronic Acid Derivatives

Makoto Furutachi, Ayumi Ejima, Reika Tsuru, Saho Goto, Toshiaki Gondo, Kenta Ako, Saho Fuchigami, Saya Fujii, Arisa Okumura, Ayumi Tozuka, Kazumi Yokomizo, Jian-Rong Zhou, Hiroshi Inao, Yutaro Ono, Nobuhiro Kashige, Fumio Miake, and Kunihiro Sumoto*

*Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

Abstract

We here report the results of evaluation of antibacterial and anti-herpes simplex virus-1 (HSV-1) activities of a novel twin-drug type C2-symmetrical boronic acid and its pinacol ester derivatives. By using a primitive amide bond formation reaction, various targeted C2-symmetrical cyclic phenylboronic acid derivatives were obtained from the reactions of commercially available amino-substituted phenylboronic acid derivatives and diacid dichlorides. The C2-symmetrical bivalent molecule 3bd containing two cyclic phenylboronic acid pinacol ester moieties and a flexible hexamethylene linker showed both antibacterial activity (S. aureus) and anti-HSV-1 activity. The corresponding boronic acid derivative 3dd showed neither antibacterial nor anti-HSV-1 activity, indicating the importance of two pinacol ester functionalities.

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Published online: 12th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13510
KH2PO4 Promoted Practical and Environmentally Friendly Preparation of Coumarin-3-carboxylic Acids under Solvent-Free Condition

Shuangqiu Gao, Di Xiao, Ying Yang, Xiaoyü Wei, Sai Sun, Jian Lang, and Chengwei Lv*

*School of Chemistry and Chemical Engineering, Liaoning Normal University, No.850 Huanghe Road, Liaoning Province 116029, China

Abstract

An efficient and green protocol for synthesis of coumarin-3-carboxylic acids is developed in good to high yields via a Knoevenagel-intramolecular cyclization cascade reaction of Meldrum’s acid with various ortho-hydroxyarylaldehydes. This reaction is catalyzed by a combination of KH2PO4 (10 mol%) and water (100 μL). Solvent-free, cheap and eco-friendly catalyst, clean reaction conditions, simple workup procedure and easy isolation are the best features in this process.

Supporting Info. (539KB)PDF (325KB)

Published online: 11th July, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13484
An Efficient and Practical Preparation of a Potent Low-Affinity Na+-Dependent Glucose Cotransporter (SGLT2) Inhibitor, Sergliflozin Etabonate

Masahiro Kobayashi,* Hidetoshi Isawa, Junichi Sonehara, and Minoru Kubota

*Quality Assurance, Kissei Pharmaceutical Co., Ltd, 19-48 Yoshino, Matsumoto-City, Nagano-Pref., Japan

Abstract

The development of an efficient and practical process for the preparation of Sergliflozin etabonate (1), a prodrug of a novel selective low-affinity Na+-dependent glucose cotransporter (SGLT2) inhibitor, Sergliflozin (2), is described. Its development required a suitable process for large-scale manufacturing. We established a chromatography-free approach for 2-[(4-methoxyphenyl)methyl]phenol (5), the efficient O-glycosylation of 5 with penta-O-acetyl-β-D-glucopyranose (7) without using a trichloroimidate intermediate (9), and efficient reaction conditions to introduce an ethoxycarbonyl group onto the primary alcohol of 2 with high selectivity. This process provided 1 with a 45% overall yield from anisole (10).

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Published online: 7th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13501
Synthesis of Isoquinolinium via Rhodium(Iii)-Catalyzed Oxidtive Annulation between Aldimines and Alkynes

Cheng-Qi Wang, Wei Zhang, Hui Lin, Fu Su,* and Lin Dong*

*West China School of Pharmacy, Sichuan University, 17# Third Section of South Renmin Road 610041, China

Abstract

Various isoquinolinium salts have been efficiently synthesized from aldehyde imines and alkynes via RhIII-catalyzed C–H activation and annulation reaction. A broad substrate scope has also been studied to provide various isoquinolinium triflate salts.

