HETEROCYCLES

■ Contents

■ Ring Opening Ring Closure Reactions with 3-Substituted Chromones under Nucleophilic Conditions

Magdy A. Ibrahim,* Nasser M. El-Gohary, and Sara Said

*Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo 11711, Egypt

Abstract

This review covers the ring opening ring closure (RORC) reactions of 3-substituted chromones with a variety of nitrogen and carbon nucleophiles. The nucleophilic reagent usually attack 3-substituted chromones at the C-2 position with γ-pyrone ring opening followed by further transformation during the course of the reaction producing a variety of products depending on the substrate at position 3, the nature of nucleophile and the reaction conditions.

■ Synthesis, Antimicrobial and Antihuman Liver Cancer Activities of Novel Sulfonamides Incorporating Benzofuran, Pyrazole, Pyrimidine, 1,4-Diazepine and Pyridine Moieties Prepared from (E)-4-(3-(Dimethylamino)acryloyl)-N-ethyl-N-methylbenzenesulfonamide

Sami A. Al-Harbi and Mahmoud S. Bashandy*

*Department of Chemistry, Al-Azhar University, Nasr City, Cairo 002, Egypt

Abstract

Reaction of compound 1 with dimethylformamide dimethylacetal gave enaminone 2, which reacts with 1,4-benzoquinone and 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one to afford 6 and 7, respectively. Treatment of 2 with hydroxylamine hydrochloride gave cyanoacetyl derivative 14. Enaminone 2 reacts with guanidine hydrochloride and phenylhydrazine to furnish 2-aminopyrimidine and pyrazole derivatives 15 and 16, respectively. Enaminone 2 also reacts with ethylenediamine and acetylacetone to afford the corresponding derivatives of 1,4-diazepine 18 and pyridine 20, respectively. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H NMR, 13C NMR and Ms spectral data. All the synthesized compounds were evaluated for antimicrobial activity. Compounds 6 and 20 were found to be highly active against the all microorganisms. In addition, all the compounds were tested in-vitro antihuman liver hepatocellular carcinoma cell line (HepG2). Compounds 14, 6, 18 and 16 with selectivity index (SI) values of 70.92, 55.56, 29.56 and 15.00, respectively, exhibited better activity than methotrexate (MTX) as a reference drug with SI value of 13.30. Virtual screening using molecular docking studies of the synthesized compounds was performed by Molecular Operating Environment (MOE). The results indicated that some synthesized compounds suitable inhibitor against dihydrofolate reductase (DHFR) enzyme (PDB ID: 4DFR) with further modification.

■ Four New Compounds from Pouzolzia zeylanica (L.) Benn. var. Microphylla

Chu-Qian Zhong, Shu-Hong Tao, Zhi-Bo Yi, Li-Bing Guo,* Yu-Feng Xie, and Yan-Fen Chen

*School of Traditional Chinese Medicine, Guangdong Pharmacutical University, University City, Waihuan Road 280#, Guangzhou, Guangdong, 510006, China

Abstract

Two new stilbenes, pouzolignan D (1) and K (2), and two new norlignans, pouzolignan L (3) and M (4), together with four known flavonoids, rhamnocitrin (5), rhamnetin (6), isorhamnetin (7) and quercetin(8), were isolated from the aerial parts of Pouzolzia zeylanica (L.) Benn. var. microphylla (Wedd.) W. T. Wang. Their structures were elucidated by spectroscopic methods, including UV, IR, HR-ESI-TOF-MS, 1D and 2D NMR experiments.

■ Synthesis, Characterization and Cytotoxicity Evaluation of Some Novel Pyrazole and Pyrrole Derivatives Containing Benzothiazole Moiety

Khaled S. Mohamed* and Ahmed A. Fadda

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

Abstract

The 1-(2-benzothiazolyl)-1-cyano-3-chloroacetone (1) was used as a key intermediate for the synthesis of pyrazole derivatives (3a-d) and pyrrole derivatives (5a-e) by its reaction with arylhydrazonomalononitrile and primary arylamines, respectively. Moreover, the reaction of 2-(benzo[d]thiazol-2-yl)-5-methyl-4-(pyridin-4-ylmethylene)-2,4-dihydro-3H-pyrazol-3-one (7) with a variety of reagents have been investigated aiming to explore its synthetic potentialities in synthesis of some novel pyrazole fused heterocyclic derivatives containing benzothiazole moiety. The structures of newly synthesized compounds have been established on the basis of their IR, 1H-NMR, 13C-NMR and mass spectral data. New compounds were tested for in vitro cytotoxicity against hepatocellular carcinoma (HepG-2) and breast cancer (MCF-7).

■ Efficient Microwave-Assisted Syntheses of A Series of Novel Mono(imino)pyrrolyl Compounds

Biyun Su,* Xiaoteng Li, Xudong Wang, and Qianding Li

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

Abstract

A series of novel mono(imino)pyrroles that were hard to prepare under traditional solvent reaction condition were readily synthesized under solvent free condition using microwave chemistry via p-TSA (p-toluenesulfonic acid) catalyzed Schiff base condensation. The structures of the compounds were characterized by means of MS, 1H NMR, IR, elementary analysis and X-ray diffraction analysis. The reactivity of different aromatic amines with 2-acetylpyrrole was discussed.

