N-alkyl Compounds Research Articles

Electronic coupling through saturated hydrocarbon bridges

Through-bond (TB) coupling between the chromophores of a series of polynorbornyldienes 1( n ), α,ω-diethynyl[ n]staffanes 2( n ), α,ω-divinyl[ n]staffanes 3( n ), and a series of all-trans, n-alkyl compounds, X-(CH 2) l -X, where X=H 2CC 4( n ), HCC 5( n ), OH 6( n ), SH 7( n ), and planar NH 2 8( n ), have been investigated using ab initio MO theory, with the 3–21G basis set, in the Koopmans' theorem approximation. A natural bond orbital (NBO) analysis of the n-alkyl compounds, 4( n )– 8( n ), shows that much of the variation of the TB electronic coupling among the different series is governed by the self-energy of the chromophore orbitals. This conclusion was surmised from “tuning” experiments in which the chromophore self-energies in the NBO Fock matrix of one system are replaced by those of a different chromophore. Analysis of the TB pathways shows that the tight binding (nearest neighbor) model is grossly inadequate in explaining TB orbital interaction behavior, and that intrabridge interactions that skip over one or more bridge bonds also need to be included for a realistic analysis. In addition, model Hamiltonian matrices, constructed using NBO Fock matrix elements, demonstrate the importance of “retracing” pathways.

Mesomorphic properties of some 1,4,8,11,15,18,22,25-octa-alkoxymethylphthalocyanines

Abstract The mesophase behaviour of a number of non-peripherally octa-substituted phthalocyanine derivatives has been studied by optical microscopy, differential scanning calorimetry (DSC) and X-ray diffraction. A homologous series of straight chain alkoxymethyl derivatives has exhibited both rectangular and hexagonal columnar mesophases, with the rectangular phases being favoured by the shorter chains. Two branched chain derivatives were found to give rectangular columnar phases at room temperature. A detailed analysis of the X-ray data has shown some differences from the analogous n-alkyl compounds. It has been deduced that the increased polarizability and flexibility of the ether linkage allows the disc-like molecules to approach more closely face to face with correspondingly thicker columns.

Extraction and identification of nitrile compounds in rundle shale oil

The nitriles in Rundle shale oil were hydrolyzed under alkaline conditions, extracted as the carboxylic acids and subsequently identified as the corresponding methyl esters. The major components were a series of n-alkyl compounds. At least three other series were present: two olefinic and one phenyl-alkyl. Minor components were mainly monoaromatic. Several compounds not observed previously in shale oil were identified.

Comparisons in EAG Response to n-Alkyl Compounds between the Fruit- and Pinaceae-Feeding Type of Yellow Peach Moth, Conogethes punctiferalis (GUENEE) : Lepidoptera : Pyralidae

EAG responses to 90 n-alkyl compounds, with different functional groups and some homologues, were compared between the two types of the yellow peach moth, Conogethes punctiferalis (GUENEE), fruit-feeding type (FFT) and Pinaceae-feeding type (PFT). Females of both types responded clearly to C5 or C6 compounds in all three series of alkanol, alkanal, and alkanoic acid while both males showed prominent bimodal response with C5 or C6 and C9 compounds in aldehyde. The antennae of both sexes in each type more significantly responded to n-hexanal taan to the corresponding alcohol and acid. The FFT antennae were twice as sensitive to n-hexanol and n-hexanal, and 1.5 times more to n-hexanoic acid than the PFT antennae. Females of both types were more sensitive to n-hexanoic acid than the males, particularly in FFT, but no significant difference was observed with n-hexanol and n-hexanal. The threshold dosages of n-hexanol, n-hexanal and n-hexanoic acid to both types were not significantly different, and were within 5×10-4μl to 1×10-3μl. The EAG responses of both types to ester homologues were unimodal and bimodal in female and male, respectively, similar to those to aldehyde homologues. From these differences in EAG response and with reference to the morphological and biological differences reported earlier, we conclude that the two types are separate species.

Kinetic study of the solvolysis reactions of 1-aryl-3-acetoxymethyl-3-alkyltriazenes: evidence for iminium ion intermediates and the S N1 mechanism

