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18 data found. 1 - 18 listed

Published online: 22nd September, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13799
Three New C-Alkylated Flavones from the Flower of Rosa Rugosa and their Bioactivity

Jing Li, Huan-Huan Xing, Wei-Song Kong, Ye-Kun Yang, Lin Ye, Xin Liu, Yan-Ping Li, Gao-Xiong Rao, Hai-Ying Yang, Gang Du, Min Zhou, Qiu-Fen Hu, Guang-Yu Yang, Yun-Hua Qin,* and Xue-Mei Li*

*Key Laboratory of Tobacco Chemistry of Yunnan Province, China Tobacco Yunnan Industry Company, Hongjin Road 181#, Kunming, 650231, China

Abstract

Three new C-alkylated flavones (1-3), together with three known C-alkylated flavones (4-6), were isolated from the flower of Rosa rugosa. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1-6 were evaluated for their anti-methicillin- resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compound 1 showed good inhibition with inhibitaion zone diameter (IZD) of 13.4 ± 1.0 mm. Compounds 2-6 also showed weak inhibition with IZD in the range of 7.6 – 11.2 mm, respectively. Compounds 1-3 were also tested for the antioxidant activity, and they shows good antioxidant activity with an IC50 value of 4.2, 3.6 and 3.4 μg/mL, respectively.

Supporting Info. (366KB)PDF (495KB)

Published online: 21st September, 2017

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13779
A Convenient Synthesis of Novel Coumarin Derivatives with Anticipated Antimicrobial Activities

Asmaa Kamal Mourad,* Abd El-Naby Ibrahim Essawy, and Hussein Abdel-Azim Younus

*Faculty of Science, Department Of Chemistry, Fayoum University, Fayoum 63514, Egypt

Abstract

Chalcone and coumarin are two substantial classes of natural products possessing significant antimicrobial activities. Hybrid compounds containing both structures have been synthesized in a good yield using Claisen-Schmidt aldolic condensation. The reaction of the new chalcones with active methylene compounds under different reaction conditions led to the construction of pyridine, pyran, pyrazole and pyridinone containing coumarin moiety with different functional groups. Investigating the antimicrobial activity of the new synthesized heterocycles, displays that 3-(2′-amino-3′-cyano-4′-(4-hydroxy-3-methoxyphenyly)pyrid-6′-yl)-coumarin 2a has the highest antimicrobial activity toward both Gram-positive and Gram-negative bacteria. Consequently, it was utilized as starting material for synthesis of more new fused heterocycles with anticipated high biological activity. All the new compounds are well characterized using, elemental analysis, FT-IR, 1H NMR, ESI-Mass Spectrum and tested for their antimicrobial activity.

PDF (703KB)

Published online: 21st September, 2017

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13801
AlCl3-Promoted Cyclization of β-Keto Derivatives with in situ Generated Enamines under Solvent-Free High Speed Ball Milling: An Efficient One-Pot Access to Polysubstituted 1,4-Dihydropyridines

Ji-Chao Zeng, Fei Yu, Abdullah M. Asiri, Hadi M. Marwani, and Ze Zhang*

*School of Biological & Chemical Engineering, Anhyui Polytechnic University, No. 8, Beijing Road, Wuhu 241000, China

Abstract

Under high speed ball milling (HSBM), a simple method for efficient synthesis of structurally diverse polysubstituted 1,4-dihydropyridines is developed via AlCl3-promoted Robinson-like cyclization of β-keto derivatives with in situ generated enamines. This one-pot protocol exhibits the advantages of high chemoselectivity, short reaction time, good functional group tolerance, mild reaction condition and easy work-up.

Supporting Info. (5.1MB)PDF (732KB)

Published online: 21st September, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13802
Synthesis and Crystal Structure of 4-Trifluoroacetyl-3-Phenylsydnone

Masami Kawase,* Ryosuke Saijo, Shigeki Mori, and Hidemitsu Uno

*Faculty of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime 790-8578, Japan

Abstract

4-Trifluoroacetyl-3-phenylsydnone was first synthesized by trifluoromethylation of 4-formyl-3-phenylsydnone followed by oxidation of the corresponding trifluoromethyl alcohol. The structure of the product was determined by single-crystal X-ray analysis.

