Showing papers on "Piperidine published in 1974"

Piperidine Increase in the Brain of Dormant Mice

Abstract: During a 2-hour period of dormancy (sleep), piperidine is accumulated in the mouse brain.

Derivatives of pyrrolidine and piperidine

Abstract: Certain compounds in which a carbon atom of a pyrrolidine or piperidine ring is bonded directly or through a methylene group to the nitrogen of a substituted benzamido group, and their pharmaceutically acceptable salts, are found to be active as antiarrhythmic agents.

Über Anilinomethylenverbindungen der Cyclohexandione

Abstract: 1.3-Cyclohexanediones easily react with aromatic amines and triethyl orthoformate yielding enaminoketones. With malononitrile and KOH hexahydroquinolinediones can be obtained, in the presence of piperidine cyclisation to hexahydroisoquinolinones occurs. The way of cyclisation depends upon the amine part of the used enaminoketones.

4-Aminoquinoline derivatives

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) -NR1 N-R3 (IIIa) OR -N N NR1R2 (IIIb) 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-hypertensive activity and, in some cases, show one or more of the following activities: anti-malarial activity, anti-inflammatory activity, anti-trichomonal activity and inhibition of blood platelet aggregation.

Estimation of picomole quantities of piperidine in tissues

Abstract: Piperidine is a putative neurotransmitter. Its sensitive determination is one of the prerequisites for the evaluation of its assumed physiological role. For its derivatization 5-di-n-butylaminonaphthalene-1-sulphonyl chloride, a new reagent which improves methods applying 5-dimethylaminonaphthalene-1-sulphonyl chloride, is used. Reaction of the perchloric acid tissue extract with this reagent, thin-layer chromatographic separation of the fluorescent derivatives and mass spectrometric evaluation of the di-n-butylaminonaphthalenesulphonyl piperidine spot by a version of the integrated ion current technique allows the determination of piperidine in tissues in picomole quantities. Standard deviation of the determinations of 2 to 16 pmol of piperidine added to 50 mg of brain tissue was ±8%. The method was applied to the analysis of different tissues. Brain concentrations of piperidine in different species were found to be lower by a factor up to 100 in comparison with published data.

Conformational analysis of the tropane analogue of pethidine and related compounds by 1H NMR spectroscopy

Abstract: The preferred solute conformation of ethyl 3α-phenyltropane-3β-carboxylate hydrochloride, the tropane analogue of pethidine, is shown to be a piperidine chair with an axial 3-phenyl substituent by analysis of its 1H NMR characteristics and spectral comparisons with model compounds. Conformational studies of synthetic intermediates are also reported and favoured boat forms identified for 3α-diphenylhydroxymethyl-3β-tropanol and 3α-phenyl-3β-tropanyl phenyl ketone. In the hot-plate test for analgesia performed on mice, ethyl 3α-phenyltropane-3β-carboxylate is about 1·5 times as effective as pethidine.

Reaction of amines with 1,3-dienes catalysed by nickel complexes

Abstract: Reactions of morpholine, piperidine, pyrrolidine, di-n-propylamine, n-butylamine, aniline, and p-anisidine with buta-1,3-diene in the presence of catalytic quantities of nickel acetylacetonate and di-isopropoxyphenylphosphine have been studied. Mixtures of 1 : 1 (butenyl) and 2 : 1 (octadienyl) amine products are produced and the reaction with morpholine has been studied in detail to examine the factors determining the product mixtures. Butenyl adduct formation is favoured by (a) a 3 : 1 ratio of phosphine–nickel salt concentration, (b) use of nickel halides with ethanol solvent, and (c) a low effective concentration of butadiene. A product mixture containing 86% octadienyl adduct was obtained by using a preformed Ni0 complex Ni[P(OPh)3]4. Reaction of morpholine and isoprene gave mainly a 1 : 1 adduct and small amounts of a 2 : 1 adduct; a similar reaction with trans-piperylene gave only a 1 : 1 adduct. The mechanism of the reactions is discussed in terms of formation of the butenyl and octadienyl adduct formation from π-allylnickel and bis-π-allylnickel complexes. The use of cocatalysts such as sodium borohydride in the reactions is discussed. Isomerisation of branched to linear butenyl adduct has been demonstrated to occur.

