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21.
The use of dimedone in green chemistry has been described for the synthesis of selective heterocyclic motifs which are both pharmacologically and industrially important. The objective of this review is to summarize some of the selected recent advances of dimedone in the synthesis of organic compounds utilizing green chemistry procedures. 相似文献
22.
Lal Sohan Arora Sanjiv Kumar Vinod Rani Shikha Sharma Chetan Kumar Parvin 《Journal of Thermal Analysis and Calorimetry》2018,132(3):1707-1716
Journal of Thermal Analysis and Calorimetry - The synthesis of Schiff bases of chitosan is performed by the reaction of chitosan with different heteroaryl aldehydes, i.e., furfuraldehyde,... 相似文献
23.
Yedukondalu Nalli Palak Arora Syed Riyaz-Ul-Hassan Asif Ali 《Tetrahedron letters》2018,59(25):2470-2472
The discovery of a new spiran based natural product, prenylspirodinone (1), together with six known cannabinoids (2–7) from the leaves of Cannabis sativa (Marijuana) is reported. All compounds were screened for antifungal and antibacterial activity against a panel of microbial pathogens and exhibited antimicrobial activities with IC50 values ranging from 2.6 to 49.6?µM. Compound 2, a propyl substituted cannabidiol, was determined to be a specific inhibitor against C. albicans (IC50 11.9?µM) and can be considered as a new lead against Candidiasis. 相似文献
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25.
Synthesis of a novel class of multinucleate pyrimidine chalcogen (S/Se/Te) derivatives has been successfully attempted for the first time by the selective substitution of chlorine at the C-2 position of 2,4-dichloropyrimidine with nucleophilic dichalcogenide anion E22− (E = S, Se, Te) to afford bis[4-chloro-2-pyrimidyl] dichalcogenide. The highly electrophilic nature of 2,4-dichloropyrimidine compared to aryl chlorides has been further exploited to prepare a variety of 4-chloro-2-(arylchalcogenyl) pyrimidine compounds by substituting the chlorine exclusively at the C-2 position of 2,4-dichloropyrimidine with a variety of chalcogen bearing aryl anions ArE− (Ar = phenyl, 1-naphthyl, p-tolyl, 4,6-dimethyl-2-pyrimidyl, 2-pyridyl, 4-methyl-2-pyridyl). All the newly prepared symmetrical and unsymmetrical pyrimidyl chalcogen compounds have been thoroughly characterized with the help of various spectroscopic techniques viz., NMR (1H, 13C, 77Se), FT-IR and mass spectrometry (in representative cases). The crystal structures of 4-chloro-2-(phenylselanyl) pyrimidine and 2-(p-tolylselanyl)-4-chloropyrimidine have been determined by X-ray crystallography. 相似文献
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27.
Ramesh C. Kamboj Dinesh Kumar Rita Arora Surinder Berar Geeta Sharma 《Journal of heterocyclic chemistry》2013,50(Z1):E200-E203
The photo‐irradiation of thienylchromenone resulted in the regioselective cyclization which is exclusively controlled by the nature of solvent used as reaction medium. Compared to nonpolar medium, polar solvent furnished a diverse array of novel angular tetracyclic photoproducts with gem‐dihydro functionality and exocyclic double bonds on the fused pyran ring, which is unprecedented to best of our knowledge. 相似文献
28.
High pressure behavior of alpha-hydroquinone (1,4-dihydroxybenzene) has been studied using Raman spectroscopy up to pressures of 19 GPa. Evolution of Raman spectra suggests two transitions around 3.3 and 12.0 GPa. The first transition appears to be associated with the lowering of crystal symmetry. Above 12.0 GPa, Raman bands in the internal modes region exhibit continuous broadening suggesting that the system is progressively evolving into a disordered state. This disorder is understood as arising due to distortion of the hydrogen-bonded cage across the second transition around 12 GPa. 相似文献
29.
Herein we describe a strategy for the preparation of artificial alpha-helices involving replacement of one of the main-chain hydrogen bonds with a covalent linkage. To mimic the C=O...H-N hydrogen bond as closely as possible, we envisioned a covalent bond of the type C=X-Y-N, where X and Y are two carbon atoms connected through an olefin metathesis reaction. Our results demonstrate that the replacement of a hydrogen bond between the i and i + 4 residues at the N-terminus of a short peptide with a carbon-carbon bond results in a highly stable constrained alpha-helix at physiological conditions as indicated by CD and NMR spectroscopies. The advantage of this strategy is that it allows access to short alpha-helices with strict preservation of molecular recognition surfaces required for biomolecular interactions. 相似文献
30.
Multifunctionalized tetrahydropyrimidines derivatives have been synthesized from Biginelli 3,4-dihydropyrimidin-2-(1H)-thiones (DHPMs) efficiently. The transformation includes desulfurization of DHPMs with Raney-Ni and subsequent regioselective C-2 functionalization using a variety of C-nucleophiles with simultaneous activation with ethyl chloroformate. Functionalized pyrimidine derivatives containing bulky substituents at C-2 of the pyrimidine ring are cytostatic. 相似文献