PDF (428KB)

Published online: 15th September, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13795
Synthesis of 8,9-Dihydropyrimido[4,5-e][1,4]oxazepin-7(5H)-ones by the Reaction of 1-(4-Chloropyrimidin-5-yl)alkan-1-ols with N-Alkylglycines

Kazuhiro Kobayashi,* Takashi Nogi, Yuka Tsunomori, Hidetaka Hiyoshi, and Kazuto Umezu

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

Abstract

A facile method for the construction of a new ring system, 8,9-dihydropyrimido[4,5-e][1,4]oxazepin-7(5H)-one, is described. The key feature of the synthetic route includes substitution of one of the two chloro groups of 1-(4,6-dichloropyrimidin-5-yl)alkan-1-ol derivatives, which can easily be derived from the reaction between 5-lithiated compound of 4,6-dichloro-2-(methylsulfanyl)pyrimidine (DCSMP) and aldehydes, with N-alkylglycines in the presence of triethylamine, followed by lactonization of the resulting hydroxy acids catalyzed by in situ generated triethylamine hydrochloride.

PDF (155KB)

Published online: 14th September, 2017

Review | Regular issue | Prepress
DOI: 10.3987/REV-17-866
Oxidative Syntheses and Ring Opening of Oxazolines and Related Compounds by Ammonium Tribromide

Shinsei Sayama*

*Natural Sciences (Chemistry), Fukushima Medical University, Hikarigaoka, Fukushima, 960-1295, Japan

Abstract

Oxidative syntheses and ring opening of oxazolines and related compounds with trimethylphenylammonium tribromide (phenyltrimethylammonium tribromide, PTAB) or pyridinium hydrobromide perbromide (PHPB) were summarized. PTAB and PHPB were effective for respective syntheses of oxazolines, dihydrooxazines, and 6-bromobenzothiazoles. PTAB was also available for the conversion of oxiranes to dioxanes in the presence of 1,3-propanediol. The oxidative ring opening of furans, oxazolines, and dioxanes to respective furanones, cyanomethyl esters, and hydroxypropyl esters with PTAB or PHPB was also described.

PDF (1.2MB)

Published online: 8th September, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-12951
Efficient Synthesis of Seven-Membered Cyclic Ethers Using Pd(II) Catalyst

Masahiro Miyazawa,* Yusuke Yano, Chiaki Hayashi, Masatake Okuno, Kenta Hara, Yoshiro Hirai, and Hajime Yokoyama

*Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan

Abstract

We report a palladium(II)-catalyzed intramolecular cyclization of oct-2-ene-1,8-diol derivatives to afford seven-membered cyclic ethers without the need for high dilution and without dimer formation.

PDF (239KB)

Published online: 4th September, 2017

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13781
Synthesis of Azulene-Substituted Tetraarylpyrroles by Reaction of 1-Azulenyl Ketones with Benzoin and Ammonium Acetate

Taku Shoji,* Sho Takagaki, Miwa Tanaka, Takanori Araki, Shuhei Sugiyama, Ryuta Sekiguchi, Akira Ohta, Shunji Ito, and Tetsuo Okujima

*Department of Chemistry, Faculty of Science, Shinshu University, Asahi 3-1-1, Matsumoto, Nagano 390-8621, Japan

Abstract

Tetraarylpyrroles with a 1-azulenyl substituent were prepared by the reaction of 1-azulenyl ketones, which have various aryl-substituents at their α-position, with benzoin in the presence of ammonium acetate as a nitrogen source of the pyrrole ring. Optical property of the tetraarylpyrroles obtained by the reaction was clarified by UV/Vis spectroscopy and/or time-dependent density functional theory (TD-DFT) calculations

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Published online: 25th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13772
Synthesis of (5,6-Dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl)-methanamine

