- A Novel and Convenient Mercury(II) Mediated Synthesis of Chroman-4-ones
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A simple route to chroman-4-ones from γ-bromopropynyl aryl ethers (1) using mercury(II) trifluoroacetate as a catalyst is described.
- Gopalsamy, Ariamala,Balasubramanian, K. K.
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- Acid activated montmorillonite K-10 mediated intramolecular acylation: Simple and convenient synthesis of 4-chromanones
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3-Aryloxyproionic acids undergo intramolecular cyclization in the presence of AA.Mont.K-10 in toluene under reflux for 30–45 min in good to excellent yields. Phenyl ring bearing various substituents at the ortho, meta, para positions undergo this cyclization reaction. This method involves simple work up and amenable for large scale preparations. The heterogeneous acid treated catalyst can be regenerated and used for up to three cycles with minimum loss of activity.
- Begum, Ayisha F.,Balasubramanian, Kalpattu K.,Shanmugasundaram, Bhagavathy
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supporting information
(2021/09/13)
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- Synthesis and antimicrobial activity of 2-(4-phenyl-2h-chromen-3-yl)-1h-benzo[d]imidazole
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A new series of 4-phenyl-2H-chromene-3-benzimidazoles (8a-o) were synthesized by the condensation of 4-phenyl-2H-chromene-3- carbaldehyde with o-phenylene diamines. The products were purified through column chromatography and structures of these compounds were characterized by IR, 1H & 13C NMR and mass spectral data. All the final compounds were screened for their antimicrobial activity and their efficacy were matched with ciprofloxacin. Five compounds (8b, 8d, 8i, 8l and 8o) were found to be most effective compounds of this series and with activities improved than ciprofloxacin under the tested conditions.
- DASARI, RAMACHANDRAIAH,THALARI, GANGADHAR,YERRABELLY, JAYAPRAKASH RAO,CHITNENI, PRASAD RAO
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p. 1723 - 1728
(2021/07/31)
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- Design, Synthesis, and Antimicrobial Activity of (E)-4-Phenyl-2H-chromene-3-carbaldehyde O-[(1-Phenyl-1H-1,2,3-triazol-4-yl)methyl]oxime Derivatives
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Abstract: A new series of 1,4-disubstituted 1,2,3-triazole derivatives tethered to a2H-chromene scaffold have beensynthesized via a click reaction. The synthesized chromene–triazole conjugateswere screened for their antibacterial activity against E. coli, S. aureus, P. aeruginosa and B.subtilis, as well as for antifungal activity against A. niger and C. albicans. Among the 17 synthesized compounds, 6 derivativesshowed the best antimicrobial activity. Molecular docking studies of the titlecompounds with carotenoid dehydrosqualene synthase (PDB: 2ZCS) revealed dockingscores within the range 98.241–91.488 against 106.573 for the reference ligandCiprofloxacin and with lanosterol 14α-demethylase (CYP51; PDB ID: 5V5Z),103.672–96.917 against 110.839 for the reference ligand Voriconazole.
- Chittneni, P. Rao,Dasari, R.,Thalari, G.,Yerrabelly, J. Rao
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p. 1519 - 1532
(2021/10/26)
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- Synthesis and anti-inflammatory activity of 2-oxo-2H-chromenyl and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates
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Cycloaddition reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehydes (3a-g) and 4-chloro-2H-chromene-3-carbaldehydes (7a-h) with activated alkynes (4a-b) provided the 2-oxo-2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (5a-n) and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (8a-p). All the prepared compounds were screened for anti-inflammatory activity. In vitro anti-inflammatory activity data demonstrated that the compounds 5g, 5i, 5k-l and 8f are effective among the tested compounds against TNF-α (1.108 ± 0.002, 0.423 ± 0.022, 0.047 ± 0.001, 0.070 ± 0.002 and 0.142 ± 0.001 μM) in comparison with standard compound Prednisolone (0.033 ± 0.002 μM). Based on in vitro results, three compounds (5i, 5k and 8f) have been selected for in vivo experiments and these compounds are identified as better compounds with respect to anti-inflammatory activity in LPS induced mice model. Compound 5i was identified as potent and showed significant reduction in TNF-α and IL-6.
- Bhimapaka, China Raju,Karri, Shailaja,Kuncha, Madhusudana,Kurma, Siva Hariprasad,Sistla, Ramakrishna
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- Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- And α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
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The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies revealed that hexafluoro-2-propanol also served as a hydrogen source in the process.
- Zhan, Xiao-Yu,Zhang, Hua,Dong, Yu,Yang, Jian,He, Shuai,Shi, Zhi-Chuan,Tang, Lei,Wang, Ji-Yu
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p. 6578 - 6592
(2020/07/17)
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- Facile access to chiral 4-substituted chromanes through Rh-catalyzed asymmetric hydrogenation
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Rh/ZhaoPhos-catalyzed asymmetric hydrogenation of a series of (E)-2-(chroman-4-ylidene)acetates was successfully developed to prepare various chiral 4-substituted chromanes with high yields and excellent enantioselectivities (up to 99percent yield, 98percent ee). Moreover, the gram-scale hydrogenation could be performed well in the presence of 0.02 molpercent catalyst loading (TON = 5000), the hydrogenation product was easily converted to access other important compounds, which demonstrated the synthetic utility of this asymmetric catalytic methodology.