New Synthesis of Nitroxyl Radicals of the Piperidine and Tetrahydropyridine Series

Abstract: 1-Oxyl-2,2,6,6-tetramethyl-4-piperidone cyanohydrin (5) was prepared by addition of HCN to 1-oxyl-2,2,6,6-tetramethyl-4-piperidone (4). The cyanohydrin was used to synthesize 1-oxyl-4-carboxy-2,2,6,6-tetramethylpiperidine (2) and 1-oxyl-4-carboxy-2,2,6,6-tetramethyl-1,2,5,6-tetrahydropyridine (3) which are useful nitroxyl radicals for spin labeling studies.

Aspects of catalysis. Part III. Soluble iridium-containing catalysts for the reduction of cyclohexanones by propan-2-ol and for the formation of ethers from cyclohexanones (or enol ethers) and alcohols

Abstract: Transfer of hydrogen from propan-2-ol (containing water) to relatively unhindered cyclohexanones is catalysed by some soluble iridium compounds. Stereoselectivity in the reduction of a substituted cyclohexanon depends on the ligands associated with the iridium. The proportion of axial alcohol from the reduction of cholestan-3-one or 4-t-butylcyclohexanone ranges from 30–23%(piperidine present) to 66–78%(dimethyl sulphoxide present). Preformed iridium–sulphoxide complexes also give the latter degree of stereoselectivity. In the absence of water these complexes catalyse another reaction between cyclohexanones and alcohols, ethers being formed by reductive etherification of the ketones. The reaction favours the production of axial ethers and higher yields of ether can be obtained by starting with the ketone in the form of an enol ether.

Preparation, Infrared Spectra, Electronic Spectra, and Magnetic Moments of Copper(II) Complexes of N-Acetylglycine and Their Amine Adducts

Abstract: Compounds of the type [CuA2•H2O]2 and [CuA2•4H2O]2 have been prepared, where A is N-acetylglycine (aceturic acid). Amine adducts of the type CuA2B (B = piperazine, 2,2′-bipyridine, and 1,10-phenantroline) and CuA2B2 (B = N-methylpiperazine, piperidine, morpholine, pyridine, and ethylenediamine) were obtained by reaction of the amines with CuA2•4H2O. Each complex was characterized by elemental analysis, infrared spectrum, electronic spectrum, and magnetic moment. For the piperazine and ethylenediamine adducts a square-planar pattern of coordination about copper(II) ion is probable, while for the other amine adducts a square-pyramidal structure is proposed. For all the complexes the coordination of the N-acetylglycine occurs only through the terminal carboxyl oxygen in a monodentate arrangement.

Reaction of butadiene with Schiff bases catalysed by a palladium complex. Formation of a derivative of piperidine

Abstract: Reaction of butadiene with Schiff bases is catalysed by Pd(NO3)2–Ph3P to give 2,3,6-trisubstituted piperidines.

Stabilized synthetic polymer compositions

Abstract: A synthetic polymer composition stabilized against photo- and thermal-deterioration thereof wherein there is incorporated, in a sufficient amount to prevent such deterioration, 1-substituted piperidine derivatives.

Conformational equilibrium in N-methylpiperidine

Abstract: Kinetically controlled protonation of piperidines has been developed into a reliable method for studying conformational equilibria in piperidine and its alkyl derivatives; in N-methylpiperidine (1) the equatorial coniormer 1E is more stable than the axial 1A by 11.3 ± 0.8 kJ mol–1 in cyclohexane and by <12·5 kJ mol–1 in the gas phase, at 288 K.