Supporting Info. (3.6MB)PDF (575KB)

Published online: 5th July, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13495
Skeletal Transformation of 2a,8b-Dihydrobenzo[b]cyclobute[d]pyran-3-ones into Dihydrodibenzofurans

Toru Tanaka, Masaki Nagahama, Navnath Dnyanoba Yadav, Hiroki Iwasaki, Minoru Ozeki, Naoto Kojima, and Masayuki Yamashita*

*Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi, Yamashina, Kyoto, Japan

Abstract

Using dimethylsulfoxonium methylide as the methylene-transfer reagent, 8-methoxy-2a,8b-dihydrobenzo[b]cyclobute[d]pyran-3-ones were exclusively converted into the corresponding dihydrodibenzofuran derivatives. The use of a methoxy group as the substituent and its position are crucial to the success of this transformation.

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Published online: 30th June, 2016

Paper | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)4
Isolation and Evaluation of Hedgehog Inhibitors from Christmas Grass (Themeda arguens)

Tatsuro Yoneyama, Midori A. Arai,* Takashi Koyano, Thaworn Kowithayakorn, and Masami Ishibashi*

*Department of Natural Products Chemistry, Graduate School of Pharmaceutical Science, Chiba University, 1-8-1 Inohana, Chuo, Chiba, Japan

Abstract

The hedgehog (Hh) signaling pathway is an important regulator of embryonic development, tissue patterning, cellular proliferation and differentiation. However, aberrant activation of the pathway is associated with tumorigenesis. In this study, the Hh signal inhibitory activity of plant extracts was measured with a cell-based assay system that targets GLI1-mediated transcription. Activity guided analysis of MeOH extracts of christmas grass (Themeda arguens) led to the isolation of four inhibitory compounds: aciculatin (1), 7-de-O-methylaciculatin (2), 8-C-β-D-boivinopyranosylapigenin (3) and aciculatinone (4). Compound 1 strongly inhibited Hh/GLI1-mediated transcriptional activity with an IC50 value of 1.8 μM, and disrupted the formation of the GLI1-DNA complex by EMSA. 1 and 3 were cytotoxic for human prostate (DU-145) and breast (MCF-7) cancer cells. These compounds may serve as new tools for the molecular dissection of Hh pathway activation.

Supporting Info. (129KB)PDF (1.6MB)

Published online: 24th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13487
Catalyst-Free Synthesis of 1-Phenylnaphtho[2,1-b]furan Derivatives under Microwave Irradiation

Baolong Wang, Jinfu Zhang, Jianhong Liao, Yiyuan Peng, and Hua Zheng*

*School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 122 Luoshi Road,Wuhan,Hubei 430070, China

Abstract

An environmentally benign and efficient method has been developed for the synthesis of naphtho[2,1-b]furan from (E)-(2-nitrovinyl)benzene and naphthalen-2-ol in brine media under catalyst-free conditions through microwave-assisted technology. The advantages of this process are that it is catalyst-free, has an easy work-up, provides good yields, and uses brine as the solvent which is considered to be relatively environmentally benign.

Supporting Info. (2.5MB)PDF (993KB)

Published online: 24th June, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13483
Synthesis, Characterization and Cytotoxicity Evaluation of Some Novel Pyrazole, Pyrimidine and Isoxazoloe Drivatives Containing Benzothiazole Moiety

Khaled. S. Mohamed,* Hala M. Refat, and Nada A. H. Mohamed

*Engineering Chemistry Department, Higher Institute for Engineering and Technology, New Damietta, New Damietta 34518, Egypt

Abstract

The 2-(2-benzothiazolyl)-3-(2-methoxy-1-naphthyl)acrylonitrile (3) was used as precursor for the synthesis of some novel pyrazole, isoxazole, pyrimidine derivatives and other related products containing benzothiazole moiety via the reaction of compound 3 with appropriate chemical reagents. The structures of the newly synthesized products were confirmed by elemental analyses, IR, 1H-NMR, 13C-NMR and mass spectral data. These compounds were screened for their antitumor activities. Compound 7 displayed promising in vitro antitumor activity in the four cell lines assay.