Zhong-Gang Bai, Hui Qi, Qun-Zheng Zhang, Yu Ma, Qing Pan, and Xun-Li Zhang*

*College of Chemistry and Chemical Engineering, Xi’an Shiyou University, 18, 2nd Dianzi Road, Xi’an, Shanxi 710065, China

Abstract

This short paper reports the development of a new method for the synthesis of (5,6-dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl)methanamine. Pyrazole was initially protected with an N-SEM protective group, followed by alkylation at C-5 position with 1-bromo-3-chloropropane. Following SEM deprotection, the intramolecular ring was closed and then a bromine atom (Br) was introduced with N-bromosuccinimide (NBS) by electrophilic aromatic substitution (SEAr), forming 3-bromo-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole. The Br group was subsequently converted into aldehyde group, then into oxime. The final step of hydrogenation resulted in the desired product. The overall yield through the 8-step reaction process was found to be 29.4%. The intermediates and final product were identified by HPLC-MS and 1H NMR. This development provides a novel synthetic route to the formation of 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole skeleton.

Supporting Info. (332KB)PDF (365KB)

Published online: 24th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13769
Selenium Dioxide Mediated Benzylic sp3 C-H Oxidation in Acetic Acid: Synthesis of Lophine Derivatives from α-Methylene Ketones via a Domino Multicomponent Reaction

Vineet Jeena* and Mncedisi Mazibuko

*School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, 3209, South Africa

Abstract

We report a selenium dioxide/acetic acid catalysed one-pot conversion of α-methylene ketones to 1,2-diaryldiketones as a key step to successfully access lophine derivatives in a domino multicomponent reaction.

Supporting Info. (2.3MB)PDF (402KB)

Published online: 17th August, 2017

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13766
Synthesis and Biological Evaluation of Triazolyl Monastrol Analogues Using Cu-Catalyzed Click Chemistry

Hani Mutlak A. Hassan,* Iuliana Denetiu, Kaltoom Sakkaf, Khalid A. Khan, Peter N. Pushparaj, and Kalamegam Gauthaman

*King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589 80216, Saudi Arabia

Abstract

The synthesis of triazolyl monastrol analogues through a Cu(I)-catalyzed [3+2] azide-alkyne cycloaddition (CuAAC) reactions and their biological evaluation against cancer cell lines is described.

PDF (413KB)

Published online: 17th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13784
Ultrasound Promoted Efficient Construction of Polycyclic-Fused Pyrazolo[4,3-c]pyridines via Domino Reaction

Ting Zhou, Dao-Lin Wang,* Jiao Xu,* Liang Yan, and Wei Ma

*College of Chemistry and Chemical Engineering, Bohai University, 19, Keji Rd., New Songshan District, Jinzhou City, Liaoning Province 121001, China

Abstract

Ultrasonic-accelerated rapid protocol for the synthesis of polycyclic-fused pyrazolo[4,3-c]pyridines via SN2/Thorpe-Ziegler/Thorpe- Guareschi domino reactions of 4-acetyl-5-bromomethyl-1-phenyl-1H-pyrazole with salicylonitriles (2-mercaptobenzonitrile or 3-cyanopyridine-2(1H)-thiones). Ultrasoundbased methodology performed better than the conventional process in rates and yields.

PDF (302KB)

Published online: 9th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13760
Choline Chloride Catalyzed Eco-Friend and Effective One-Pot Synthesis of 9-Arylacridine-1,8-dione and Hexahydroquinoline via Hantzsch Type Reaction

Shengxue Mao, Fei Li, Yue Lv, Chengwei Lv,* and Shijun Yu*

*School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, China

Abstract

Choline chloride was utilized to efficiently catalyzed Hantzsch type reaction for the synthesis of 9-arylacridine-1,8-dione and hexahydroquinoline derivatives. The optimized catalytic system benefits from facile operation and separation procedures, in good to excellent yields, and for wide substrate tolerance. This methodology is of interest also due to employing simple and inexpensive choline chloride as catalyst and environmentally benign ethanol as solvent without the use of any harmful organic solvent and toxic metal catalyst.

