نتایج جستجو برای: chromene
تعداد نتایج: 842 فیلتر نتایج به سال:
Chromene is considered a fused pyran ring with benzene ring, which found in many plants and part of important compounds such as anthocyanidins, anthocyanins, catechins, flavanones. These are included under the headings "flavonoids" "iso-flavonoids." well known bioactive molecules wide medicinal uses. According to these pharmacokinetic characteristics, researchers giving more attention this type...
The reaction of a chromene with BH(3) followed by treatment with benzoquinone and air is the key step in a direct entry to O-methyl claussequinone.
A new red fluorescent sensor DCCP-Cu2+ based on dicyanomethylene-4H-chromene shows turn-on fluorescence with high selectivity for pyrophosphate over other anions.
Two possible isomers of some 1,3-diaryl-H-benzo[f]chromene have been studied using density functional theory. Structures of E1 and E2 isomers were optimized at the B3LYP and MP2 levels with different basis sets. The total electronic energies show that E2 isomer is about 3-5 kcal/mol more stable than E1 isomer and this energy difference is attributed to the planarity of heterocyclic ring and mor...
To discover new bioactive lead compounds for medicinal purposes, 2-cyano-3-(4-substituted)-N-(quinolin-3-yl) acrylamide derivatives 2-24, chromenes 25, 26 and benzochromenes 27, 28 were synthesized. The structures of the newly synthesized compounds were confirmed by elemental analyses, IR, 1H NMR and 13C NMR spectroscopies. In addition, the structure of compound 1 was confirmed through X-ray cr...
BACKGROUND AND AIMS In the context of the increasing phenomenon of microbial resistance to usual drugs, the development of new treatment strategies and new therapeutic protocols is a constant need. Thiazolidinedione and chromone represent two important scaffolds in medicinal chemistry due to their large pharmacological applicability. METHODS We synthesized a new 5-(chromene-3-yl)methylene-2,4...
Demethylisoencecalin (1) and caleins A (4) and C (5) (3.16-31.6 mg/kg, p.o.), the major components from an infusion of Calea ternifolia controlled postprandial glucose levels during an oral sucrose tolerance test (OSTT, 3 g/kg) in normal and nicotinamide/streptozotocin (NA/STZ, 40/100 mg/kg) hyperglicemic mice. The effects were comparable to those of acarbose (5 mg/kg). During the isolation of ...
the ionic liquid li(ohch2ch2nh2)(cf3oac) was found to efficiently catalyze the three-component reaction between different enols, aldehydes, and malononitrile , leading to rapid synthesis of 2-amino-4h-chromene derivatives in fairly high yields. the catalyst is easily prepared, highly stable, simple to handle and recycled for several times without significant loss of activity. the method is simp...
The cesium carbonate-mediated reaction of 2-bromoallyl sulfones and ortho-hydroxychalcones furnished 3-arylsulfonyl-4H-chromene derivatives in 58-67% yield (18 examples). 2-Bromoallyl sulfones functioned as synthetic surrogates for allenyl sulfones in the reaction.
sucrose is applied as an efficient catalyst for the three-component reaction consisting of aromatic aldehydes, malononitrile and resorcinol in a mixture of water and ethanol media as green solvents. the advantages of this method are excellent yeild, inexpensive catalyst and more environmentally friendly. mechanistic insight into the synthesis of 2-amino-4h-chromene included spectral kinetics ap...
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