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Published online: 22nd June, 2016

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)5
Synthesis of (±)-Cephalanthrin A Using Baeyer-Villiger Oxidation

Tomoki Itoh, Takumi Abe, Tominari Choshi, Takashi Nishiyama, and Minoru Ishikura*

*School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan

Abstract

Indoloquinazoline alkaloid (±)-cephalanthrin A was synthesized through the Baeyer-Villiger oxidation of the phenyl ketone derived from aldol reaction of tryptanthrin and acetophenone.

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Published online: 20th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13470
DABCO-Catalyzed Green Synthesis of Thiazole and 1,3-Thiazine Derivatives Linked to Benzofuran

Sobhi M. Gomha, Mohamed G. Badrey, and Wael A. A. Arafa*

*Department Of Chemistry, Fayoum University, Fayoum 12975, Egypt

Abstract

An eco-friendly and simple procedure for the reaction of 2-(1-(benzofuran-2-yl)ethylidene)hydrazinecarbothioamide with arylidenemalononitriles and hydrazonoyl halides catalyzed by using sterically hindered organic base, 1,4-diazabicyclo[2.2.2]octane (DABCO) was described. This new protocol has the advantage of good yields and short reaction times. The structure of the newly synthesized compounds was elucidated via elemental analyses and spectral data.

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Published online: 20th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13482
Two New 2-Arylbenzofurans from the Stems of Nicotiana tabacum and Their Bioactivities

Pei-Song Yang, Wei Zhang, Xiao-Feng Shen, Xin-Lin Wang, Chao Li, Xiao-Wei Gong, Xu-Dong Zheng, Dong-Lai Zhu, and Jia-Qiang Wang*

*School of Chemical Science and Technology, Yunnan University, Kunming 650091, China

Abstract

Two new 2-arylbenzofurans, 4-(7-methoxy-3,5-dimethyl-benzofuran-2-yl)phenol (1), 4-(6-methoxy-3,5-dimethylbenzofuran-2-yl)-phenol (2), together with two known 2-arylbenzofurans (3 and 4) were isolated from the stems of Nicotiana tabacum. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1-4 were tested for their anti-TMV and cytotoxicity activities. The results showed that compound 2 exhibited high anti-TMV activities with inhibition rates of 36.4% at the concentration of 20 μM. This rate is higher than that of positive control. Compounds 1-4 showed moderate-to-weak cytotoxicities against some tested human tumor cell lines with IC50 values in the range of 2.2–8.4 μM.

Supporting Info. (650KB)PDF (1.3MB)

Published online: 20th June, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13491
One-Pot and Three-Component Synthesis, Characterization and Biological Evaluation of Some New 1,2,4-Triazine-coumarins

Guang-cheng Wang,* Jing Wang, Dian-xiong He, Xin Li, Juan Li, and Zhi-yun Peng

*College of Chemistry and Chemical Engineering, Jishou University, Jishou University, Jishou 416000, China

Abstract

A series of 1,2,4-triazine-coumarins were prepared by a one-pot, three-component condensation of 1,2-diarylethane-1,2-diones, thiosemicarbazide and 2-coumaryloxy-methyloxiranes using K2CO3 as a catalyst in aqueous medium. This three-component reaction offers several advantages such as simple procedure, environmentally friendly and high yields. The resulting products were characterized by 1H NMR, 13C NMR and melting points. Furthermore, all newly synthesized compounds were evaluated for their α-glucosidase inhibitory activity. As a result, the majority of the screened compounds displayed potent inhibitory activity with IC50 values in the range of 32.57±0.21 to 148.77±3.23 μM, when compared to the standard acarbose (IC50 = 876.14±2.46 μM).

