Showing papers on "Piperidine published in 1973"
TL;DR: In this paper, the authors studied the kinetics of pyridine hydrogenation at high hydrogen pressures on a Mo-Al oxide and a Co-MoAl oxide catalyst and found that the rate equation was r = kPpyrPH2n/Ppyro, in which n is 1.5 at 300 and 375 °C and 1.0 at 250 °C.
54 citations
53 citations
Patent•
30 Jul 1973
TL;DR: Novel esters of menthol and heterocyclic carboxylic acids such as 2-pyrrolidone-5-carboxyric acid, pipecolic acid, nipecotic acid, and isonipe cotic acid can be incorporated into products for oral use, such as a dentifrice, to give an effect of freshness which last longer than that of the menthol as discussed by the authors.
Abstract: Novel esters of menthol and heterocyclic carboxylic acids such as 2-pyrrolidone-5-carboxylic acid, pipecolic acid, nipecotic acid and isonipecotic acid can be incorporated into products for oral use, such as a dentifrice, to give an effect of freshness which lasts longer than that of menthol.
46 citations
44 citations
38 citations
TL;DR: In this paper, a reasonable mechanism was proposed to explain the octahedral stereochemistry of trisdithiocarbamates of arsenic and antimony with pyrrolidine, piperidine, diisobutylamine and dibenzylamine.
37 citations
TL;DR: In this paper, the magnetic moments of the bis(β-ketoenolates)cobalt(II) of piperidine, piperazine, methylpiperazine and morpholine have been measured.
33 citations
TL;DR: It is concluded that piperidine can mimic the acetylcholine action on H-cells and may participate in signal processing mechanisms in the nervous system of this species by any of the actions reported here, if it were released in sufficient quantities.
31 citations
28 citations
TL;DR: The carbon-13 magnetic resonance spectra of three diastereoisomers of 1,2,5-trimethyl-4-phenylpiperidin-4ol and their esters and corresponding hydrochlorides have been determined in deuterochlorof...
Abstract: The carbon-13 magnetic resonance spectra of three diastereoisomers of 1,2,5-trimethyl-4-phenylpiperidin-4-ol and their esters and corresponding hydrochlorides have been determined in deuterochlorof...
23 citations
TL;DR: In this paper, the structures of these complexes have been discussed from their NH stretching frequencies, i.e. 1:1 and 1:2 mole ratios in amines to halogens.
TL;DR: In this article, a series of new compounds of the form (aminemanganesephthalocyanine)2O with N-methylimidazole, 3-picoline and piperidine are reported.
Patent•
17 Jul 1973TL;DR: New piperidine derivatives and esters and amides of substituted (piperidinyl-4) acetic acid are used as stabilisers for polymers, especially for polyolefines as discussed by the authors.
Abstract: New piperidine derivatives and in particular esters and amides of substituted (piperidinyl-4) acetic acid are used as stabilisers for polymers, especially for polyolefines.
TL;DR: In this article, the stereoselectivity of the telomers and the effect of telogens in the anionic telomerizations of isoprene with secondary amines were investigated.
Abstract: The stereoselectivity of the telomers and the effect of the telogens in the anionic telomerizations of isoprene with secondary amines were investigated. Dimethyl-, diethyl-, di-n-propy-1, diisopropyl-, and methylphenyl-amines, pyrrolidine, morpholine, and piperidine were used as the telogens. The ratio of N,N-dialkyl(3,7-dimethyl-2,6-octadienyl)amine(2A) to N,N-dialkyl(2-isopropenyl-5-methyl-4-hexenyl)amine(2B), which were obtained in these reactions, was varied with the sort of secondary amines, the yield of the telomers was found to be dependent on the acidity of the secondary amines. Moreover, 2A, which was the main component of the n=2 telomers, was confirmed to have a cis-configuration—that is, N,N-dialkylnerylamine. However, the n=1 telomer of myrcene with secondary amine was N,N-dialkylgeranylamine. These results were interpreted in terms of the stability of the cyclic intermediate of the carbanions.
TL;DR: A series of complexes formed between transition metal ions and the stable free radicals 2,2,6,6- tetramethyl-4amino-4-caboxypiperidine-1-oxyl and glyoxal-bis has been prepared.
