104765-27-7Relevant academic research and scientific papers
Cross-linked polystyrene-TiCl4 complex as a reusable Lewis acid catalyst for solvent-free Knoevenagel condensations of 1,3-dicarbonyl compounds with aldehydes
Rahmatpour, Ali,Goodarzi, Niloofar
, p. 24 - 31 (2019/03/08)
Cross-linked polystyrene copolymer beads with the average particle size in the range of (50–80 mesh size) were prepared by a new method, characterized and functionalized with titanium tetrachloride to afford the corresponding polystyrene?titanium tetrachloride complex in one step reaction and characterized by FT-IR, UV, TGA, DSC, XRD, SEM, BET. This polymer metal complex (PS/TiCl4) was used as a heterogeneous, recoverable, reusable Lewis acid for solvent-free Knoevenagel condensations of 1,3-diketones with aromatic aldehydes under green and mild conditions. The rate of reactions was found to decrease with an increasing percentage of crosslinking and the mesh size of the copolymer beads. This complex showed good stability and catalytic activity in the Knoevenagel reactions.
Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation
Koszelewski, Dominik,Ostaszewski, Ryszard
, p. 10156 - 10164 (2019/07/09)
A new protocol based on lipase-catalyzed tandem reaction toward α,β-enones/enoesters is presented. For the synthesis of the desired products the tandem process based on enzyme-catalyzed hydrolysis and Knoevenagel reaction starting from enol acetates and aldehyde is developed. The relevant impact of the reaction conditions including organic solvent, enzyme type, and temperature on the course of the reaction was revealed. It was shown that controllable release of the active methylene compound from the corresponding enol carboxylate ensured by enzymatic reaction diminishes significantly the formation of the unwanted co-products. Furthermore, this protocol was extended by including a second tandem chemoenzymatic transformation engaging various aldehyde precursors. After a careful optimization of the reaction conditions, the target products were obtained with yields up to 86 % and with excellent E/Z-selectivity.
Design and synthesis of 4-alkyl-2-amino(acetamino)-6-aryl-1,3-thiazine derivatives as influenza neuraminidase inhibitors
Li, Wan,Xia, Lin,Hu, Aixi,Liu, Ailin,Peng, Junmei,Tan, Weiqing
, p. 635 - 644 (2013/09/24)
With a convenient and economical method, two series of 1,3-thiazine derivatives 1 and 2 were synthesized, and their neuraminidase (NA) inhibitory activities were evaluated. The pharmacological results showed that most of the compounds have potent NA inhibitory activity. Especially, 1g exhibited the best activity against influenza virus A (H1N1) NA (IC50 = 29.06 μg/mL), and its crystal structure was determined by single-crystal X-ray diffraction. The preliminary biological assay indicated that 1,3-thiazine could be used as a core structure to design novel influenza NA inhibitors. Two series of novel 1,3-thiazine analogs were synthesized and their neuraminidase (NA) inhibitory activities were evaluated. Most of the compounds have potent NA inhibitory activity. Compound 1g exhibited the best activity against influenza virus A (H1N1) NA with an IC50 of 29.06 μg/mL, and its crystal structure was determined by single-crystal X-ray diffraction.
A facile synthesis of trisubstituted alkenes from β-diketones and aldehydes with AlCl3 as catalyst
Li, Zheng-Nan,Chen, Xiao-Liang,Fu, Yu-Jie,Wang, Wei,Luo, Meng
experimental part, p. 25 - 35 (2012/05/20)
Preparation of trisubstituted alkenes from low-activity β-diketones and aldehydes with aluminum chloride as catalyst has been studied. The frequently used catalyst AlCl3 is used for the first time to promote this condensation. The procedure is a convenient, low toxicity, and highly efficient method for industrial synthesis of trisubstituted alkenes in high yield. Springer Science+Business Media B.V. 2011.
A systematic study on Knoevenagel reaction and Nazarov cyclization of less reactive carbonyl compounds using rare earth triflates and its applications
Ilangovan,Muralidharan,Maruthamuthu
experimental part, p. 1000 - 1006 (2012/02/05)
A systematic study of Knoevenagel reaction and Nazarov cyclization was made on variety of less reactive carbonyl compounds such as β-ketoesters, 1,3-diketones and cyclic active methylene compounds using Yb(OTf)3 as the catalyst. Recycling study confirms reusability of the catalyst without much loss of activity.
Selective reduction of nitroarenes by a Hantzsch 1,4-dihydropyridine: A facile and efficient approach to substituted quinolines
Xing, Rui-Guang,Li, Ya-Nan,Liu, Qiang,Han, Yi-Feng,Wei, Xia,Li, Jing,Zhou, Bo
experimental part, p. 2066 - 2072 (2011/08/05)
An efficient reductive cyclization of o-nitrocinnamoyl compounds was achieved by employing a Hantzsch 1,4-dihydropyridine ester as a biomimetic reducing agent in the presence of catalytic palladium on carbon. This approach was successfully applied to the synthesis of substituted quinolines. Georg Thieme Verlag Stuttgart ? New York.
Studies on cerebral protective agents. I. Novel 4-arylpyrimidine derivatives with anti-anoxic and anti-lipid peroxidation activities
Kuno,Sugiyama,Katsuta,Kamitani,Takasugi
, p. 1452 - 1461 (2007/10/02)
Novel 4-arylpyrimidine derivatives were synthesized by the oxidation of 4-aryl-1,4-dihydropyrimidines, and their effects on anti-anoxic (AA) activity in mice and anti-lipid peroxidation (ALP) activity in rat brain mitochondria were investigated. Among these compounds, ethyl 6-methyl-2-phenyl-4-(4-pyridyl)-5-pyrimidinecarboxylate (4b) has AA activity (10mg/kg, i.p.) and ethyl 6-methyl-4-(3-nitrophenyl)-2-phenyl-5-pyrimidinecarboxylate (4f) has ALP activity (73% inhibition at 10-5 g/ml). The latter compound (100mg/kg, i.p.) was also effective on arachidonate-induced cerebral edema in rats with comparable potency to that of vitamin E.
