ARYLPYRIDINES: PART I. ORIENTATION IN THE REACTION OF PHENYLLITHIUM WITH SOME 3-SUBSTITUTED PYRIDINES

1960 ◽  
Vol 38 (6) ◽  
pp. 761-771 ◽  
Author(s):  
R. A. Abramovitch ◽  
Giam Choo Seng ◽  
A. D. Notation
Keyword(s):  
Quantitative Analysis ◽  
Vapor Phase ◽  
Steric Effect ◽  
Main Product ◽  
Phenyl Substituent ◽  
First Case ◽  
Substituted Pyridines ◽  
Crude Mixture ◽  
Nucleophilic Reagents

The orientation of the entering phenyl substituent in the addition of phenyllithium to 3-picoline and nicotine has been studied. In the first case the main product was 3-methyl-2-phenylpyridine together with a small amount of 5-methyl-2-phenylpyridine; the ratio of the isomers being 19:1. The structure of the isomers was established by oxidation to the corresponding phenylnicotinic acids, by infrared and n.m.r. spectroscopy. Quantitative analysis of the crude mixture of isomers was effected by vapor phase chromatography. Phenylation of nicotine gave 2-phenyl- and 6-phenyl-nicotine in the ratio of 1:1. Separation of the isomers was effected by preparative vapor phase chromatography and their orientation established as above. Evidence that the 3-substituent exerts an appreciable steric effect in the end product of the addition is presented. The results are taken to mean that addition of phenyllithium, and probably of other nucleophilic reagents, to 3-substituted pyridines occurs preferentially at the 2-position but the 3-substituent, if sufficiently bulky, may exert a steric effect resulting in appreciable addition at the 6-position also.

AROMATIC SUBSTITUTION: PART I. THE REACTION OF PHENYLLITHIUM WITH 3-ALKYLPYRIDINES. STERIC EFFECT AND QUANTITATIVE ANALYSIS OF ISOMER RATIOS

1962 ◽  
Vol 40 (2) ◽  
pp. 213-219 ◽  
Author(s):  
R. A. Abramovitch ◽  
Choo-Seng Giam
Keyword(s):  
Quantitative Analysis ◽  
Vapor Phase ◽  
Alkyl Group ◽  
Steric Effect ◽  
Main Product ◽  
Methyl Ethyl ◽  
Aromatic Substitution

No 4-phenylpyridine is formed in the reaction of phenyllithium with pyridine. When phenyllithium reacts with a 3-alkylpyridine the main product is the 3-alkyl-2-phenylpyridine if the alkyl group is methyl, ethyl, or isopropyl, but it is the 5-alkyl-2-phenylpyridine when the substituent is t-butyl. Methods are described for the separation and quantitative analysis of mixtures of 3-alkyl- and 5-alkyl-2-phenylpyridines using vapor phase chromatography. The results are discussed briefly and possible explanations of the observed orientations are mentioned.

Quantitative Analysis of Trace Metals in Silicon Nitride Films by a Vapor Phase Decomposition/Solution Collection Approach

2000 ◽  
Vol 147 (4) ◽  
pp. 1499 ◽  
Author(s):  
G. Vereecke ◽  
M. Schaekers ◽  
K. Verstraete ◽  
S. Arnauts ◽  
M. M. Heyns ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Silicon Nitride ◽  
Trace Metals ◽  
Vapor Phase ◽  
Phase Decomposition ◽  
Silicon Nitride Films

DEVELOPMENT OF A METHOD FOR DETERMINATION OF ALCOHOLS IN FORMATION WATER

2019 ◽  
pp. 30-36
Author(s):  
I.V. Mukhina ◽  
E.D. Gribovа ◽  
E.A. Denisova ◽  
D.A. Dyagil ◽  
A.V. Agaltsova
Keyword(s):  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Organic Compounds ◽  
Vapor Phase ◽  
Produced Water ◽  
Formation Water ◽  
Polar Organic Compounds ◽  
Salting Out ◽  
Polar Components

In this paper we propose an algorithm for the analysis of monohydric aliphatic alcohols in formation water, which makes it possible to eliminate the influence of non-polar components of oil. A sample of produced water is passed through a sorbent, removing non-polar organic compounds interfering with the analysis. In the resulting eluate add salting out agent and conduct a quantitative analysis of alcohols in the vapor phase by gas chromatography.

