Study of the Fischer cyclization of diarylhydrazones and related secondary hydrazones I. Relative orienting capacity of the p-methyl and p-methoxy groups of diarylhydrazines

1975 ◽  
Vol 11 (10) ◽  
pp. 1156-1161
Author(s):  
V. A. Zagorevskii ◽  
N. F. Kucherova ◽  
N. M. Sharkova ◽  
T. I. Ivanova ◽  
S. M. Klyuev
Keyword(s):  
Fischer Cyclization ◽  
Methoxy Groups

Proximity and conformation effects in 29Si and 13C NMR spectra of di-ortho substituted trimethylsiloxybenzenes

1990 ◽  
Vol 55 (8) ◽  
pp. 2027-2032 ◽  
Author(s):  
Jan Schraml ◽  
Robert Brežný ◽  
Jan Čermák
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Proximity Effect ◽  
Nmr Spectra ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Proximity Effects ◽  
13C Nmr Spectra ◽  
Methoxy Groups ◽  
C Nmr

29Si and 13C NMR spectra of five 4-substituted 2,6-dimethoxytrimethylsiloxybenzenes were studied with the aim to elucidate the nature of the deshielding proximity effects observed in the spectra of ortho substituted trimethylsiloxybenzenes. The sensitivity of 29Si chemical shifts to para substitution is in the studied compounds essentially the same as in mono ortho methoxytrimethylsiloxybenzenes. The deshielding proximity effect of the ìsecondî methoxy group is somewhat smaller than that of the ìfirstî group. The present results indicate that the two methoxy groups assume coplanar conformations with the benzene ring and are turned away from the trimethylsiloxy group which is not in the benzene plane. It is argued that in mono ortho methoxytrimethylsiloxybenzenes the two substituent groups adopt the same conformations as in the compounds studied here.

Reaction pathways for the HDO of guaiacol over supported Pd catalysts: Effect of support type in the deoxygenation of hydroxyl and methoxy groups

2021 ◽  
pp. 111491
Author(s):  
Camila A. Teles ◽  
Priscilla M. de Souza ◽  
Raimundo C. Rabelo-Neto ◽  
Alejandra Teran ◽  
Gary Jacobs ◽  
...  
Keyword(s):  
Reaction Pathways ◽  
Pd Catalysts ◽  
Supported Pd Catalysts ◽  
Methoxy Groups ◽  
Effect Of Support ◽  
Supported Pd

Methoxy groups increase water and decrease salt permeability properties of sulfonated polysulfone desalination membranes

2021 ◽  
Vol 630 ◽  
pp. 119298
Author(s):  
Kevin Chang ◽  
Hongxi Luo ◽  
Sean M. Bannon ◽  
Sin Yan Lin ◽  
Wendy-Angela Saringi Agata ◽  
...  
Keyword(s):  
Sulfonated Polysulfone ◽  
Methoxy Groups

scholarly journals Fluorine substituted methoxyphenylalkyl amides as potent melatonin receptor agonists

MedChemComm ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 460-464 ◽  
Author(s):  
Andrew Tsotinis ◽  
Rodanthi Kompogennitaki ◽  
Ioannis Papanastasiou ◽  
Peter J. Garratt ◽  
Alina Bocianowska ◽  
...  
Keyword(s):  
Side Chain ◽  
Melatonin Receptor ◽  
Receptor Agonists ◽  
Methoxy Groups ◽  
Melatonin Receptor Agonists

A series of fluorine substituted methoxyphenylalkyl amides were prepared with different orientations of the fluorine and methoxy groups with respect to the alkylamide side chain and with alkyl sides of differing lengths (n= 1–3).

Synthesis, photophysical and photochemical properties of highly soluble phthalocyanines substituted with four 3,5-dimethylpyrazole-1-methoxy groups

2011 ◽  
Vol 696 (23) ◽  
pp. 3807-3815 ◽  
Author(s):  
Rıza Bayrak ◽  
Hakkı Türker Akçay ◽  
Mahmut Durmuş ◽  
İsmail Değirmencioğlu
Keyword(s):  
Methoxy Groups ◽  
Photochemical Properties

scholarly journals Mechanism of tubulin–colchicine recognition: a kinetic study of the binding of the colchicine analogues colchicide and isocolchicine

1997 ◽  
Vol 327 (3) ◽  
pp. 685-688 ◽  
Author(s):  
Chantal DUMORTIER ◽  
Qunying YAN ◽  
Susan BANE ◽  
Yves ENGELBORGHS
Keyword(s):  
Rate Constant ◽  
Total Concentration ◽  
Carbonyl Oxygen ◽  
Protein Fluorescence ◽  
Kinetic And Thermodynamic Parameters ◽  
Methoxy Groups ◽  
Displacement Experiments ◽  
Absorbance Changes ◽  
Initial Binding

Colchicide (IDE) is a colchicine (COL) analogue in which the C-10 methoxy group is replaced by a hydrogen atom. Its binding to tubulin is accompanied by a quenching of the protein fluorescence. The fluorescence decrease shows a monoexponential time dependence. The observed rate constant increases in a non-linear way with the total concentration of IDE, allowing the determination of a binding constant for an initial binding site (K1 = 5300±300 M-1) and the rate constant for the subsequent isomerization (k2 = 0.071±0.002 s-1) at 25 °C. The rate constant, k-2, for the reversed isomerization can be determined by displacement experiments. Despite the minor alteration of the C-ring substituent, the kinetic and thermodynamic parameters of binding are substantially different from those of COL itself, for both steps. In isocolchicine (ISO) the carbonyl oxygen atom and the methoxy groups of the C-ring have been interchanged. Its binding to tubulin only results in small fluorescence and absorbance changes. Therefore competition experiments with MTC [2-methoxy-5-(2ʹ,3ʹ,4ʹ-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-one] were performed. ISO competes rapidly and with low affinity with MTC. Fluorimetric titrations of tubulin with MDL (MDL 27048 or trans-1-(2,5 dimethoxyphenyl)-3-[4-(dimethylamino)phenyl]-2-methyl-2-propen-1-one) in the presence and absence of ISO give evidence for the existence of a second, slow-reacting low-affinity site for ISO that is not accessible to MTC or MDL. The relevance of these results for the recognition of COL is analysed.

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