■ Nano-Copper Catalyzed Three-Component Tandem Cycloaddition and N-Alkylation Reaction from Aminophenylacetylenes, Sodium Azide and Alkyl Halides

Fangli Gang, Taosheng Dong, Guangli Xu, Ying Fu, and Zhengyin Du*

*College of Chemistry and Chemical Engineering, Northwest Normal University, Anning East Road, 967, 730070, China

Abstract

Nano-copper catalyzed one-pot three-component method is realized from aminophenylacetylenes, sodium azide and alkyl halides via tandem 3+2 dipolar cycloaddition reaction and N-alkylation reaction. This synthetic process gave the product of 1-alkyl-4-(N-alkylaminophenyl)-1,2,3-triazoles in good yields.

■ An Efficient Synthesis of Novel Dispiro Derivatives via Three-Component 1,3-Dipolar Cycloaddition Reactions under Ultrasound Irradiation

Chunling Shi* and Jun Zhou

*School of Chemistry and Chemical Engineering, Xuzhou Institute of Technology, Xuzhou City New Urban Area Lishui Road, 221111, China

Abstract

A series of new dispiro compounds were synthesized via the three-component 1,3-dipolar cycloaddition reaction of acenaphthenequinone, thiazolidine-4-carboxylic acid and (Z)-5-benzylidene-2-thioxothiazolidin-4-one or (Z)-5-benzylidenethiazolidine-2,4-dione in ethanol under ultrasound irradiation. This protocol has the advantages of mild reaction conditions, high yields and short reaction time.

■ Chromones from the Twigs of Cassia fistula and Their Anti-Tobacco Mosaic Virus Activities

Qiu-Fen Hu, Li-Mei Li, Dong-Lai Zhu, Zhen-Hua Yu, Jian-Bo Zhan, Jie Lou, Ye-De Wang, Kun Zhou, Min Zhou, Yin-Ke Li, and Xue-Mei Gao*

*Key Laboratory of Ethnic Medicine Resource Chemistry, State Ethnic Affairs Commission & Ministry of Education, School of Chemistry and Biotechnology, Yunnan University of Nationalities, Kunming, Jingming South Road, Chenggong New District, Kunming, Yunnan 650500, China

Abstract

Three new chromones, 2-(3-hydroxypropanoyl)-8-methoxy-5-(2-oxopropyl)-4H-chromen-4-one (1), 8-hydroxy-2-(3-hydroxypropanoyl)-5-(2-oxopropyl)-4H-chromen-4-one (2), 2-(2-hydroxyethyl)-7-methoxy-5-(2-oxopropyl)-4H-chromen-4-one (3), together with four known chromones (3-7) were isolated from the twigs of Cassia fistula. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1-3 were tested for their anti-tobacco mosaic virus (anti-TMV) activities. The results revealed that compound 1-3 showed high anti-TMV activities with inhibition rates of 26.6, 28.2 and 29.7%, respectively. These rates are close to that of positive control.

■ Chiral 9,9'-Binaphtho[2,3-b]furans

Peijun Ye, Qiuyun Li, Zhongsheng Bai, Kun Dong, and Qiancai Liu*

*School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China

Abstract

A series of novel difuro-fused binaphthalenes are reported. Synthetic methods include methylation, halogenation, Sonogashira coupling as well as base-mediated cyclization are employed to furnish the title compounds from chiral BINOL (R-BINOL and S-BINOL). The title compounds are confirmed by NMR spectra and mass spectra.

■ New Isocoumarins from the Fermentation Products of Entophytic Fungus Aspergillus versicolor and Their Anti-Tobacco Mosaic Virus Activities

Gang Du, Zhong-Cheng Wang, Ye-Kun Yang, Hong-Mei Yang, Hai-Ying Yang, Min Zhou, Yan-Qing Ye, Xue-Mei Li,* and Qiu-Fen Hu*

*Key Laboratory of Ethnic Medicine Resource Chemistry, State Ethnic Affairs Commission & Ministry of Education, School of Chemistry and Biotechnology, Yunnan University of Nationalities, Kunming, Jingming South Road, Chenggong New District, Kunming, Yunnan 650500, China

Abstract

Three new isochromenes, 6,7-dimethoxy-3-methyl-5-(3-methylbuten- 2-yl)-1H-isochromene (1), 7-methoxy-3-methyl-5-(3-methylbuten-2-yl)-1H- isochromen-6-ol (2), 3-methyl-5-(3-methylbuten-2-yl)-1H-isochromen-6-ol (3), together with three known isocoumarins (4-6) were isolated from the fermentation products of an endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of compounds 1-3 and 6 were evaluated. The results revealed that compounds 1-3 and 6 showed anti-TMV activity with inhibition rates of 26.8 and 25.4, 24.2 and 18.6% at the concentration of 20 μM, respectively.

■ Errata “Preparation and Antibacterial Evaluation of Some Symmetrical Twin-Drug Type Bivalent Molecules”: HETEROCYCLES, 2015, 91, 1676, DOI: 10.3987/COM-15-13263

Fumiko Fujisaki, Makoto Furutachi, Ryou Fujiwara, Miriko Okabe, Hatsumi Aki, Nobuhiro Kashige, Fumio Miake, and Kunihiro Sumoto*

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