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27 data found. 1 - 27 listed

Published online: 11th December, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-14001
Three New Chromone Derivatives from Cassia pumila and Their Anti-Tobacco Mosaic Virus Activity

Guang-Hui Kong, Yu-Ping Wu, Yin-Ke Li, Jing Li, Wei-Song Kong, Xin Liu, Yong Xu, Guang-Yu Yang, Qiu-Fen Hu,* and Wan-Li Zeng*

*Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission & Ministry of Education, Yunnan Minzu University, Kunming 650031, China

Abstract

Three new (1-3), together with four known chromone derivatives (4-7), were isolated from Cassia pumila. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1-3 were evaluated for their anti-tobacco mosaic virus (Anti-TMV) activity. The results showed that compounds 1-3 showed potential anti-TMV activities with inhibition rates of 28.3%, 31.2%, and 34.8%, at the concentration of 20 µM, respectively. These rates are close to that of positive control.

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Published online: 7th December, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13978
Facile and Solvent-Free Synthesis of Quinazolin-4(3H)-ones under Microwave Condition Promoted by SbCL3

Jun Li, Weili Wang,* Xinglin Su, Xiaoling Zhang, Yan Zhang, Xuewen Zhang, Mengmeng Cai, Yuqian Cao, Juan Jin, and Yanbin Xu*

*School of chemistry and material science, Ludong University, No. 186 Hongqi Middle Road, Zhifu District, 264025, China

Abstract

Antimony trichloride (SbCl3) was found to be an effective catalyst (1 mol%) for one-pot synthesis of quinazolin-4(3H)-ones in good to excellent yields using anthranilamide and acyl chlorides under microwave irradiation. This method has the advantages of simplicity, mild reaction conditions, highly tolerant to several functional groups, as well as the avoidance of hazardous solvents.

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Published online: 7th December, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-14003
Three New Limonoids from the Fruits of Melia toosendan

Qiong Zhang,* Min Li, Qing-Hong Zheng, and Zhi-Da Min

*Department of Pharmaceutical Science, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, Shanxi Province 030001, China

Abstract

Three new limonoids, 12-ethoxynimbolinins I-K (1-3), were isolated from the fruits of Melia toosendan. Their structures were established on the basis of spectroscopic methods. In addition, Compounds 1-3 were evaluated for their antibacterial activities.

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Published online: 7th December, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-14014
Brevisulcenal-G, -H, and –I, Polycyclic Ether Marine Toxins from the Dinoflagellate Karenia brevisulcata

Masayuki Satake,* Raku Irie, Yuka Hamamoto, Kazuo Tachibana, Patrick T. Holland, D. Tim Harwood, Feng Shi, Veronica Beuzenberg, Yoshiyuki Itoh, Fumiaki Hayashi, and Huiping Zhang

*Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Abstract

Members of two classes of marine polycyclic ether compounds, brevisulcenals (KBTs) and brevisulcatic acids (BSXs), were isolated as causative toxins from a red tide (Karenia brevisulcata) bloom event in New Zealand in 1998. The new analogues, brevisulcenals (KBTs)-G, -H, and -I, were isolated from neutral lipophilic extracts of bulk dinoflagellate culture extracts, and the molecular structures of these compounds were elucidated by detailed analyses of NMR and matrix-assisted laser desorption/ionization tandem mass spectrometry spectra, and by comparison with the spectra of KBT-F. All the analogues have the same size and arrangement of 24 ether rings, but differ in their backbone substitution patterns and degree of terminal oxidation. The cytotoxicity of these new KBT analogues was greater than that of the co-isolated, KBT-F.

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Published online: 29th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13993
Synthesis of Imidazolium Salts Bearing Two Cyclodextrins

Susumu Tsuda,* Yohei Minami, Ryoji Ueda, Takanori Iwasaki, Shin-ichi Fujiwara, Hitoshi Kuniyasu, and Nobuaki Kambe*

*Depertment of Chemistry, Faculty of Dentistry, Osaka Dental University, 8-1 Kuzuhahanazono-cho, Hirakata, Osaka 573-1121, Japan

Abstract

Cyclodextrin (CD) homo and hetero dimers including an imidazolium salt were prepared from imidazolyl CDs and the corresponding CD monotosylates. The CD dimer imidazolium salts were characterized by MALDI-TOF mass and NMR spectroscopies.