Abstract: A series of complexes formed between transition metal ions and the stable free radicals 2,2,6,6- tetramethyl-4-amino-4-caboxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-aminopiperidine-l -oxyl, 2,2,6,6-tetram ethyl-piperidine-l-oxyl and glyoxal-bis(2,2,2,6,6-tetramethyl-4-iminopiperidine-1- oxyl) has been prepared. The magnetic moments and the epr-spectra of the complexes have been investigated. Some of the complexes show a temperature dependent interaction between the radicalic nitroxyl groups of the ligands. By analysis of the epr-spectra in the solid state there was found in some cases an interaction between the metal ion and the unpaired electrons of the ligands.
TL;DR: In this article, the reaction of aryl isocyanates with enamino ketones, derived from acetylacetone and secondary amines such as piperidine and pyrrolidine, has been investigated.
Abstract: The reaction of aryl isocyanates with enamino ketones, derived from acetylacetone and secondary amines such as piperidine and pyrrolidine, has been investigated. At room temperature, enamino ketones react with phenyl, p-chlorophenyl and p-tolyl isocyanate to give 1:2 adducts, 3,5-diarylcarbamoyl derivative. In solution, these adducts exist in general as a mixture of two tautomers, 3-penten-2-one and 4-penten-2-one, the ratio depending on the solvent. Under reflux in benzene, the reaction of enamino ketones with phenyl isocyanate gives 4-amino-6-methyl-1-phenyl-5-phenylcarbamoylpyrid-2-one and its 3-phenylcarbamoyl derivative; the former is also obtained by heating the 1:2 adduct. On the other hand, 4-(1-pyrrolidinyl)-3-penten-2-one reacts with 1-naphthyl isocyanate to afford the 1:1 adduct, 5-(1-naphthylcarbamoyl)-4-penten-2-one.
Patent•
15 Oct 1973TL;DR: New piperidine derivatives and in particular 2-(piperidinyl-4')-ethyl-amines, -ethers and -esters are used as stabilisers for polymers, especially for polyolefines as discussed by the authors.
Abstract: New piperidine derivatives and in particular 2-(piperidinyl-4')-ethyl-amines, -ethers and -esters are used as stabilisers for polymers, especially for polyolefines.
TL;DR: In this article, a series of substituted piperidine nitroxides were generated in methylene chloride solution and their e.s.r. spectra were recorded from −100 to +35°.
Abstract: The advantages of e.s.r. spectroscopy for the investigation of conformational changes involving low energy barriers have been exploited in a detailed study of a series of substituted piperidine nitroxides. The nitroxides were generated in methylene chloride solution and their e.s.r. spectra were recorded from –100 to +35°. Detailed analysis of the spectra confirms that rapid chair–chair inversion takes places and computer simulation of the spectra obtained at different temperatures leads to accurate values for the associated activation parameters, ΔG‡, ΔH‡, and ΔS‡. The observed variation with temperature of the coupling constants of the C(2) and C(6) axial hydrogens is rationalised in terms of rapid inversion at the nitrogen atom.
Patent•
22 Feb 1973
TL;DR: The new 4-aminoquinoline derivatives show anti-malarial activity and, in some cases, shows one or more of the following activities: antiinflammatory activity, anti-hypertensive activity, antitrichomonal activity, inhibition of blood platelet aggregation, antiulcer activity and activity against allergic asthma as discussed by the authors.
Abstract: The disclosure describes new 4-aminoquinoline derivatives of general formula AND THEIR ACID ADDITION SALTS, WHERE X is a halogen atom or a trifluoromethyl group, Z is a hydrogen atom or a defined substituent, R is group of the formula -R3N-A-NR1R2 (II), where A in formula II is a chain of 1 to 5 methylene groups which may be substituted with alkyl, the ring in formula IIIa and IIIb is a piperidine or pyrrolidine ring that may be substituted with alkyl and R1, R2 and R3 represent hydrogen or certain defined substituents. The new 4-aminoquinoline derivatives show anti-malarial activity and, in some cases, shows one or more of the following activities: antiinflammatory activity, anti-hypertensive activity, antitrichomonal activity, inhibition of blood platelet aggregation, anti-ulcer activity and activity against allergic asthma.