- Tao, Lin,Zhao, Qingyang,Zhang, Xumu,Dong, Xiu-Qin
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p. 1859 - 1862
(2020/01/21)
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- Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
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A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92percent.
- Cho, Yang Yil,Jang, Hyu Jeong,Kim, Dong Hwan,Kim, Nam Yong,Kim, Nam-Jung,Kim, Young Min,Lee, Soo Jin,Lee, Yong Sup,Park, Boyoung Y.,Son, Seung Hwan,Yoo, Hyung-Seok
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supporting information
p. 10012 - 10023
(2019/08/30)
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- Hydrated ferric sulfate-catalyzed reactions of indole with aldehydes, ketones, cyclic ketones, and chromanones: Synthesis of bisindoles and trisindoles
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Hydrated ferric sulfate [Fe2(SO4)3·xH2O] has been found to be an efficient catalyst for condensation of bisindoles or trisindoles with aliphatic or aryl aldehydes and ketones including methyl and ethyl-alkyl ketones, methyl aryl ketones, cyclic ketones, and 4-chromanones in 19–96% yields. Trisindoles and 2,2'-alkylidenebisindoles were obtained from indole-3-carbaldehydes or 3-methylindole in 72–84% yields. A total of 43 substrates was employed, giving 33 bisindoles, 3 trisindoles, and one 2:2 product; seventeen of these are new. The best results were obtained from heating ethanolic suspensions, with Fe2(SO4)3·xH2O loaded at 60 mg per mmol of electrophiles. The reaction times were typically 1–4 h, while hindered electrophiles required 8–24 h. These conditions were strong enough to promote 2:1 condensation of indole with substrates without forming higher-order byproducts, with few exceptions. This strategy features tolerance by the catalyst of a wide range of functional groups, readily available starting materials, simple operation, mild reaction conditions, and is environmentally friendly.
- Noland, Wayland E.,Kumar, Honnaiah Vijay,Flick, Grant C.,Aspros, Cole L.,Yoon, Jong Hyeon,Wilt, Andre C.,Dehkordi, Nasim,Thao, Sheng,Schneerer, Andrew K.,Gao, Siming,Tritch, Kenneth J.
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p. 3913 - 3922
(2017/06/13)
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- Synthesis, characterization, and antimicrobial activity of novel substituted 2H-chromenyl acrylates
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The present study deals with conventional Witting olefination of 2H-chromene-3-carbaldehydes with stabilized ylide in the presence of dichloromethane to afford (2E)-ethyl-3-(4-chloro-2H-chromen-3-yl) acrylate derivatives. All the products were found to have E-geometry at C=C bond. The synthesized compounds were characterized by spectral data such as IR, 1H NMR and MS. Compounds were screened for antimicrobial activity against strains of gram positive, gram negative bacterial and fungal strains. All compounds showed good antibacterial and antifungal activity.
- Subhashini,Ravi,Cherupally,China Raju,Reddy,Bee
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p. 2900 - 2905
(2017/03/22)
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- N-Aryl-N'-(chroman-4-yl)ureas and thioureas display in vitro anticancer activity and selectivity on apoptosis-resistant glioblastoma cells: Screening, synthesis of simplified derivatives, and structure-activity relationship analysis
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A series of chroman derivatives previously reported as potassium channel openers, as well as some newly synthesized simplified structures, were examined for their in vitro effects on the growth of three human high-grade glioma cell lines: U373, T98G, and Hs683. Significant in vitro growth inhibitory activity was observed with 2,2-dimethylchroman-type nitro-substituted phenylthioureas, such as compounds 4o and 4p. Interestingly, most tested phenylureas were found to be slightly less active, but more cell selective (normal versus tumor glial cells, such as 3d, 3e, and 3g), thus less toxic, than the corresponding phenylthioureas. No significant differences were observed in terms of chroman-derivative-induced growth inhibitory effects between glioma cells sensitive to pro-apoptotic stimuli (Hs683 glioma cells) and glioma cells associated with various levels of resistance to pro-apoptotic stimuli (U373 and T98G glioma cells), a feature that suggests non-apoptotic-mediated growth inhibition. Flow cytometry analyses confirmed the absence of pro-apoptotic effects for phenylthioureas and phenylureas when analyzed in U373 glioma cells and demonstrated U373 cell cycle arrest in the G0/G1 phase. Computer-assisted phase-contrast videomicroscopy revealed that 3d and 3g displayed cytostatic effects, while 3e displayed cytotoxic ones. As a result, this work identified phenylurea-type 2,2-dimethylchromans as a new class of antitumor agents to be further explored for an innovative therapeutic approach for high-grade glioma and/or for a possible new mechanism of action.