Supporting Info. (4.6MB)PDF (330KB)

Published online: 9th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13768
Three New Lactone-Type Diterpenoid Alkaloids from Aconitum rotundifolium Kar. & Kir.

Firas Obaid Arhema Frejat, Wenliang Xu, Lianhai Shan, and Xianli Zhou*

*School of Life Science and Engineering, Southwest Jiaotong University, NO.111, North Second Ring Road Chengdu 610031, Sichuan, China

Abstract

Three new lactone-type C19-diterpenoid alkaloids, rotundifosines A – C (1 - 3) along with two known diterpenoid alkaloids, heterophyllidine (4) and chellespontine (5) were isolated from the whole plant of Aconitum rotundifolium Kar. & Kir. Their structures were established on the basis of extensive spectroscopic analysis, including 1D and 2D NMR experiments. Compounds 13 were evaluated for cytotoxicity against MCF-7, MDA-MB-231, 786-0 and HepG2 human cancer cell lines.

Supporting Info. (1.2MB)PDF (399KB)

Published online: 9th August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13777
AgNTf2-Mediated Arylation of Bromopyrroloindolines

Soichiro Sato, Azusa Hirayama, Tohma Adachi, Daichi Kawauchi, Hirofumi Ueda, and Hidetoshi Tokuyama*

*Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan

Abstract

The silver(I)-mediated arylation of bromopyrroloindolines was developed. The selection of silver salts was crucial to obtain arylated compounds in high yields. Among the various tested silver(I) salts, AgNTf2 was the most effective agent for arylation. Reactions using various electron-rich aromatic compounds revealed that the developed conditions are suitable for the arylation of a broad range of aromatic compounds, including benzene derivatives, furan, thiophene, and pyrrole.

PDF (337KB)

Published online: 1st August, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13773
A Convenient Synthesis of Isotellurazoles via Deoxygenation of Isotellurazole Te-Oxide Oligomers by Using a Combination of Ph3P/I2

Yusuke Taneichi, Kazuaki Shimada,* and Toshinobu Korenaga

*Department of Chemistry and Biosciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan

Abstract

Ynones and ynals bearing a variety of substituent were converted into isotellurazole Te-oxide oligomers through a convenient procedure via formation and ring closure of β-(N,N-dimethylcarbamoyltellurenyl)alkenyl ketones or aldehydes, and the subsequent conversion of A into the corresponding isotellurazoles B was carried out efficiently by treating with Ph3P/I2 under a rather mild reaction condition.

Supporting Info. (4.7MB)PDF (248KB)

Published online: 27th July, 2017

Review | Regular issue | Prepress
DOI: 10.3987/REV-17-867
5-Aminotetrazole as a Building Block for Multicomponent Reactions (Review)

Anton V. Dolzhenko*

*School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia

Abstract

5-Aminotetrazole is a useful building block in organic synthesis, including various multicomponent reactions (MCRs). In MCRs, 5-aminotetrazole usually plays a role of 1,3-binucleophilic reagent, but in some reactions, the only reactive centre is an exocyclic amino group of 5-aminotetrazole. This review systematises MCRs involving 5-aminotetrazole forming a background for further investigations in this area.

PDF (1.1MB)

Published online: 24th July, 2017

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13694
Copper Accelerated One-Pot Sequential Tandem Synthesis of Tetrahydropurinoisoquinoline Derivatives

Pradip Kumar Maji* and Ayan Mahalanobish

*Department of Chemistry, Bidhan Chandra College , Asansol, Burdwan, 713304, WB, India

Abstract

Copper catalyzed efficient and operationally simple tandem synthesis of purino[8,9-a]isoquinolinedione from 5,6-diamino-1,3-dimethyluracil and in situ generated alkenyl aldehyde has been described. In this cascade reaction C-C and C-N bonds are formed through Sonogashira coupling, 5-endo cyclization, and 6-endo cyclization in a same reaction vessel.

Supporting Info. (3.2MB)PDF (311KB)
18 data found. 1 - 18 listed