27241-29-8Relevant academic research and scientific papers
Fenton-like reactions for pyrazolone ester based heterocyclic dyes with reversible hydrazone-azo tautomerism
Zhao, Xiao-Lei,Wang, Min,Geng, Jiao,Huang, Wei
, (2021)
In this work, two new pyrazolone ester based heterocyclic hydrazone dyes have been prepared and characterized by NMR, FT-IR and MS spectrometry. The acid/base-activated hydrazone-azo tautomerism has been monitored by UV–Vis and 1H NMR spectra.
Three-component reaction for an efficient synthesis of 5-hydroxy-1-phenyl-1H-pyrazoles containing a stable phosphorus ylide moiety
Ghonchepour, Ehsan,Islami, Mohammad Reza,Mostafavi, Hamid,Tikdari, Ahmad Momeni
, p. 459 - 463 (2018)
A concise synthesis of new polysubstituted pyrazoles containing a phosphorane is achieved from readily available organic compounds. This C–H bond functionalization is an efficient means of selectively substituting 4-position of pyrazole to produce a five-membered aromatic ring with a chain containing ylide moiety. This protocol requires no additional catalyst and can be used for other pyrazoles including different substituents.
Method for preparing hydroxyl-substituted pyrazolone dye through Ni(II)/H2O catalytic oxidation
-
Paragraph 0017; 0037-0039, (2020/05/01)
The invention discloses a method for preparing hydroxyl-substituted pyrazolone dye through Ni(II)/H2O2 catalytic oxidation. The in-situ synthesis of the hydroxyl-substituted ester-based pyrazolone dyeis realized through the strong catalytic coordination effect of the metal Ni(II), the strong oxidation capacity of hydrogen peroxide and the demetalization reaction under the acidic condition. UV-Visabsorption spectrum shows that compared with a reaction precursor, the dye with introduced hydroxyl has obvious red shift in absorption wavelength.
Structure-activity relationships in a new class of non-substrate-like covalent inhibitors of the bacterial glycosyltransferase LgtC
Xu, Yong,Cuccui, Jon,Denman, Carmen,Maharjan, Tripty,Wren, Brendan W.,Wagner, Gerd K.
, p. 2973 - 2983 (2018/03/29)
Lipooligosaccharide (LOS) structures in the outer core of Gram-negative mucosal pathogens such as Neisseria meningitidis and Haemophilus influenzae contain characteristic glycoepitopes that contribute significantly to bacterial virulence. An important example is the digalactoside epitope generated by the retaining α-1,4-galactosyltransferase LgtC. These digalactosides camouflage the pathogen from the host immune system and increase its serum resistance. Small molecular inhibitors of LgtC are therefore sought after as chemical tools to study bacterial virulence, and as potential candidates for anti-virulence drug discovery. We have recently discovered a new class of non-substrate-like inhibitors of LgtC. The new inhibitors act via a covalent mode of action, targeting a non-catalytic cysteine residue in the LgtC active site. Here, we describe, for the first time, structure-activity relationships for this new class of glycosyltransferase inhibitors. We have carried out a detailed analysis of the inhibition kinetics to establish the relative contribution of the non-covalent binding and the covalent inactivation steps for overall inhibitory activity. Selected inhibitors were also evaluated against a serum-resistant strain of Haemophilus influenzae, but did not enhance the killing effect of human serum.
Viable and straightforward approach to the preparation of water soluble pyrazol-5-one derivatives through glycoconjugation
Bianchini, Roberto,Bonanni, Marco,Corsi, Massimo,Infantino, Angela Simona
, p. 8636 - 8644 (2012/10/29)
The synthesis of water soluble pyrazol-5-one azo-dyes has been achieved. 6′-Aminolactosetriacetonide 9 was selected as the key building block to glyconjugate the pyrazole ring at its 3 position via a carboxamide or via a benzeneamide moiety in position 1 of the heterocycle. Diethyl-3-oxopentandionate 2 led eventually to a bicyclic compound, hampering the glyconjugation coupling process. The values of the molar extinction coefficients (ε) confirmed the tendency of pyrazolone azo dyes to exist in their tautomeric hydrazo form (especially in polar solvents); whereas the presence of substituents on the phenylazo group influenced the visible absorption maxima negligibly.
1,1,1-Trichloro-4,4-diethoxy-3-buten-2-one and its Trichloroacetylacetate Derivatives: Synthesis and Applications in Regiospecific Preparation of Azoles
Martins, Marcos A. P.,Pereira, Claudio M. P.,Zimmermann, Nilo E. K.,Moura, Sidnei,Sinhorin, Adilson P.,Cunico, Wilson,Zanatta, Nilo,Bonacorso, Helio G.,Flores, Alex C. F.
, p. 2353 - 2357 (2007/10/03)
The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The t