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Published online: 20th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13955
Synhesis, Molecular Docking Studies and in vitro Antimicrobial Evaluation of Novel Pyrimido[1,2-a]quinoxaline and Triazino[4,3-a]quinoxaline Derivatives

Rania B. Bakr,* Nadia A. A. Elkanzi , Amira A. Ghoneim, and Shaima M. N. Moustafa

*Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt

Abstract

A series of 3-substituted-2,6-dihydro-1H-pyrimido[1,2-a]quinoxaline- 5-carboxylates (4a,b), (8c,d) and (13a,b) were prepared by treating ethyl 3-amino-1,4-dihydroquinoxaline-2-carboxylate (1) with alkylidenemalononitrile derivatives. Moreover, 8H-benzo[5,6][1,2,4]triazino[4,3-a]quinoxaline-7-carboxylate derivatives (18, 20, 22, 24) were synthesized from condensation reaction between diazonium salts 16 with resorcinol, 1-naphthol, malononitrile and ethyl acetoacetate respectively. Some of the newly synthesized compounds were screened for their antimicrobial activity studies. Furthermore, molecular docking were performed on the active compounds 1, 4a and 8c to predict the mode of action of these novel compounds.

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Published online: 20th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13990
An Efficient Synthesis and Evaluation of Antitumor Activities of Functionalized Pyrano[2,3-b]quinolines

Wei Lin, Mengye Zhang, Ning Wang, Wentao Xu, and Daqing Shi*

*Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, Jiangsu, China

Abstract

An efficient synthesis of novel functionalized pyrano[2,3-b]quinoline derivatives via a three-component reaction of 2-chloroquinoline-3-carbaldehydes, malononitrile and 1,3-dicarbonyl compounds under microwave irradiation is described. This protocol has the advantages of high efficiency, mild reaction conditions, a one-pot procedure, and convenient operation. All of these compounds were evaluated for their antiproliferative properties in vitro against hepatic carcinoma cells and several compounds were found to have good activities.

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Published online: 19th November, 2018

Communication | Regular issue | Prepress
DOI: 10.3987/COM-18-13988
New Facile Synthesis of 3-Substituted 7,8-Dihydroquinolin-5(6H)-ones and [1]Benzopyrano[4,3-b]pyridin-5-ones Using 2-(Hetero)arylvinamidinium Salts

Yiyi Weng, Chen Sun, Qingwei Cao, Hantao Chen, Nanhui Li, Zhuo Chen, and Weike Su*

*Collaborative Innovation Center of Yangtze River Delta Region Green of Pharmaceuticals, Zhejiang University of Technology, Hangzhou 310014, China

Abstract

The method of cyclocondensation of 3-amino-2-cyclohexen-1-ones 2 or 4-aminocoumarin 3 with symmetrical 2-(hetero)aryl-vinamidinium salts 1 has been developed, providing an efficient synthetic pathway to access novel functionalized 3-substituted 7,8-dihydroquinolin-5(6H)-ones 4 or [1]benzopyrano[4,3-b]pyridin-5-ones 5 in good to excellent yields. All the aryl-substituted and heterocyclic-substituted vinamidinium salts undergo a facile electrocyclic ring closure to form pyridine ring with α,β-unsaturated ketones. A possible mechanism for the formation of pyridine ring is proposed.