The first-order rate constants of the reactions of acetoxymethyltriazenes with nucleophiles have been measured. Acetoxymethyltriazenes undergo hydrolysis in phosphate buffer to give the corresponding arylamines, presumably via the hydroxymethyl- and monomethyl-triazenes. The acetoxymethyltriazenes undergo solvolysis in alcohols and in mixtures of alcohols and other solvents; the rate of solvolysis has been correlated with the Grunwald–Winstein parameter (Y) for solvent ionising power, thus supporting the hypothesis of an SN1 mechanism and the intermediate formation of iminium ions during the solvolysis. The hypothesis is further supported by the non-common-ion effect; the presence of lithium chloride in the solvent greatly increases the rate of reaction, whereas lithium acetate causes a slight decrease in rate, attributable to a common-ion effect. Reaction of the acetoxymethyltriazene with sodium azide in aqueous acetone affords the α-azidomethyltriazene (a new type of triazene not previously reported) and provides supporting evidence for the iminium ion hypothesis. On the other hand, the acetoxymethyltriazene did not react with neat ethanethiol, providing further evidence for an SN1 mechanism; and SN2 reaction would be expected to proceed more quickly in the thiol than in the alcohol. It is shown that hydroxymethyltriazenes do not react via iminium ions and that functionalisation to a derivative such as the acetate is necessary for iminium ion generation. The implications of these results for the metabolism of xenobiotic N-alkyl compounds are discussed.

The generation of potentially toxic, reactive iminium ions from the oxidative metabolism of xenobiotic N-alkyl compounds

The generation of potentially toxic, reactive iminium ions from the oxidative metabolism of xenobiotic N-alkyl compounds

Protection of primary amines as N-substituted 2,5-dimethylpyrroles

Protection of a primary amine group is achieved by incorporating it into an N-substituted 2,5-dimethylpyrrole system. The method affords protection against strong bases and nucleophiles, heating with concentrated alkali, standard mineral acid work-up conditions, and various other reagents.Phenyl-, pyridyl-, thiazolyl-, and alkyl-amines have been studied. All give trisubstituted pyrroles in high yield (>80%) by reaction with hexane-2,5-dione. The pyrroles from the first three types are stable to storage; even the N-alkyl compounds can be used without difficulty. Regeneration of the amine group, by treatment with hydroxylamine hydrochloride, is efficient (ca. 80% yield) with the phenyl, pyridyl, and alkyl compounds but less satisfactory (60–65% generally but down to 25% in two cases) with the thiazolyl derivatives.

Fourier transform NMR pulsed-gradient spin—echo (FT-PGSE) self-diffusion measurements of solubilization equilibria in SDS solutions

Solubilization equilibria for homologous series of alcohols, methyl ketones, aromatics, and crown ethers with SDS micelles in D 2O solution at 25°C were determined. The measurements are based on multicomponent self-diffusion studies through an improved version of a Fourier transform NMR pulsed-gradient spin-echo technique. As expected, the degree of solubilization increases strongly with the number of carbon atoms in the solubilizate alkyl chains, corresponding to an increment in the standard free energy for transfer of solubilizate molecules from the aqueous to the micellar phase (ΔG p o) of ≈ −2.6 kJ mole −1 for each −CH 2− group. Hydrocarbon chain branching in the solubilizate molecules decreases the degree of solubilization, as compared to conditions for n-alkyl compounds. Crown ether solubilization is found to increase strongly with ring size. Comparative studies with lauryltrimethylammonium bromide micelles do not show this trend, suggesting that the effect can be ascribed to the sodium binding capability of the larger crown ethers, and that crown ethers are “solubilized” at the SDS micellar surface.

The effect of co-ordination on the rate of methoxydechlorination of 5-chloro-1,10-phenanthroline

The kinetics of methoxydechlorination of 5-chloro-1,10-phenanthroline when co-ordinated to NiII, RuII, and OsII have been studied in dimethyl sulphoxide–methanol (89.9 : 10.1 w/w). In all cases studied there is a considerable enhancement of reactivity which bears more relationship to the total charge on the complex than it does to the nature of the central metalion. The following complexes have been examined (relative rates at 25°C in parentheses: [Ru(5-Cl-phen)3]2+(5 420), [Ni(5-Cl-phen)3]2+(3160), [Os(5-Cl-phen)3]2+(2 680), [Os(5-Cl-phen)2(acac)]+(353); [Os(5-Cl-phen)2(ox)]°(95), and 5-Cl-phen (1). This is in contrast to the N-alkyl compounds which add methoxide in the 2-position and are deactivated towards methoxydechlorination.

Potential Long Acting Opiate Antagonists: Preparation, Pharmacological Activity, and Opiate-Receptor Binding of N-Substituted 2′-Hydroxy-5-methyl-9α-propyl-6,7-benzomorphans

A homologous series of N-substituted 2'-hydroxy-5-methyl-9 alpha-propyl-6,7-benzomorphans (hydrogen to octyl inclusive, allyl, and cyclopropylmethyl) was prepared. In contradistinction to the normetazocine, normorphine, and (-)-3-hydroxymorphinan series, the N-pentyl and N-hexyl derivatives do not have the analgesic potency of the parent N-methyl compound; instead, they are narcotic antagonists with a long duration of action. All of the N-substituted 9 alpha-propylbenzomorphans, except for methyl, heptyl, and octyl, have antagonist activity. The receptor binding constants of the N-alkyl compounds are uniformly two- to threefold lower than those of the N-substituted normetazocines.