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Published online: 17th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13497
Oxidative Synthesis of Isoxazoline-N-oxide from Optically Active Nitro Alcohols

Takaaki Moriyama, Takuji Kawamoto, Hidemitsu Uno, and Akio Kamimura*

*Department of Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, , Japan

Abstract

Treatment of optically active 6-nitrohex-1-en-3-ols with Ag2O and iodine under basic conditions resulted in an oxidative intramolecular cyclization reaction to give isoxazoline-N-oxide along with bicyclo[3.1.0]hexane. The stereoselectivity and chemoselectivity of the reaction depended on the configuration of the stereogenic center adjacent to the alkenyl group. The structure was determined by X-ray crystallographic analyses as well as coupling constants from NMR data. Stereochemical preferences in the transition structure of the reaction are discussed.

Supporting Info. (1.7MB)PDF (389KB)

Published online: 13th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13437
Preparation and Electrochemical Behavior of N-Substituted Phenothiazine Oxide

Hideki Hayashi* and Take-aki Koizumi

*Organic Materials Laboratory, Nagoya Municipal Industrial Research Institute, 3-4-41, Rokuban, Atsuta-ku, Nagoya 456-0058, Japan

Abstract

The chemical properties of promazine oxide (Prom-O) and promazine (Prom) were compared. Cyclic voltammetry (CV) experiments showed a higher oxidation potential of Prom-O compared to that of Prom. The results of CV measurements also suggested the potential applicability of Prom-O as an n-type semiconductor.

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Published online: 9th June, 2016

Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13467
A Simple and Convenient Synthesis of Isolated Fused Heterocycles Based on: 6-Phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one and 5-Acetyl-6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one

Mohamed Ahmed Mahmoud Abdel Reheim,* Ibrahim Saad Abdel Hafiz, and Mohamed Ahmed Elian

*Department of Chemistry, Faculty of Science, Suez Canal Univeristy, Arish 45511, Egypt

Abstract

The reaction of 6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one 1 with acetylchloride in acetic anhydride in the presence of sodium acetate afforded 5-acetyl-6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one 2 which reacted with bromine, hydrazine hydrate, phenylhydrazine, cyanothioacetamide, aldehydes and (malononitrile/sulfur) to give 2-thioxo-2,3-dihydropyrimidine derivatives 4, 7a,b, 8, 10 and 11 respectively. In the present investigation 6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one 1 was reacted with chloroacetylchloride yielded the corresponding compound 13. Compound 1 was reacted with some electrophilic reagents such as (benzylidene cyanothioacetamide derivatives, 2-cyano-2-cyclopentylethanethioamide, 2-cyano-2-cyclohexylethanethioamide and aromatic diazonium salts) to give compounds 23, 27a,b and 35 respectively. The newly synthesized heterocycles were characterized on the basis of their chemical properties and spectral data.

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Published online: 9th June, 2016

Communication | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)1
A Water-Soluble Cavitand Sequesters 2-Nonenal, the Odor Component of the Elderly

Yang Yu, Simone Mosca, and Julius Rebek, Jr.*

*Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, U.S.A.

Abstract

Long chain aldehydes are principal components of odor in older populations. Here we show that a synthetic container molecule, a deep water-soluble cavitand forms complexes in aqueous (D2O) solution. The cavitands bind the aldehyde in a compressed conformation that reduces exposure to the medium. The aldehyde is extracted from the complex by tetrachloroethane and sodium dodecyl sulfate, chemical agents of dry cleaning or laundering, respectively. The large-scale synthesis of the cavitand opens possibilities for its attachment to clothing fibers.