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Published online: 15th November, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13969
Synthesis, Characterization and Antimicrobial Evaluation of Some Novel Fused Pyrimido[1,2-b][1,2,4]triazine, Triazino[2,3-a]quinazoline and Imidazo[1,2-b][1,2,4]triazine Derivatives

Khaled S. Mohamed* and Elsherbiny H. El-Sayed

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

Abstract

A novel pyrimido[1,2-b][1,2,4]triazine derivatives were synthesized by allowing 3-amino-1,2,4-triazine (1) to react with different reagents such as enaminone, enaminonitriles, 3-bromopropanenitile, 2-(2,5-dimethoxybenzylidene)malononitrile and 1,3-dicarbonyl compounds. Moreover, triazino[2,3-a]quinazoline derivatives were synthesized by reaction of 1 with 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (18) and 2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one (20). On the other hand, treatment of 1 with 2-bromo-1-(naphtho[2,1-b]furan-2-yl)ethan-1-one (22) afforded imidazo[1,2-b][1,2,4]triazine derivative (23). The newly synthesized compounds were evaluated for their antimicrobial activities based on inhibition diameter zone against Gram positive and Gram negative bacteria.

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Published online: 15th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13991
A Pair of New Non-glycosidic Iridoid Epimers from Scrophularia ningpoensis

Wei Zhang, Peng Liu, Xin-Yu Ji, Xiang-Yang Chen, Yan-Yan Jiang, and Bin Liu*

*School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China

Abstract

A pair of new non-glycosidic iridoid epimers, ningpogenins A and B (1a/1b), together with eighteen known ones (2-19) were isolated from the roots of Scrophularia ningpoensis. Their structures were elucidated by spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS. Compound 1 is an unusual example of natural ningpogenin—L-pyroglutamic adducts. In addition, the cytotoxic effects of the new compound against HepG2, U251 and SH-SY5Y cell lines were evaluated.

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Published online: 14th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13981
New Prenylated Bibenzyls from Bornean Liverwort Acrobolbus saccatus

Shean-Yeaw Ng, Takashi Kamada, Chin-Soon Phan, Monica Suleiman, and Charles S. Vairappan*

*Laboratory of Natural Products Chemistry, Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia

Abstract

Liverworts are the most primitive terrestrial plant which known to produce unique and wide variety of compounds. Ethyl acetate crude extract was subjected to several chromatographic techniques for purification. Three new compounds, saccatenes A-C (1-3) were isolated together with two known prenyl bibenzyl derivative, 2,2-dimethyl-5-hydroxy-6-carboxy-7-(2-phenylethyl) chromene (4) and radulanin A-5-one (5) from the Bornean liverwort Acrobolbus saccatus (Hook.) Trevis collected from Mountain Trus Madi, Sabah, Malaysia. The structures of the three new metabolites were established by analyses of the spectroscopic data (1D NMR, 2D NMR, HRESIMS and IR), and the antibacterial activity against eight selected human pathogenic species of bacteria were tested.

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Published online: 14th November, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13984
Utilization of Chlobenthiazone and Benazolin-ethyl as 4-Substituted 2(3H)-Benzothiazol-2-one Scaffolds

Masatoshi Kakuno, Shotaro Izawa, Taichi Takemoto, and Yoo Tanabe*

*Department of Chemistry, School of Scienece and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan

Abstract

N(3)-Substituted 4-aryl (or heteroaryl)-2(3H)-benzothiazol-2-ones were synthesized from readily accessible chlobenthiazone and benazolin-ethyl, a couple of N(3)-substituted 4-chloro-2(3H)-benzothiazol-2-one pesticides, utilizing Suzuki-Miyaura cross-coupling reactions (9 examples; 44–98% yield), although with less reactive stereocongested 4-chloro pendant substituent. In a similar fashion, N(3)-substituted 4-anilino (or BocNH)-2(3H)-benzothiazol-2-ones were synthesized from the 4-bromo analogues of the chlobenthiazone-utilizing Buchwald-Hartwig cross-coupling reactions (3 examples; 50–89% yield). In addition, a short synthesis of the key chloro-type quinone segment in natural mevashuntin with a unique 2(3H)-benzothiazol-2-one skeleton, was performed in three short steps with 61% overall yield. The obtained quinone segment functioned as a Diels-Alder reaction dienophile toward the Danishefsky-Kitahara diene as the model experiment. All schemes utilized a common cyclo-condensation using chlorocarbonylsulfenyl chloride for the construction of 4(ortho)-substituted 2(3H)-benzothiazol-2-one substrates.