- Goffin, Eric,Lamoral-Theys, Delphine,Tajeddine, Nicolas,De Tullio, Pascal,Mondin, Ludivine,Lefranc, Florence,Gailly, Philippe,Rogister, Bernard,Kiss, Robert,Pirotte, Bernard
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experimental part
p. 834 - 844
(2012/09/11)
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- Design and synthesis of α,β-epoxyketones as new anticancer agents
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As epoxy functional group has high anticancer activity, α,β-epoxyketones were designed and synthesized as new anticancer agents, and their structures were confirmed by UV, 1H NMR, IR, MS technigeces and elemental analysis. Their in vitro anticancer activities were evaluated by MTT method and the results showed that the compound 4c exhibited good activity with IC50 of 17.8, 22.0 and 24.1 μg/mL against A-549, Hela and HepG2 cells, respectively. The dose of LD50 of the mice by intragastric administration was 1864.4 mg/kg. Therefore, the α,β-epoxyketones could potentially provide as new anticancer agents. A series of α,β-epoxyketones were synthesized in a four steps reaction and tested for their anticancer activities.
- Ma, Zhengyue,Zhang, Xinghua,Wang, Shikui,He, Yang,Yang, Gengliang,Li, Beilei,Yang, Junjie,Lu, Yuejuan,Sun, Jiewei
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scheme or table
p. 757 - 764
(2011/11/12)
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- Chroman Compound, Processes for Its Preparation, and Its Pharmaceutical Use
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The present invention provided a chroman compound, the method of its preparation and pharmaceutical applications. The compound are represented by formula (I) and its pharmaceutical salt, where in :x is for O or S; n is for 2, 3 or 4; R1 is 6-situ or 7-situ halogen, C1-4alkyl, C1-4alkyoxyl, benzyloxy, acylamino; R2 is nitrogen-containing pentatomic or hexahydric substituted heterocyclic ring. The compound is useful to prepare anti-arrhythmic drugs, the reaction conditions of the method are mild, the raw material are plenty and easy to be obtained, and the operation and post-treatment are simple.
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Page/Page column 6
(2008/06/13)
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- Preparation of 6-substituted 4-chromanones
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Disclosed is a practical and efficient process for preparing 6-substituted 4-chromanones from phenolic acrylate ester compounds derivable from para-substituted phenolic or thiophenolic compounds and beta-unsubstituted acrylic acid compounds which are esterifiable therewith. The process includes effecting rearrangement of a phenolic or thiophenolic acrylate ester in the presence of a rearrangement effective amount of hydrogen fluoride to the corresponding hydroxy - or mercapto (vinyl ketone) wherein the carbonyl carbon atom of the vinyl carboxy group is directly attached to the benzene ring ortho to the hydroxy or mercapto group. Thereafter, the vinyl ketone is cyclized to the corresponding 6-substituted 4-chromanone in the presence of a cyclization-effective amount of hydrogen fluoride. The 6-substituted 4-chromanones prepared by the process are useful as intermediates for preparing pharmaceutical agents.
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- THERMAL BEHAVIOUR OF ARYL γ-HALOPROPARGYL ETHERS
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A systematic study of the behaviour of aryl γ-halopropargyl ethers under thermal condition was undertaken.Aryl γ-bromopropargyl ethers 2 underwent unique transformation in N,N-diethylaniline (215 deg C, 6 h) giving rise to a mixture of products 3,4 and 5,whereas, under similar conditions aryl γ-chloropropargyl ethers 8, afforded 4-chlorochromenes, 9.A remarkable substituent and solvent effect has been observed in the thermolysis of these aryl γ-bromo and γ-chloropropargyl ethers, rendering this transformation as a method for the synthesis of a number of substituted 4-bromochromenes 3, 4-chlorochromenes 9 and chroman-4-ones 7.In contrast, solution thermolysis of aryl γ-iodopropargyl ether 11 afforded aryl propargyl ether 1 as the major product.
- Ariamala, G.,Balasubramanian, K. K.
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p. 309 - 318
(2007/10/02)
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- Photochromic spiropyran compounds
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A series of novel photochromic spiropyrans are disclosed in which a spiro-adamantane group is introduced into the 2-position of the benzopyran or naphthopyran ring. The spiropyran compounds of the invention exhibit heliochromic properties, i.e. they color in sunlight and fade rapidly at ambient temperatures in the absence of U.V. light, making them good candidates for use in the manufacture of sunglasses. The invention includes lenses which darken in sunlight and incorporate the novel spiropyrans and a process for the preparation of the spiropyran compounds.
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- A Modified Synthesis of 4-Chromanones
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Problems in the synthesis of 4-chromanones by condensation of 2-hydroxyacetophenones with formaldehyde can be avoided by the isolation of the Mannich base hydrochlorides and cyclization by titration with potassium hydroxide.
- Cox, Brian,Waigh, Roger D.
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p. 709 - 710
(2007/10/02)
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- A SIMPLE ROUTE FOR THE SYNTHESIS OF 4-CHLOROCHROMENES AND CHROMAN-4-ONES
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A one pot synthesis of a number of 4-chlorochromenes and chroman-4-ones was achived from γ-chloropropargyl aryl ethers proceeding through Claisen rearrangement, depending upon the solvent of choice.
- Ariamala, G.,Balasubramanian, K.K.
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p. 3487 - 3488
(2007/10/02)
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