- 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 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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- Anthracene derivatives compounds and organic electroluminescent devices comprising the same
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The present invention relates to a novel organic electroluminescent compound which is represented by the following [chemical formula 1] or [chemical formula 2]. The electroluminescent compound according to the present invention has high glass transition temperature, thereby having enhanced thermal stability; and can form an organic electroluminescent device having low driving voltage, high luminance, high color purity, and long-life when applying the same to the electroluminescent device.
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Paragraph 0284; 0288; 0391; 0397-0401
(2020/07/28)
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- A new method for the synthesis of six bromine four hydrogen colors chromone (by machine translation)
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The invention discloses a method for synthesizing six bromine four hydrogen colors recombination, is in the reaction solvent, to phenol and acrylonitrile reaction raw material, under the action of the organic drugs, six bromine four hydrogen colors recombination reaction. The invention mild reaction conditions, cheap raw material, the value of the product is very high. This invention synthetic six bromine four hydrogen colors recombination has very high medicinal value, conducive to diabetes, obesity, disorders of the nervous system in the fields of research and development of new drugs, has extensive use and application market. (by machine translation)
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Paragraph 0022; 0035
(2017/07/13)
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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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- A facile solvent free synthesis of 3-arylidenechroman-4-ones using grinding technique
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An efficient method for the synthesis of 3-arylidenechroman-4-ones has been developed under solvent free conditions using grinding technique. Grinding of variously substituted chroman-4-ones with aromatic aldehydes in presence of anhydrous barium hydroxide at room temperature give 3-arylidenechroman-4-ones in high yield (75-92%). Products are obtained by just acidification of the reaction mixture in ice cold water. Reaction in solid state, with enhanced rate, high selectivity and manipulative simplicity are the attractive features of this environmentally benign protocol. The chroman-4-one derivatives required for the reaction have been obtained by polyphosphoric acid (PPA) catalysed cyclisation of phenoxypropanoic acids under microwave irradiations.
- Kumar, Suresh,Makrandi, Jagdish K.
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experimental part
p. 1251 - 1256
(2012/05/20)
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- An efficient synthesis of 4-chromanones
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A two step efficient and practical synthesis of a variety of 4-chromanones is described. Phenols undergo a Michael addition to acrylonitriles in the presence of catalytic amounts of potassium carbonate and tert-butanol to generate the corresponding 3-aryloxypropanenitriles in 50-93% yields. Treatment of the resulting aryloxypropionitriles with 1.5 equiv of TfOH and 5 equiv of TFA, followed by an aqueous work up afforded 4-chromanones in moderate to excellent yields.
- Zhong, Yong-Li,Boruta, David T.,Gauthier Jr., Donald R.,Askin, David
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supporting information; experimental part
p. 4824 - 4826
(2011/10/04)
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- Efficient synthesis of chromones with alkenyl functionalities by the heck reaction
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The usefulness of the Heck reaction in the field of chromones has been demonstrated. Bromochromones with the halogen atom in their rings A and B were reacted with various terminal alkenes to give hitherto unknown alkenyl-substituted chromones. Reactivity of the substrates was found to markedly depend on the position of the bromine atom. Under phosphine-free conditions using a phase-transfer catalyst additive (tetrabutylammonium bromide), shorter reaction periods and usually higher yields were obtained.
- Patonay, Tams,Vasas, Attila,Kiss-Szikszai, Attila,Silva, Artur M. S.,Cavaleiro, Jos A. S.
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experimental part
p. 1582 - 1593
(2011/08/04)
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- Design, synthesis, and biochemical evaluation of novel cruzain inhibitors with potential application in the treatment of Chagas' disease
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A series of compounds bearing tetrahydronaphthalene, benzophenone, propiophenone, and related rigid molecular skeletons functionalized with thiosemicarbazone or unsaturated carbonyl moieties were prepared by chemical synthesis and evaluated for their ability to inhibit the enzyme cruzain. As potential treatment agents for Chagas' disease, three compounds from the group demonstrate potent inhibition of cruzain with IC50 values of 17, 24, and 80 nM, respectively.
- Siles, Rogelio,Chen, Shen-En,Zhou, Ming,Pinney, Kevin G.,Trawick, Mary Lynn
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p. 4405 - 4409
(2007/10/03)
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- N-heterocyclic carbene catalyzed nucleophilic substitution reaction for construction of benzopyrones and benzofuranones
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N-Heterocyclic carbene as an efficient organic catalyst was employed to catalyze an intramolecular nucleophilic substitution reaction. When R 2 was a phenyl group, the cyclization process underwent isomerization, leading to generation of benzofuranone.
- He, Jinmei,Zheng, Jiyue,Liu, Jian,She, Xuegong,Pan, Xinfu
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p. 4637 - 4640
(2007/10/03)
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- OXAZOLIDINONE DERIVATIVES N-SUBSTITUTED BY A BICYCLIC RING, FOR USE AS ANTIBACTERIAL AGENTS
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Compounds of formula (I) and methods for their preparation are disclosed. Further disclosed are methods of making biologically active compounds of formula (I) as well as pharmaceutically acceptable compositions comprising compounds of formula (I). Compoun
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Page/Page column 98
(2010/02/08)
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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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- Anti-inflammatory and analgesic benzothiophene and benzafuran derivatives, compositions, and method of use therefor
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Compounds of formula (I): STR1 wherein: Ar is phenyl optionally substituted in the o-, m- or p-position by C1-4 alkyl, C1-4 alkoxy, trifluoromethyl, bromo, chloro or fluoro, pyrryl optionally N-substituted by C1-4 alkyl, 2-furyl or 2-thienyl either optionally substituted in the 3-, 4- or 5-position by methyl, chloro or bromo, or 3-furyl or 3-thienyl; X is oxygen, sulphur, sulphoxide or sulphone, Y is methylene, R1 and R3 are hydrogen or C1-4 alkyl, and R2 is hydrogen, C1-4 alkyl, fluoro, chloro or bromo, or X is methylene, Y is oxygen, R1 and R3 are both hydrogen, and R2 is hydrogen, fluoro, chloro or bromo; and R4 is hydrogen or C1-4 alkyl, or a salt thereof, have analgesic and/or anti-inflammatory activity.
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