Display omitted
Nanoporous silicate materials, made by an operationally simple evaporation-induced self-assembly (EISA) approach, efficiently catalyze the formation of 2-substituted ...2,3-dihydroquinazolin-4(1H)-ones from aldehydes and dimethyl acetals. This methodology can be extended to encompass the reaction of ketones and ketals to provide facile access to 2,2-disubstituted and spiro dihydroquinazolin-4(1H)-ones in high yields and short reaction times.
In(OTf)3 (4c)-mediated one-pot (4+2) cyclocondensation of γ-alkynones 3 with N2H4(aq) in dioxane affords substituted pyridazines 5 in good yields via a sequential desulfonative or dehydrogenative ...aromatization. The facile transformation proceeds by a facile synthetic sequence starting with an α-propargylation of β-ketosulfones 1 and a cyclocondensation of γ-alkynones 3 with N2H4(aq). The method provides a mild and efficient condition. Moreover, this route can be enlarged to multigram scale.
Display omitted
The regioselectivity of the 3+2 cyclocondensation of trifluoromethyl‐α,β‐ynones with hydrazines can be readily tuned to preferentially afford either 3‐ or 5‐trifluoromethylpyrazoles through variation ...of the reaction conditions. Under catalysis with copper(II) acetate (2.0 mol%), cyclocondensation proceeded smoothly to yield 3‐trifluoromethylpyrazoles with high regioselectivity. In contrast, when the reaction was conducted in dimethyl sulfoxide under catalyst‐free conditions, the formation of 5‐trifluoromethylpyrazoles was predominantly observed.
Quinoxaline derivatives have been synthesized in good to excellent yields by the cyclocondensation reaction of o-pheneylenediamine with substituted phenacyl bromides/benzil in the presence of SO
4
2−
.../ZrO
2
-TiO
2
as an efficient and heterogeneous catalyst. The catalyst can be recovered up to five catalytic cycles without significant loss in catalytic activity. The reported SO
4
2−
/ZrO
2
-TiO
2
catalyst has been thoroughly characterized by using infrared spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD). Here, we have used ethanol as a green solvent in this cyclocondensation. This new method has several advantages, such as excellent yields, short reaction time, nontoxic, and easily recoverable catalyst.
•A reusable anionic resin as catalyst for the synthesis of benzimidazole and benzothiazole compounds.•Two compounds were optimized using DFT method, B3LYP/6-311G(d,p)basis set.•HOMO - LUMO and (MEP) ...of the compounds were studied.•NLO properties of selected two compounds were performed.•Molecular Docking was performed to establish the biological significance.
A series of pharmaceutically valuable, functionalized fused heteroaromatic compounds such as benzimidazoles, and benzothiazoles have been synthesized via catalytic cyclocondensation between o-phenylenediamine, or o-aminothiophenol, and aryl aldehydes at ambient conditions. The Amberlite IRA400-Cl anionic resin has proved to be an efficient green catalyst in this protocol. The salient features of this method are the mild condition, easy work-up, an excellent yield of product, green catalyst, and reusability of the catalyst. Theoretical studies on selected compounds have been carried out using Density Functional Theory (DFT) method and Gaussian 09 package, B3LYP 6-311G(d,p) basis set. Molecular docking studies were also performed on selected compounds to determine their pharmaceutical activities.
Display omitted
Display omitted
The synthesis of 3-arylquinolines through a cyclocondensation of 2-aminoarylmethanols and benzaldehydes in DMSO promoted by KOtBu has been developed. In this procedure, DMSO is used ...not only as a solvent, but also a C1 source incorporated into the 2-position of quinoline ring.
An environmental friendly, NIS mediated oxidative cyclocondensation of 2-aminopyridine and aryl methyl ketone/cinnamaldehydes has been realized for the synthesis of 2-arylimidazo 1,2-apyridines and ...their 3-formylated products respectively. This one pot protocol involves simple reaction conditions, tolerates wide range of substrates and the products were formed in good to excellent yields.
Display omitted
•A new pyrazole derivative was synthesized, characterized spectroscopically and its 3D structure was determined using X-ray diffraction.•The crystal structure is stabilized by intermolecular C-H•••O ...and π•••π interactions.•NMR, IR, TD-SCF, HOMO/LUMO, MEP, Mullikan charges and HSA were theoretically computed•DPPH and Hydroxyl radical scavenging activity screening shows that it could be a potent antioxidant.
An effective route for the direct synthesis of substituted pyrazole through 3+2 annulation method was described. (E)-ethyl 2-benzylidene-3-oxobutanoate was prepared from ethyl acetoacetate and benzaldehyde via Knoevenagel approach. The cyclocondensation reaction of (E)-ethyl 2-benzylidene-3-oxobutanoate with phenylhydrazine hydrochloride in acetic acid (30%) medium under reflux conditions produced directly ethyl 1-(2,4-dimethylphenyl)-3-methyl-5-phenyl-1H-pyrazole-4-carboxylate and was characterized using spectroscopic methods viz NMR, mass, UV-Vis, and CHN analysis. The compound obtained was crystallized using methyl alcohol solvent by slow evaporation method and the 3D molecular structure was confirmed using single crystal X-ray diffraction studies. The crystal structure is stabilized by intermolecular hydrogen bond of the type C-H•••O and π•••π stacking interactions. Further, the calculated 1H-NMR, TD-SCF, HOMO/LUMO, MEP, Hirshfeld surface and Mulliken population analysis were compared with the experimentally analyzed data. The optimized theoretical structure parameters are in good agreement with the experimental X-ray structures. The compound was evaluated in vitro for its antioxidant susceptibilities through DPPH and hydroxyl radical scavenging methods.
Display omitted