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Published online: 9th November, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13980
Effect of meta-Substituents on the Radical Scavenging Activity of 6-Chromanol Derivatives

Keiko Inami,* Yuta Okayama, Mariko Suzuki, and Masataka Mochizuki

*Division of Pharmaceutical Organic Chemistry, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda-shi, Yamaguchi 756-0884, Japan

Abstract

A series of 8-substituted 6-chromanols, namely, the methyl- (4), methoxy- (5), amino- (6), methylamino- (7), dimethylamino- (8), 1-pyrrolidinyl- (9), piperidino- (10), 1-piperazinyl- (11), and morpholino- (12) derivatives, were synthesized and investigated to determine the effect of substitution meta to the phenolic OH group of a 6-chromanol on the radical scavenging activity. 7 and 9 possessed excellent radical scavenging properties. Our data showed that the lone-pair electrons on the nitrogen atom of the substituent at the m-position donated electron density into the conjugated p-orbitals on the 6-chromanoxyl radical by δ-donation through resonance, enhancing the radical scavenging activity.

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Published online: 5th November, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13995
Synthesis of 4H-1,3,2-Benzodithiazin-4-imine 1,1-Dioxide Derivatives by Oxidative Cyclization of 2-(Aminosulfonyl)benzothioamide Derivatives with Iodine

Kazuhiro Kobayashi* and Daiki Fujiwara

*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

An efficient method for the construction of the 4H-1,3,2-benzodithiazine structure utilizing facile experimental operations from readily available starting materials is described. 2-Substituted (Z)-N-alkyl-4H-1,3,2-benzodithiazin-4-imine 1,1-dioxides can be obtained by the treatment of 2-(aminosulfonyl)benzothioamides, derived from the reaction between 2,N-dilithio derivatives of secondary benzenesulfonamides and isothiocyanates, with iodine in the presence of two equivalents of triethylamine.

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Published online: 26th October, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13957
Microwave Promoted Diels-Alder Reaction of 1,2-Dihydropyridine

Stephen R. Slauson,* Natalia Echeverry, Samantha Copeland, Alessandra Stoj, Melissa A. Kemp, and Maria Simon

*Department of Pharmaceutical Sciences, School of Pharmacy, University of Saint Joseph, 229 Trumbull Street, Hartford, CT 06103, U.S.A.

Abstract

The microwave-assisted Diels-Alder reaction between 1,2-dihydropyridine and activated dienophiles is reported. The conditions facilitate the production of the [2.2.2] scaffold in high yields with simple purification.

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Published online: 22nd October, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13974
HBr-Promoted Sulfenylation of Pyrazolones and 4-Hydroxycoumarins with N-(Organothio)succinimides

Hongai Jin, Wangyang Wang, Zhaohua Yan,* Rongxing Zhang, Mingchuang He, and Sen Lin*

*College of Chemistry, Nanchang University, No. 999, Xuefu Rd. 330031, China

Abstract

A convenient, effective and metal-free method for the synthesis of C-4 sulfenylated pyrazolones via HBr-promoted sulfenylation of pyrazolones with N-(organothio)succinimides as sulfur sources was developed. The method can be extended to apply for substrates 4-hydroxycoumarins. A series of C-4 sulfenylated pyrazolones and C-3 sulfenylated 4-hydroxycoumarins were smootly synthesized in good to excellent yields.

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Published online: 19th October, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13983
One-Pot Synthesis of 6H-Indolo[2,3-b]quinolines from 2-Nitrobenzaldehyde and Indole Derivatives via Domino Reaction

Wei-Nan Zhang, Jiao Xu,* Dao-Lin Wang,* and Zhen-Kai Zhong

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

Abstract

An efficient and simple method for the synthesis of 6H-indolo[2,3-b]- quinolones was described. The construction of this fused heterocycles system was achieved by alkylation–reduction–cyclization domino reaction of 2-nitro- benzaldehyde with indoles using SnCl2 as a promoter in [bmim]Br medium.