Dielectric relaxation of 1-alkenes

Dielectric constants and losses have been measured for 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, and 1-octadecene as pure liquids at up to 10 frequencies between 1 and 140 GHz at 25°C. The mean relaxation times, τ0, and viscosities, η, increase significantly with increasing chain length; however, the parameter τ0/η reaches a maximum for 1-dodecene and then decreases with increasing chain length. The results are compared with those obtained for other n-alkyl compounds containing a polar end group.

Criteria for distinguishing biogenic and abiogenic amino acids--preliminary considerations.

Criteria to determine the mode of origin of amino acids can be established by consideration of their structure, enantiomeric distribution, composition, and relative abundance. A population of dominantly protein amino acids with one enantiomeric configuration most likely had a biological origin. Biological amino acids do racemize, however, so the absence of optical activity would not rule out the possibility that the amino acids in a racemic mixture were originally synthesized biologically. For racemic amino acids, therefore, structure, composition and relative abundance become important in ascertaining the origin of these compounds. Abiotically synthesized amino acids have a population composed of both protein and nonprotein structures present as racemic mixtures. N-alkyl compounds are common and α-β- and γ-amino carboxylic acids are expected. Also most amino acid isomers with four or less carbon atoms should be present in an abiotically derived mixture.

The Reaction of some Isothiazolium Salts with Sulfur in Pyridine

A variety of N-methyl and N-phenylisothiazolium salts has been synthesized and treated with sulfur in boiling pyridine. The products have been examined by chromatography and their structures determined. While 5-unsubstituted isothiazolium salts appear to give the corresponding isothiazoline-5-thiones, 3-unsubstituted salts give either the corresponding isothiazoline-3-thiones if the nitrogen is alkyl substituted, or 1,2-dithiole-3-imines if the nitrogen is aryl substituted. N-Alkyl compounds also give dealkylated products, and dithiolethiones are also found. The initial stages in the reaction appear to involve deprotonation of the isothiazolium salt.

The combination band of the methyl group torsion and antisymmetrical stretching frequency—III. The ethyl halides and other n-alkyl compounds

A large number of combination levels of the methyl group torsion and CH stretching frequencies have been determined for ethyl chloride, bromide, and iodide. A torsional combination band could also be identified in the infrared spectra of several other n-alkyl compounds, and an average value of 225 ± 5 cm−1 for the torsional transitions at about 35°C has been calculated (liquid state). The CH stretching and deformation fundamentals of the ethyl halides and 1-chloropropane have been reassigned, and the results are indicating that the symmetrical CH3 stretching vibration of n-alkyl compounds occurs between 2940 and 2910 cm−1.

医薬品の生体内変化に関する研究(第58報) : 4-ブチルアミノアンチピリンの生体内変化について

In the metabolic study of butyl aryl ethers in vivo, it has been shown in this laboratory that dealkylation is only minor and penultimate hydroxylation is the major one. In connection with this study, metabolism of 4-butylaminoantipyrine was investigated to learn whether it also undergoes the penultimate hydroxylation rather than the dealkylation of butyl chain. Contrary to this expectation, the major pathway of this drug was found to be dealkylation in all of the animals tested (rabbits, guinea pigs, mice, and rats), excreting 4-aminoantipyrine and its acetylated metabolite, 4-acetamidoantipyrine, as the main metabolites. However, it has also been recognized that there is a small amount of other urinary metabolite. The structure of this minor metabolite has been identified as 4-(2-butenylamino)antipyrine by the comparison with the authentic sample chemically synthesized. Since it seems very likely that this metabolite may be formed from the penultimate hydroxylated metabolite by dehydration, the presnet study would support the hypothesis that, as in C- and O-alkyl compounds, the penultimate hydroxylation takes place also in N-alkyl compounds if they have a considerably long alkyl chain such as butyl group.

Ring Nonplanarity and Aromaticity in Porphyrins. Nuclear Magnetic Resonance Spectra of Etioporphyrin II and Its N-Alkyl Compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRing Nonplanarity and Aromaticity in Porphyrins. Nuclear Magnetic Resonance Spectra of Etioporphyrin II and Its N-Alkyl CompoundsWinslow S. Caughey and Peter K. IberCite this: J. Org. Chem. 1963, 28, 1, 269–270Publication Date (Print):January 1, 1963Publication History Published online1 May 2002Published inissue 1 January 1963https://doi.org/10.1021/jo01036a538RIGHTS & PERMISSIONSArticle Views74Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (258 KB) Get e-Alerts Get e-Alerts