Utilization of a Methoxy Group in Lignin to Prepare Amides by the Carbonylation of Amines

2021 ◽  
Author(s):  
Dejin Zhang ◽  
Guoqiang Yang ◽  
Xingbang Hu ◽  
Zhibing Zhang
Keyword(s):  
Methoxy Group

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.

Design of a13C Magnetic Resonance Probe Using a Deuterated Methoxy Group as a Long-Lived Hyperpolarization Unit

2012 ◽  
Vol 51 (40) ◽  
pp. 10114-10117 ◽  
Author(s):  
Tomohiro Doura ◽  
Ryunosuke Hata ◽  
Hiroshi Nonaka ◽  
Kazuhiro Ichikawa ◽  
Shinsuke Sando
Keyword(s):  
Magnetic Resonance ◽  
Methoxy Group

Preparation of Some 2-(Methoxyphenyl)-2H-benzotriazoles and the Corresponding Hydroxyphenyl Compounds

1987 ◽  
Vol 40 (10) ◽  
pp. 1663 ◽  
Author(s):  
J Rosevear ◽  
JFK Wilshire
Keyword(s):  
Acetic Acid ◽  
Good Yield ◽  
Hydrobromic Acid ◽  
Methoxy Group ◽  
Methylene Chloride ◽  
Thiourea Dioxide ◽  
Boron Tribromide

The reaction of several substituted o- nitronitrosobenzenes with O- and p- anisidine , and 2,4- dimethoxyaniline in acetic acid gives in good yield the corresponding enitroazobenzenes which are readily reduced with thiourea dioxide ( formamidinesulfinic acid) to the corresponding 2-(methoxypheny1)-2H-benzotriazoles, demethylation of which furnished the corresponding 2- (hydroxypheny1)-2H-benzotriazoles. Demethylation of the dimethoxy derivatives was best accomplished with boron tribromide in methylene chloride, the methoxy group located ortho to the benzotriazole ring being demethylated more readily than is the para-methoxy group. The reaction of enitroazobenzenes containing a methoxy group with hydrobromic acid in acetic acid results in cleavage of the azo bond and also partial bromination to give o- nitroaniline and some of its brominated derivatives.

Determination of chemical shifts in 6-condensed syringylic lignin model compounds

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lucas Lagerquist ◽  
Jani Rahkila ◽  
Patrik Eklund
Keyword(s):  
Chemical Shift ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Model Compounds ◽  
Correlation Peak ◽  
Lignin Model Compounds ◽  
Benzylic Alcohols ◽  
Lignin Model ◽  
C Nmr

Abstract A small library of 6-substituted syringyl model compounds with aliphatic, carboxylic, phenylic, benzylic alcohols and brominated substituents were prepared. The influence of the substituents on the chemical shifts of the compounds was analyzed. All of model compounds showed a characteristic increase in the 13C NMR chemical shift of the methoxy group vicinal to the substitution. This 13C NMR peak and its corresponding correlation peak in HSQC could potentially be used to identify 6-condensation in syringylic lignin samples.

scholarly journals Leaving Group Ability in Nucleophilic Aromatic Amination by Sodium Hydride–Lithium Iodide Composite

Synthesis ◽  
2019 ◽  
Vol 52 (03) ◽  
pp. 393-398
Author(s):  
Jia Hao Pang ◽  
Derek Yiren Ong ◽  
Kohei Watanabe ◽  
Ryo Takita ◽  
Shunsuke Chiba
Keyword(s):  
Nucleophilic Substitution ◽  
Methoxy Group ◽  
Sodium Hydride ◽  
Lithium Iodide ◽  
Substitution Reactions ◽  
Computational Approaches ◽  
Nucleophilic Substitution Reactions ◽  
Leaving Group ◽  
Leaving Group Ability

The methoxy group is generally considered as a poor leaving group for nucleophilic substitution reactions. This work verified the superior ability of the methoxy group in nucleophilic amination of arenes mediated by the sodium hydride and lithium iodide through experimental and computational approaches.

scholarly journals Combined directed ortho-zincation and palladium-catalyzed strategies: Synthesis of 4,n-dimethoxy-substituted benzo[b]furans

2011 ◽  
Vol 7 ◽  
pp. 1255-1260 ◽  
Author(s):  
Verónica Guilarte ◽  
M Pilar Castroviejo ◽  
Estela Álvarez ◽  
Roberto Sanz
Keyword(s):  
Methoxy Group ◽  
Sonogashira Coupling ◽  
Furan Derivatives ◽  
Iodination Reaction ◽  
Palladium Catalyzed

A new route to regioselectively dialkoxy-functionalized benzo[b]furan derivatives has been developed from 3-halo-2-iodoanisoles bearing an additional methoxy group, which have been accessed through an ortho-zincation/iodination reaction. Two palladium-catalyzed processes, namely a Sonogashira coupling followed by a tandem hydroxylation/cyclization sequence, give rise to new and interesting dimethoxy-substituted benzo[b]furans.

The Effects of the Electron-Donating Methoxy Group on the Photoisomerization of 4-Methyl-2,4,6-triaryl-4H-thiopyran-1,1-dioxides.

ChemInform ◽  
2006 ◽  
Vol 37 (12) ◽  
Author(s):  
Hooshang Pirelahi ◽  
Farnaz Jafarpour ◽  
Ghasem Rezanejadebardajee ◽  
Javad Amanishamsabaad ◽  
Arash Mouradzadegun
Keyword(s):  
Methoxy Group

scholarly journals Molecular modelling, synthesis and antitumour activity of carbocyclic analogues of netropsin and distamycin--new carriers of alkylating elements.

2000 ◽  
Vol 47 (1) ◽  
pp. 23-35 ◽  
Author(s):  
D Bartulewic ◽  
A Markowska ◽  
S Wołczyński ◽  
M Dabrowska ◽  
A Rózański
Keyword(s):  
Molecular Modelling ◽  
Methoxy Group ◽  
Antitumour Activity ◽  
National Laboratory ◽  
Data Bank ◽  
Brookhaven National Laboratory ◽  
Ortho Position ◽  
Standard Cell ◽  
New Compounds ◽  
Mcf 7

A series of netropsin and distamycin analogues was synthesised and investigated by molecular modelling. The lowest-energy conformations of four carbocyclic lexitropsins, potential carriers of alkylating elements, were obtained using the HyperChem 4.0 program, and compared with the DNA-lexitropsin crystal structures from the Brookhaven National Laboratory Protein Data Bank. A method for synthesis of carbocyclic lexitropsins was elaborated, with the use of a nitro group or azobenzene as precursors for the aromatic amino group. The influence of methoxy group in ortho position with respect to amide groups on the activity of the new compounds was investigated. All of the compounds tested showed high antitumour activity in the standard cell line of mammalian tumour MCF-7.

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