The synthesis of 3-(4-alkyl-4,5-dihydropyrrolo[1,2-a]quinoxalin-4-yl)-2H-chromen-2-one derivatives by a three-component reaction of salicylaldehyde, β-keto esters, and 1-(2-aminophenyl)pyrrole using piperidine–iodine as a dual system catalyst is reported. Good yields, mild reaction conditions, and ease of handling are the main aspects of the method. The structural assignments are supported by 1H NMR, 13C NMR, and X-ray crystallography data. 相似文献
Nickel(II) and copper(II) complexes of two unsymmetrical tetradentate Schiff base ligands [Ni(Me-salabza)] (1), [Cu(Me-salabza)] (2) and [Ni(salabza)] (3), {H2salabza = N,N′-bis[(salicylidene)-2-aminobenzylamine] and H2Me-salabza = N,N′-bis[(methylsalicylidene)-2-aminobenzylamine]}, have been synthesized and characterized by elemental analysis and spectroscopic methods. The crystal structures of 2 and 3 complexes have been determined by single crystal X-ray diffraction. Both copper(II) and nickel(II) ions adopt a distorted square planar geometry in [Cu(Me-salabza)] and [Ni(salabza)] complexes. The cyclic voltammetric studies of these complexes in dichloromethane indicate the electronic effects of the methyl groups on redox potential. 相似文献
Journal of Solid State Electrochemistry - A facile and sensitive approach is introduced to precisely determine trace amounts of prostate specific antigen (PSA) by gold nanostructures deposited on... 相似文献
Summary The reaction between alkyl isocyanides and isopropylidene Meldrum’s acid in the presence of 1,2-ethanediol leads to N1-(alkyl)-2-(5,7-dioxo-1,4-dioxepane-6-yl)-2-methylpropanamides. 1,3-Propanediol or 1,4-butanediol produce hydroxyalkyl 1-(tert-butyl)-4,4-dimethyl-2,5-dioxo-3-pyrrolidinecarboxylates. When the reaction was performed in the presence of catechol, bis(2-hydroxyphenyl)
2-[2-(tert-butylamino)-1,1-dimethyl-2-oxoethyl]malonate was obtained. 2-Aminophenols react with alkyl isocyanides in the presence of
isopropylidene Meldrum’s acid to produce 1-alkyl-N3-(2-hydroxyaryl)-4,4-dimethyl-2,5-dioxo-3-pyrrolidinecarboxamides in good yields. 相似文献
Multiwalled carbon nanotubes were exposed to hydrothermal treatment for obtaining graphene oxide nanoribbons (GONRs). The fabricated graphene oxide nanoribbons have been morphologically and compositionally characterized via FE-SEM, XRD, and FT-IR techniques. The as-synthesized GONRs have been used as sorbent phase for headspace solid-phase microextraction of phthalate esters (PEs) from aqueous solutions. In this regard, the GC–FID analysis route has been used for quantification of PEs. The new SPME fiber shows remarkable analytical figures of merit including broad dynamic linear ranges, low limits of detection, as well as good stability and reasonable relative standard deviations for evaluation of PEs. The linearity of the method for analysis of PEs including DnBP, DnPP, DEHP, DEHA, BBP, and DMP was between the range of 0.05–100, 0.05–100, 0.1–100, 0.1–100, 0.2–100, and 0.5–100 μg L?1, respectively. The limits of detection (based on S/N?=?3) and correlation coefficients were found to be in the range of 0.02–0.2 μg L?1 and 0.9907–0.9952, correspondingly. The prepared GONR-coated SPME fiber shows larger extraction yield in comparison to pristine MWNTs and commercial PDMS SPME fibers. Furthermore, real sample analysis showed that there is no significant matrix effect for evaluation of PEs from environmental water samples and proposed method could be used for evaluation and determination of PEs from aqueous samples in a precise and accurate manner. The existence of functional groups, π–π interactions, as well as hydrogen bonding between adsorbent phase and PE analytes could be the reason for observing such a high extraction yield.
Research on Chemical Intermediates - The aim of present investigation is the synthesis of mesoporous catalyst based on hexagonal mesoporous silica. HMS support has exceptional properties such as... 相似文献
A structural study of a hierarchical zeolite X, which is similar to the one first synthesized by Inayat et al., 12 was performed using transmission electron microscopy imaging and diffraction. Evidence is provided, by comparison to simulations, that this material is an intergrowth of FAU and EMT and a conceptual model is presented for the growth of the FAU material with a small fraction of EMT in an atypical morphology of assembled sheets with well‐defined intersection angles. 相似文献
An efficient synthesis of Biginelli-type compounds using potassium phthalimide as a green, mild, and commercially available organocatalyst in a one-pot, multi-component cyclocondensation reaction of cyclopentanone, aldehydes, and urea/thiourea is reported. The present methodology is a green approach to access 4-aryl-7-(aryImethylene)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-ones/thiones. It offers several merits such as simple operational procedures, no use of hazardous organic solvents, and cheap and environmentally friendly solid basic catalyst. 相似文献
Type 2 diabetes mellitus is the result of resistance to insulin function along with inadequate insulin secretion, leading to a number of dysfunctions characterized by hyperglycemia, and it is associated with microvascular, macrovascular, and neuropathic complications. There is compelling evidence that the decline in both insulin sensitivity and insulin secretion has a genetic component. In addition, increasing evidence suggests that microRNAs (miRNAs) as key regulators of gene expression play significant roles in insulin production, secretion, and function that regulate the function of insulin-target tissues. The current review demonstrates the candidate genes and the related miRNAs involved in molecular pathogenesis of insulin resistance in type 2 diabetes mellitus. In doing so, it provides an opportunity for more focused investigations that may identify the genes and miRNAs with a role in the pathogenesis of type 2 diabetes mellitus and its treatment. 相似文献