Patent•
28 Dec 1973TL;DR: In this article, the formula of CH3 CH3 ANGLE HOO ¦ PARALLEL PARAL LEA LEA ¦ R3 N N N C-R4-C-O--M ANGLE R1R2 z where R1 and R2 are lower alkyl or form a cycloalkyl ring, R3 is hydrogen or a metal, and Z is an INTEGER of from 1 to 4, are good stabilizer against ACTINIC RADIATION.
Abstract: Compounds having the formula CH3 CH3 ANGLE HOO ¦ PARALLEL PARALLEL R3-N-N-C-R4-C-O--M ANGLE R1R2 z WHEREIN R1 and R2 are lower alkyl or form a cycloalkyl ring, R3 is hydrogen, alkyl, beta -methoxyethyl, alkenyl, propargyl, benzyl or alkyl substituted benzyl, R4 is alkylene, alkyl-thio-alkyl or alkyl-oxo-alkyl, M is hydrogen or a metal, and Z IS AN INTEGER OF FROM 1 TO 4, ARE GOOD STABILIZERS AGAINST ACTINIC RADIATION.
Patent•
28 Dec 1973TL;DR: In this article, the properties of polyolefins have been studied and it was shown that they are effectively stabilized with compounds having the formula ##SPC1## where R1 and R2 are lower alkyl or cycloalkyl, R3 is hydrogen, alkyls, β-methoxyethyl, alkenyl, propargyl, benzyl, or alkenynyl substituted benzyl.
Abstract: Organic materials, especially polyolefins, which are subject to ultraviolet light degradation, are effectively stabilized with compounds having the formula ##SPC1## Wherein R1 and R2 are lower alkyl or cycloalkyl, R3 is hydrogen, alkyl, β-methoxyethyl, alkenyl, propargyl, benzyl, or alkenyl substituted benzyl, and R4 is lower alkylene.
TL;DR: In this article, the preparation and properties of cis-and trans-4-substituted pipecolic (piperidine-2-carboxylic) acids are described, the substituents being methyl and t-butyl.
Abstract: The preparation and properties of cis- and trans-4-substituted pipecolic (piperidine-2-carboxylic) acids are described, the substituents being methyl and t-butyl. Their stereochemistry has been assigned according to the method of preparation and confirmed by 1H n.m.r. spectroscopy and epimersation experiments. The epimerisation experiments show that in the corresponding isomeric ethyl pipecolates the conformational preference of the ethoxy-carbonyl group is less than would be expected from comparison with cyclohexanecarboxylates. The difference is attributed to dipolar repulsions involving the axial ethoxycarbonyl group and the nitrogen lone pair. Using the hydrochlorides of the substituted pipecolic acids, measurements of the acidity of the ammonium group (pKa2) and the carboxy-group (pKa1) reveal a significant dependence upon conformation which may be rationalised in terms of hindrance to internal hydrogen bonding (‘hydrogen chelation’).
Patent•
17 Jul 1973TL;DR: New piperidine derivatives and esters and amides of substituted (piperidinyl-4) acetic acid are used as stabilisers for polymers, especially for polyolefines as mentioned in this paper.
Abstract: New piperidine derivatives and in particular esters and amides of substituted (piperidinyl-4) acetic acid are used as stabilisers for polymers, especially for polyolefines.
TL;DR: The results demonstrate the applicability of the shift reagent used with bifunctional systems containing two different heteroatoms and demonstrate a distorted chair form predominating in the conformational equilibrium of α- and β-tropines and tropinones.
Patent•
28 Dec 1973TL;DR: In this paper, the carboxylic acids are prepared from 2,2,6,6-tetramethyl-piperidin-4-ol and succinic acid.
Abstract: Compounds having the formula ##EQU1## wherein R 1 and R 2 are lower alkyl or cycloalkyl, R 3 is hydrogen, alkyl, methoxyethyl, alkenyl, propargyl, benzyl or alkyl substituted benzyl, R 4 is lower alkylene, M is a metal, and z has a value of from 1 to 4, And good light stabilizers. The carboxylic acids are prepared, for example, from 2,2,6,6-tetramethyl-piperidin-4-ol and succinic acid to give o-mono(2,2,6,6-tetramethyl-piperidin-4-ol)succinate. The metal salts of the acids are readily prepared by reacting the acids or their salts with a reactive form of the metal or metal complex.