Caveat Regarding the Use of Substituent Parameters in Statistical Analyses of Molecular Properties. II. Case Study : 13 N.M.R. of 2-Substituted Pyridines and Monosubstituted Benzenes

1989 ◽  
Vol 42 (9) ◽  
pp. 1493 ◽  
Author(s):  
IB Cook
Keyword(s):  
Quantitative Analysis ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Bond Polarity ◽  
Bond Polarizability ◽  
Substituted Pyridines ◽  
Monosubstituted Benzenes ◽  
High Degree ◽  
Benzene Series

Carbon-13 n.m.r. substituent chemical shifts of equivalent positions on monosubstituted benzenes and 2-substituted pyridines are analysed by multiple linear regression on combinations of a field, resonance, electronegativity and three polarizability parameters. The ortho and meta positions of the 2-pyridine and benzene series are poorly described by σF and σR parameters, but a much improved fit is obtained when σx and/or a bond polarizability parameter σ α,(C-X) are included. The mechanism of shift formation differs markedly between the two systems when the C2, C4 and C6 positions on pyridine are compared with the geometrically equivalent positions on benzenes. Owing to the high degree of interdependence between the four substituent effects, quantitative analysis proved to be impossible. However, use of subsets of substituents with three of the four parameters approximately orthogonal enabled the mechanism to be deduced in most cases. It is postulated that the differences between the pyridine and benzene systems arises from perturbation of the C-N bond polarity. A mechanism to explain the results is presented.

Determination of the activity coefficients of methanol and ethanol in benzene solutions by gas chromatography

1967 ◽  
Vol 45 (24) ◽  
pp. 3089-3095 ◽  
Author(s):  
Peter Pollak ◽  
G. C. B Cave
Keyword(s):  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Activity Coefficients ◽  
Vapor Phase ◽  
Chromatographic Method ◽  
Low Concentrations ◽  
Gas Chromatographic Method

A rapid gas-chromatographic method is described for the quantitative analysis of the equilibrium vapor phase over a solution. A vapor pump has been designed for the purpose and is described. The method should be particularly useful at low concentrations of volatile solutes, alone or in mixtures. As an example of the application of the method, the vapor concentrations of methanol and of ethanol over benzene solutions at 25 °C have been measured. The precision of the data is also reported. The activity coefficients of the alcohols in the benzene solutions were calculated.

scholarly journals Phototransposition chemistry of pyridine and substituted pyridines in the vapor phase

ARKIVOC ◽  
2018 ◽  
Vol 2018 (6) ◽  
pp. 254-271
Author(s):  
James W. Pavlik ◽  
Naod Kebede
Keyword(s):  
Vapor Phase ◽  
Substituted Pyridines

scholarly journals Low Temperature Decomposition of Polystyrene

2020 ◽  
Vol 10 (15) ◽  
pp. 5100
Author(s):  
Hideki Kimukai ◽  
Yoichi Kodera ◽  
Koushirou Koizumi ◽  
Masaki Okada ◽  
Kazunori Yamada ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Decomposition ◽  
Quantitative Analysis ◽  
Main Product ◽  
Basic Structure ◽  
Industrial Area ◽  
Decomposition Kinetics ◽  
Natural Environments ◽  
Selected Ion Monitoring ◽  
Temperature Decomposition

Styrene oligomers (SOs), of styrene (styrene monomer, SM), 1,3-diphenylpropane (styrene dimer, SD1), 2,4-diphenyl-1-butene (styrene dimer, SD2) and 2,4,6-triphenyl-1-hexene (styrene trimer, ST), had been detected in the natural environments far from industrial area. To confirm SOs formation through thermal decomposition of polystyrene (PS) wastes in the nature, purified polystyrene (SO-free PS) has been shown to decompose at 30 to 150 °C. The SO ratio of SM:SD:ST was about 1:1:5 with ST as the main product. Mass spectrometry with selected ion monitoring was used for the quantitative analysis of the trace amounts of SOs. The rate of PS decomposition was obtained as k(year−1)=5.177 exp(−5029/T(K)) based on the amount of ST. Decomposition kinetics indicated that not only does drifting lump PS break up into micro/nano pieces in the ocean, but that it also subsequently undergoes degradation into basic structure units SO. According to the simulation at 30 °C, the amounts of SOs in the ocean will be over 400 MT in 2050.

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