27406-31-1Relevant articles and documents
Assessing the potential of para-donor and para-acceptor substituted 5-benzylidenebarbituric acid derivatives as push–pull electronic systems: Experimental and quantum chemical study
Stojiljkovi?, Ivana N.,Ran?i?, Milica P.,Marinkovi?, Aleksandar D.,Cvijeti?, Ilija N.,Mil?i?, Milo? K.
supporting information, (2021/02/26)
Electronic interactions in donor-π-linker-acceptor systems with barbituric acid as an electron acceptor and possible electron donor were investigated to screen promising candidates with a push–pull character based on experimental and quantum chemical studies. The tautomeric properties of 5-benzylidenebarbituric acid derivatives were studied with NMR spectra, spectrophotometric determination of the pKa values, and quantum chemical calculations. Linear solvation energy relationships (LSER) and linear free energy relationships (LFER) were applied to the spectral data - UV frequencies and 13C NMR chemical shifts. The experimental studies of the nature of the ground and excited state of investigated compounds were successfully interpreted using a computational chemistry approach including ab initio MP2 geometry optimization and time-dependent DFT calculations of excited states. Quantification of the push–pull character of barbituric acid derivatives was performed by the 13CNMR chemical shift differences, Mayer π bond order analysis, hole-electron distribution analysis, and calculations of intramolecular charge transfer (ICT) indices. The results obtained show, that when coupled with a strong electron-donor, barbituric acid can act as the electron-acceptor in push–pull systems, and when coupled with a strong electron-acceptor, barbituric acid can act as the weak electron-donor.
Microwave-associate synthesis of Co3O4 nanoparticles as an effcient nanocatalyst for the synthesis of arylidene barbituric and Meldrum's acid derivatives in green media
Yahyazadehfar, Mahdieh,Sheikhhosseini, Enayatollah,Ahmadi, Sayed Ali,Ghazanfari, Dadkhoda
, (2019/08/02)
In this study, Co3O4 nanocatalysts were constructed in environmentally appropriate conditions using controlled, effective, and facile microwave method. The final nanostructures were characterized by SEM, XRD, and TEM analyses. The products had a small size distribution, homogeneous morphology, and crystallographic structures associated with the formation of Co3O4 nanostructures. Moreover, EDS mapping analysis confirmed the existence of Co and O elements in the final structure, and the magnetic properties of the samples were investigated by VSM. The application of this nanostructure in a catalytic process was further examined, and the results suggested that it could be used as a novel candidate for the synthesis of arylidene barbituric and Meldrum,s acid through Knoevenagel condensation of aldehydes by barbituric and Meldrum,s acid in aqueous media. The high yield of these nanocatalysts would be justified by the nature of the nanostructure as well as the experimental procedure developed in this study, which affected the physicochemical features of the products.
Verjuice as a green and bio-degradable solvent/catalyst for facile and eco-friendly synthesis of 5-arylmethylenepyrimidine-2,4,6-trione, pyrano[2,3-d]pyrimidinone and pyrimido[4,5-d]pyrimidinone derivatives
Safari, Niloufar,Shirini, Farhad,Tajik, Hassan
, p. 887 - 897 (2019/03/27)
Verjuice (unripe grape juice), a natural mixture of organic acids, which is identified by pH-metric and TGA analysis, is efficiently used for the promotion of the synthesis of 5-arylmethylenepyrimidine-2,4,6-triones, via Knovenagel condensation reaction between barbituric or thiobarbituric acid and aldehydes. Verjuice is also employed for the effective synthesis of pyrano[2,3-d]pyrimidinone derivatives via a three-component reaction of barbituric acid or its thio analogue, aldehydes and malononitrile. In the same way, pyrimido[4,5-d]pyrimidinone derivatives are simply produced via the reaction of barbituric acid, aldehydes and urea or thiourea in the presence of verjuice. This green methodology rewards notable advantages including simple procedures, acceptable reaction times, easy work-up, high yields, circumventing the use of any expensive starting materials, volatile and hazardous organic solvents during the reaction and work-up process, and use of a natural, low-cost, reusable, and bio-degradable catalyst.