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Published online: 18th October, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13986
Synthesis of 4-Arylisoquinoline-1(2H)-thione Derivatives by Sodium Hydride-Mediated Cyclizations of 2-(1-Arylethenyl)benzothioamides

Kazuhiro Kobayashi* and Takuma Ueyama

*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 new and facile method for the general preparation of isoquinoline-1(2H)-thione derivatives has been developed. Thus, the sodium hydride-mediated cyclization of N-substituted 2-(1-arylethenyl)benzothioamides, which are derived from the reaction of 2-(1-arylethenyl)phenyllithiums with isothiocyanates, gives 2-substituted 4-aryl-3,4-dihydroisoquinoline-1(2H)-thiones. In addition, the use of N-substituted 2-(1-aryl-2-methoxyethenyl)benzothioamides from 2-(1-aryl-2-methoxyethenyl)phenyllithiums and isothiocyanates affording 2-substituted 4-arylisoquinoline-1(2H)-thiones is described.

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Published online: 15th October, 2018

Review | Regular issue | Prepress
DOI: 10.3987/REV-18-892
The Dawn, Evolution and Personal Reminiscences in Studies of Glycosyl Isocyanates and Isocyanides

Yoshiyasu Ichikawa*

*Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan

Abstract

Historical background and personal reflections on my research career studying glycosyl isocyanates and isocyanides are described

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Published online: 15th October, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13977
Biginelli Reaction of Aliphatic Aldehydes Catalyzed by α-Chymotrypsin: One-Pot Biocatalytic Synthesis of Dihydropyrimidinones

Lei-Han Fu, Zong-Bo Xie,* Jin Lan, Hong-Xia Li, Lian-Sheng Liu, and Zhang-Gao Le*

*Department of Applied Chemistry, East China University of Technology, Guanglan Road 330013, China

Abstract

A green and highly efficient procedure was developed for the one-pot, three-component synthesis of 3,4-dihydropyrimidin-2-(1H)-ones by the condensation of aliphatic aldehydes, β-keto esters, and urea. α-Chymotrypsin from porcine pancreas showed excellent catalytic activity in the reaction. The influences of solvents, temperature, and water content were investigated. The desired products were obtained in 85-96% yields. The methodology generates high yields with a wide range of substrates.

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Published online: 10th October, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13967
A New HBT-Based Fluorescent Probe for Hydrazine Detection in Aqueous Solution

Jing-Hua Dong,* Jia Deng, and Yuan Zhang

*Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, 11, Cihu Road, Huangshi, Hubei Province 435002, China

Abstract

A new HBT-based fluorescent probe is designed and synthesized for the detection of hydrazine based on Gabriel-type hydrazinolysis reaction mechanism. The probe responds selectively to hydrazine with obvious turn-on fluorescence. The water sample analysis indicated its great potential in the environment monitoring of hydrazine in aqueous solution.

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Published online: 10th October, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13972
Vanadium-Catalyzed Achmatowicz and Aza-Achmatowicz Rearrangement Reactions

Wang-Ze Song,* Nan Zheng, Ming Li, Karim Ullah, Jun-Hao Li, Kun Dong, and Yu-Bin Zheng*

*School of Pharmaceutical Science and Technology, Dalian University of Technology, No.2 Linggong Road, Ganjingzi District, Dalian City, Liaoning Province 116024, China

Abstract

A novel and efficient synthesis of substituted pyranones and pyridinones is developed using cumene hydroperoxide as oxidant by vanadium-catalyzed Achmatowicz rearrangement and aza-Achmatowicz rearrangement reactions. It offers a sustainable and environmentally benign approach to access multisubstituted pyranones or pyridinones derivatives.

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Published online: 28th September, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13968
One-Pot Synthesis of Isoindolin-1-ones from Nitroarenes and o-Phthalaldehyde via Indium-Mediated Reductive Condensation Reactions

Eungyung Kim, Mingyeong Jeong, Byung Min Lee, and Byeong Hyo Kim*

*Department of Chemistry, Kwangwoon University, 447-1, Wolgye-Dong Nowon-ku, Seoul, 139-701, Korea

Abstract

Indium-mediated reductive condensation reactions of various nitroarenes with o-phthalaldehyde toward isoindolin-1-ones were investigated. In the presence of indium/AcOH in toluene at reflux, nitroarenes were coupled and cyclized with o-phthalaldehyde to produce corresponding isoindolin-1-ones with reasonable yields.