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Published online: 9th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13499
A Convenient Synthetic Route for Substituted 1-(Aryldiazenyl)Imidazo[1,5-a]Pyridine

Mustafa M. El-Abadelah,* Hamdallah A. Hodali, Monther S. Zreid, Firas F. Awwadi, Mohammed M. Abadleh, and Wolfgang Voelter

*Department of Chemistry, Faculty of Science, The University of Jordan, Amman 11942, Jordan

Abstract

In the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), model 2-(N'-aryl)picolinohydrazonamides 7, 8 (derived from interaction of the respective ethyl glycinate and (2-pyridyl)methylamine with the particular hydrazonoyl chloride) underwent didehydrogenation with concomitant heterocyclization to deliver the corresponding 1-(aryldiazenyl)imidazo- [1,5-a]pyridines 9, 10. Structures of the latter bicyclic systems are deduced from spectral data and confirmed by X-ray diffraction analysis of the Pd-complex 11, derived from 9.

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Published online: 9th June, 2016

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-16-13498
Intramolecular 1,3-Dipolar Cycloaddition of Diazido-terminal Dialkynes: Synthesis of New Polyoxyethylene Fused exo-Bis(1,2,3-triazolo-1,4-oxazines)

Nejib Hussein Mekni*

*Organic Structural Chemistry Laboratory, Synthesis and Physico-Chemical Studies, Department of Chemistry, University of Tunis El-Manar, 2092 Tunis, Tunisia

Abstract

The synthesis of new tetraheterocyclic 1,5-disubstituted exo-heterocyclic polyoxyethylene bis(1,2,3-triazolo-1,4-oxazine) is achieved through nucleophilic azide ion ring opening reaction on polyoxyethylene dioxiranes, followed by an O-propargylation, then thermal uncatalyzed 1,3-dipolar intramolecular cycloaddition.

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Published online: 7th June, 2016

Paper | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)3
Synthesis of 3-Bromoquinoline-2(1H)-thiones and 2-(Alkylsulfanyl)-3-bromoquinolines Based on the Reaction of 2-(2,2-Dibromoethenyl)phenyl Isothiocayanates with Butyllithium

Kazuhiro Kobayashi,* Ippei Nozawa, and Takashi Nogi

*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

The synthesis of 3-bromoquinoline-2(1H)-thiones and 2-(alkylsulfanyl)-3-bromoquinolines from readily available starting materials was accomplished. Thus, 2-(2,2-dibromoethenyl)phenyl isothiocyanates were treated with butyllithium to afford, after aqueous workup, 3-bromoquinoline-2(1H)-thiones. When haloalkanes were added prior to workup, 2-(alkylsulfanyl)-3-bromoquinolines were obtained. An elaboration of one of these compounds to a thieno[2,3-b]quinoline derivative and one-pot preparation of 3-substituted quinoline-2(1H)-thiones were also achieved.

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Published online: 3rd June, 2016

Review | Regular issue | Prepress
DOI: 10.3987/REV-16-842
Development of Solvent-Driven Iron-Catalyzed Reactions

Toshiyuki Itoh*

*Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

The possibility of solvent-driven iron-catalyzed reactions has been investigated using ionic liquids and acetonitrile as key solvents. Three iron-catalyzed reactions, the intramolecular cyclization of cyclopropane dithioacetals, the [2+2]-cycloaddition of (trans)-anethole, and the [2+3]-type cycloaddition of styrene derivatives with 1,4-benzoquinone, were first developed using acetonitrile as solvent in the presence of 3~5 mol% of Fe(ClO4)3Al2O3 or Fe(BF4)26H2O under air conditions. In particular, we found the rapid cycloaddition of iron-catalyzed [2+3]-type cycloaddition of styrene derivatives with 1,4-benzoquinone when the reaction was carried out in an ionic liquid which contained [PF6] or [Tf2N] anion. Homo-coupling reaction of aryl or alkynyl Grignard reagent was next discovered using 1 mol% of FeCl3 as catalyst and the reaction also proceeded very rapidly in an ionic liquid. We also found that 3~5 mol% of Fe(ClO4)2Al2O3 or Fe(BF4)26H2O-successfully catalyzed Friedel-Crafts type alkylation of indoles or pyrroles with vinyl ketones or α-aryl-β-silylalcohol. In particular, the reaction of chiral α-aryl-β-silylalcohol with indole using Fe(ClO4)3nH2O as catalyst proceeded with retention of the configuration of stereochemistry of the hydroxyl group. Then, we discovered the first example of iron-catalyzed enantioselective C-S bond formation via Michael addition of thiols to (E)-3-crotonoyloxazolidin-2-one using 10 mol% of Fe(BF4)2/Pybox. We further demonstrated that Fe(ClO4)3Al2O3-catalyzed the Nazarov type cyclizations of thiophene, pyrrole, indole, benzofuran, and benzo[b]thiophene derivatives using ionic liquids as solvent. Solvents have been recognized as a by-player in chemical reactions in the process of “optimization of reaction conditions”. However, further investigation of the solvent-driven iron-catalyzed reaction will allow discovery of useful reactions for organic syntheses.

