Alkyl-substituted Pyridines Research Articles

ChemInform Abstract: REACTIVITY MODEL FOR THE MENSCHUTKIN REACTION. METHYLATION OF ALKYL‐SUBSTITUTED AND HETEROSUBSTITUTED PYRIDINES

Chemischer InformationsdienstVolume 15, Issue 23 Physical Organic Chemistry ChemInform Abstract: REACTIVITY MODEL FOR THE MENSCHUTKIN REACTION. METHYLATION OF ALKYL-SUBSTITUTED AND HETEROSUBSTITUTED PYRIDINES J. C. SCHUG, J. C. SCHUGSearch for more papers by this authorJ. W. VIERS, J. W. VIERSSearch for more papers by this authorJ. I. SEEMAN, J. I. SEEMANSearch for more papers by this author J. C. SCHUG, J. C. SCHUGSearch for more papers by this authorJ. W. VIERS, J. W. VIERSSearch for more papers by this authorJ. I. SEEMAN, J. I. SEEMANSearch for more papers by this author First published: June 5, 1984 https://doi.org/10.1002/chin.198423044AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume15, Issue23June 5, 1984 RelatedInformation

Determination of polar compounds in Rundle shale oil

The acidic and basic components of three distillate fractions (light, middle and heavy) of shale oil from the Rundle (Queensland, Australia) deposit were selectively extracted. Capillary gas chromatography/mass spectrometry was used to identify individual polar components. The major nitrogen-containing polar compounds in the light fraction were alkyl-substituted pyridines, and substituted quinolines were more abundant in the middle and heavy fractions. Significant quantities of pyrrole derivatives were also identified. Small quantities of anilines and benzoquinolines made up the remainder of the bases. The oxygen-containing compounds were mainly phenolic in nature; alkyl-substituted phenols were the major components, but significant quantities of naphthols and traces of fluorenols were identified.

Study of Fischer-Tropsch synthesis over [formula omitted]: Reactive scavenging with pyridine and cyclohexene

The synthesis of hydrocarbons from H 2 and CO was studied on a silica-supported Fe catalyst. The synthesis was carried out at 1.54 atm and 200 to 255 °C in a differential reactor. Conversion of CO never exceeded 2%. The working catalyst is achieved by transforming Fe 2O 3 into a mixture of Fe 3O 4, bulk carbides, and iron under synthesis conditions. Synthesis product distributions and the rate of methane formation are reported. Trends in CO 2 formation and the presence of cyclic hydrocarbons, saturated and unsaturated, suggest the presence of some Fe 3O 4 at the catalyst surface. Cyclohexene addition to the feed generates low concentrations of alkyl-substituted cyclohexenes and cyclohexanes consistent with reported scavenging studies over Ru. Pyridine addition to the feed generates alkyl-substituted pyridines. The results suggest that the scavengers react with species involved in chain propagation.

An inverse reactivity-selectivity relationship. Kinetic nitrogen isotope effects on methyl transfer to pyridines

This paper reports that values of the /sup 14/N//sup 15/N rate constant ratio for methyl transfer to alkyl-substituted pyridines decrease (become more inverse) as CH/sub 3/X becomes more reactive and may also decrease as the pyridine becomes more reactive. These changes in K/sub 14//K/sub 15/ demonstrate increasing selectivity for /sup 15/N in preference to /sup 14/N as reactivity increases and thus are in violation of the reactivity-selectivity principle. However, these observed changes in K/sub 14//K/sub 15/ are consistent with a very recent prediction that such ''anti-Hammond'' effects should result from changes in quantum mechanical mixing of configurations in the transition state and should dominate the more familiar effects of structural perturbations of the free energy surface.

Measurement of surface acid site concentration by carbon-13 NMR

A method of measuring simultaneously the concentration of surface proton and Lewis acid sites is proposed. The method is based on 13C NMR spectroscopy of a suitable adsorbed amine. An investigation of several alkyl-substituted pyridines shows 4-ethylpyridine to be the most satisfactory choice. The method is tested on a silica-alumina cracking catalyst, and found to give good results for total acid concentration. Decomposition of the total acid into proton and Lewis acids requires a higher precision of measurement than presently achieved, but appears possible with existing instruments. Application of the method to silica-alumina with added water shows that the catalyst behavior in the presence of water is more complicated than assumed by previous workers.

Origin of alkyl-substituted pyridines in food flavor: formation of the pyridines from the reaction of alkanals with amino acids

Origin of alkyl-substituted pyridines in food flavor: formation of the pyridines from the reaction of alkanals with amino acids

Electrochemical fluorination. Part I. Electrochemical fluorination of alkyl-substituted pyridines

Electrochemical fluorination of various alkyl-substituted pyridines affords the corresponding perfluoro-(N-fluoroalkylpiperidines) in yields [pyridine (8%), 2-methylpyridine (13%), 3-methylpyridine (2%), 2-ethylpyridine (1%), 2,4-dimethylpyridine (11%), 2,6-dimethylpyridine (26%), 3,5-dimethylpyridine (2%), and 2,4,6-trimethylpyridine (10%)] which depend to a large extent on the position and number of alkyl substituents. Electrochemical fluorination provides a useful route to fluorocarbons of structures corresponding to the original carbon skeletons in the alkylpyridine, together with related fluorocarbons produced by chain degradation. The production of other fluorocarbons reveals that carbon skeleton rearrangement can occur, but to only a minor extent, during electrochemical fluorination.

The prototropic rearrangement of secondary propargylic amines

Secondary and tertiary propargylic amines of types 3 and 4 were synthesized. On prototropic isomerization amines 3a-f isomerized to α,β-unsaturated aldimines of type 6 while 3g and 3h isomerized to conjugated aldimines 18 and 19 respectively. The diyne-diamine 27 isomerized to a fully conjugated diene-diimine 28. Amine 3i on treatment with base yielded aniline. Alkyl-substituted dipropynylamines 29b-d were prepared and on prototropic isomerization aromatized to alkyl-substituted pyridines. The unsubstituted dipropynylamine 29a however underwent under the above conditions two types of skeletal rearrangement to yield nitriles 44a and b in high yield and oximes 45a and b in low yield.

Boron-11 chemical shifts in the determination of donor-acceptor strengths—V. The interaction of diethyl phenylboronate with pyridine and some alkyl-substituted pyridines

Boron-11 chemical shifts in the determination of donor-acceptor strengths—V. The interaction of diethyl phenylboronate with pyridine and some alkyl-substituted pyridines

Effects of π-electron densities and solvent on proton resonances of alkyl-substituted pyridines and benzenes

Proton chemical shifts in equimolar solutions of monoalkyl-substituted benzenes and 4-alkyl-substituted pyridines have been studied in various solvents. Shift variations have been correlated with the dielectric function (ε– 1)(ε+ 1) where ε is the dielectric constant of the solvent. Alkyl groups were found to have comparable substituent effects on proton resonances of the pyridine and phenyl rings. Salts of the pyridinium and N-alkylpyridinium ions were studied in deuterium oxide solutions. The ring-proton and alkyl-proton shifts for each salt and the parent pyridine have been used to deduce relative π-electron densities which have been compared with those calculated with a Hückel Molecular Orbital (HMO) programme. Additivity effects for proton, methyl, and ethyl substituents on the shifts for the ring protons are evaluated. The effects of solvent interactions upon shifts and line-widths for the salts are discussed.