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Published online: 26th September, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13965
Protein-Promoted Synthesis of Chromene Derivatives via Biocatalytic Domino Reaction

Long-Hua Zhou,* Wei-Hua Huang, Li-Fang Ma, Yong-Jiu Jin, Fang Chen, and Yu-Ling Zhu

*Physical and Chemical Department, Nanchang Centre for Disease Control and Prevention, Lijing Road 833, Honggutan, Nanchang, 330038, China

Abstract

An efficient and green procedure has been developed for the synthesis of chromenes using 1,3-diketones and ɑ,β-unsaturated aldehydes. The effect of reaction conditions including solvents, water content, molar ratio of substrates and catalyst loading were investigated. A series of chromene derivatives were prepared with moderate to high yields under the catalysis of bovine serum albumin (BSA) in isopropanol successfully. This novel activity of BSA to catalyze the domino reaction is not only of practical significance in expanding the application of biocatalysts, but also providing more convenient synthetic method for green chemistry.

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Published online: 26th September, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-18-13966
One-Pot Synthesis of 3-Oxo-2H,4H-1,4-benzothiazine-2-carbonitrile Derivatives via Cyclization of Methyl {[2-(Cyanomethyl)sulfanyl]phenyl}carbamate

Kazuhiro Kobayashi,* Kazuki Kawano, and Daiki Fujiwara

*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 synthesis of 3-oxo-2H,4H-1,4-benzothiazine-2-carbonitrile (2-cyano-2H-1,4-benzothiazin-3(4H)-one) derivatives has been developed. Sodium hydride-mediated cyclization of methyl {[2-(cyanomethyl)sulfanyl]phenyl}carbamate, which can be easily prepared from commercially available 2-aminobenzenethiol in two steps, allows the synthesis of 3-oxo-2H,4H-1,4-benzothiazine-2-carbonitrile and its 2-mono- and 2,4-di- alkylated derivatives in one-pot.

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Published online: 19th September, 2018

Review | Regular issue | Prepress
DOI: 10.3987/REV-18-893
Synthesis, Reaction and Biological Activity of Pyrazolo[5,1-c][1,2,4]benzotriazine 5-Oxides

Ghodsi Mohammadi Ziarani,* Manizheh Mostofi, Negar Lashgari,* and Mohammad Mahdavi

*Department of Chemistry, Alzahra University, Tehran, Iran

Abstract

[1,2,4]Benzotriazine fused to pyrazole ring is a privileged heterocyclic scaffold present in numerous pharmacologically active compounds. Till date, various pyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides and their deoxy analogues, possessing a broad spectrum of potent pharmacological activities, have been reported. In this review, we highlighted synthesis, chemical reactions, medicinal chemistry aspects and applications of fused pyrazole derivatives of [1,2,4]benzotriazine analogues reported so far.

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Published online: 5th September, 2018

Review | Regular issue | Prepress
DOI: 10.3987/REV-18-894
Tetrazole-Fragmentation for the Generation of Alkylidene Carbenes from Cyanophosphates under Neutral Conditions and Its Application to Organic Synthesis

Hiroki Yoneyama and Shinya Harusawa*

*Laboratory of Pharmaceutical Organic Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan

Abstract

The generation of alkylidene carbenes through tetrazole-fragmentation from cyanophosphates (CPs) under neutral conditions and its application to organic synthesis are reviewed. The following topics are covered: 1) The formation of α-azidotetrazoles and their transformation into alkynes under microwave heating conditions, 2) the transformation of carbonyl compounds into homologous alkynes via CPs, 3) the synthesis of five-membered unsaturated cyclic compounds from ketones via CPs, 4) the synthesis of C4-linked Cn-triazole ribonucleoside phosphoramidites from β-ribofuranosyl-Cn-acetylenes, and 5) the synthesis of (_)-neplanocin A and one of its important synthetic intermediates using cyclopentene-formation from CPs.

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27 data found. 1 - 27 listed