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Published online: 2nd June, 2016

Paper | Special issue | Prepress
DOI: 10.3987/COM-16-S(S)2
Synthetic Study towards Construction of Potential Scaffold of Antitumor Agents Andrastins

Shuqiang Yin, Kenji Sugimoto, Hideo Nemoto, and Yuji Matsuya*

*Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan

Abstract

For a construction of potential scaffold of antitumor agents andrastins, intramolecular Diels-Alder reaction of the triene composed of trans-fused AB ring with tethered D ring was examined. The reaction in refluxing toluene afforded a desired cis-fused hydrindane skeleton, the relative stereochemistries of which were unambiguously determined by X-ray crystallographic analysis.

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Published online: 28th March, 2016

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-15-S(T)18
Synthesis of Phenantroline and Indole Based Hybrid Cyclophane Derivatives via Ring-closing Metathesis

Sambasivarao Kotha,* Mukesh E. Shirbhate, Ajay Kumar Chinnam, and Gaddameedi Sreevani

*Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai - 400076, India

Abstract

Here, we report new phenanthroline-based cyclophane derivatives via Fischer indolization and ring-closing metathesis (RCM) as key steps. Grignard addition of 2 and subsequent autoxidation gave the phenanthroline dione derivative 3. Further, Fischer indolization of 3 followed by RCM under mild reaction conditions gave indole and phenanthroline containing hybrid cyclophanes such as 6a and 6b.

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Published online: 1st February, 2016

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-15-S(T)48
Synthetic Studies toward Concavine: Synthesis of The BCD Ring Syste

Yosuke Komori, Akitoshi Kozen, and Masahiro Toyota*

*Team TOYOTA, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 593-8531, Japan

Abstract

The BCD ring system of concavine is realized stereoselectively using a palladium-catalyzed cycloalkenylation to synthesize the CD ring and an intramolecular aza-Michael reaction to append the third ring.

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Published online: 12th January, 2016

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-15-S(T)26
Antiproliferative Activity of Hybrid Compounds Between 6-Methoxy-3-(4-Methoxyphenyl)-1H-Indole and 3-Phenylpiperidine Against HCT-116 and HL-60 Cells

Noriyuki Hatae,* Takashi Nishiyama, Shoko Tamura, Ryohei Yamamoto, Ayaka Matsui, Hiroki Shinchi, Satoshi Hibino, Chiaki Okada, Teruki Yoshimura, Tominari Choshi, and Eiko Toyota*

*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan

Abstract

Indole derivatives have been potential anticancer drugs. Methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate, in particular, was reported as a potent antiproliferative agent against MCF-7, NCI-H460, and A375-C5 tumor cells. In this study, the 3-arylindole-2-carboxylate exhibited weak activity against HCT-116 colon tumor and HL-60 promyelocytic leukemia cells. To develop the potent antiproliferative indole derivatives against HCT-116 and HL-60 cells, we synthesized 6-methoxy-3-(4-methoxyphenyl)-1H-indoles with various 2-substituents and assessed their activity. The 4-phenylpiperidine derivatives attenuated the tumor cells viability. Furthermore, their calculated structure resembled that of the antiproliferative loperamide derivatives.

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