Diversity in the course of the reactions of the 4‐halogenoisoquinolines with potassium amide in liquid ammonia and with piperidine

Abstract: The reactions of the 4-X-isoquinolines (X=F, Cl, Br, I) with potassium amide in liquid ammonia were investigated. In amounts depending on the halogen present, 1-amino-4-X-isoquinoline and 1-aminoisoquinoline are formed by a Chichibabin-type reaction and an abnormal AE mechanism, respectively. Evidence for the intermediate tetrahedral complex in position 1 was obtained by PMR measurements on 4-chloroisoquinoline. In the case of 4-bromo- and 4-iodoisoquinolines reduction and coupling processes occur at the same time, leading to isoquinoline, 4,4′-biisoquinoline and 1-amino-4,4′-biisoquinoline, probably via a carbanion initially formed. Abnormal substitution was also established together with the normal AE process in the reactions of 4-chloro-, 4-bromo- and 4-iodo-isoquinolines with piperidine, yielding both 1-piperidinoisoquinoline and 4-piperidino-isoquinoline.

Acetato‐ and Propionato‐(Saturated Heterocyclic) Amine Complexes of Cobalt(II), Nickel(II), and Copper(II)

Abstract: Die bis-Acetato- und Propionato-Metalladdukte von Piperidin-(pipd), Piperazin(pipz), N-Methylpiperazin(CH3-pipz) und Morpholin(morph) wurden in festem Zustande isoliert und optisch und magnetisch untersucht. Piperazin bildet 1:1-Komplexe, die anderen Amine bilden 1:2-Komplexe. Die IR-Spektren ergeben, das die Amine an das Metallatom uber das N-Atom koordiniert sind, Acetat und Propionat sind symmetrische oder asymmetrische zweizahnige Liganden. In Monopiperazin-Addukten verbruckt das Amin zwei Metallatome. Elektronenspektren und magnetische Momente weisen auf eine transoktaedrische Konfiguration der Addukte. Acetato- und Propionato-Komplexe gesattigter N-Heterozyclen mit CoII, NiII und CuII The bis acetato and propionatometal-adducts of piperidine (pipd), piperazine (pipz), N-methylpiperazine (CH3-pipz) and morpholine (morph) are isolated in the solid state and investigated by spectral and magnetic measurements. Piperazine forms 1:1 complexes, the other amines 1:2 complexes. The infrared spectra show that the amines are coordinated to the metal atom toward the nitrogen atom and that the acetate and propionate act as symmetrical or asymmetrical bidentate ligands. The i.r. spectra give also evidence that in monopiperazine adducts the amine “bridges” two metal atoms. Electronic spectra and magnetic moments suggest a tran-octahedral configuration of the adducts.

Steric Effects in the Nitrosation of Piperidines

Abstract: Summary The rates of reaction with nitrous acid of four methylsubstituted piperidines to form the corresponding N -nitrosopiperidines were compared with that of piperidine. The relative rates for piperidine, 2-methyl-, 2,6-dimethyl-, and 2,2,6,6-tetramethyl-piperidine were approximately 100:20:10:1, showing considerable steric hindrance to nitrosation by the α methyl groups. The rate of formation of nitrosopiperidine from the tertiary amine N -methylpiperidine was about 10,000 times slower than that from piperidine.

4-Acetyl-2,3-dimethyl-6-isopropenylmethyl-cyclohexene

Abstract: AND (III) AND A MIXTURE OF COMPOUNDS HAVING THE II. A mixture of compounds having the structure: A superatmospheric process for directly producing a Diels-Alder adduct which comprises admixing: I. A conjugated diene which can be either alpha-terpinene, alloocimene, cyclopentadiene or myrcene; with II. A carbonyl group-containing compound which can be either acetone, acetaldehyde propionaldehyde or methylethyl ketone; with III. An aldehyde source which can be either a formaldehyde source or an acetaldehyde source which aldehyde source will yield formaldehyde or acetaldehyde; in the presence of IV. A secondary amine catalyst such as a lower dialkyl amine or a cyclic amine such as morpholine, pyrrolidine or piperidine, AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 120*C up to about 200*C for a period of time from about 2 hours up to about 8 hours, and novel products produced therefrom to wit: I. A mixture of compounds having the structures:

1-(Naphthylalkyl- or indenylalkyl)-piperidines

Abstract: A group of heterocyclic compounds useful in the treatment of disorders and diseases of the cardiovascular system and/or in the treatment of superficial deep allergic phenomena is described. These are piperidine compounds linked by naphthyl, 1,2,3,4-tetrahydronaphthyl or idenyl radicals through the intermediary of a group selected from a lower-alkylene radical, a mono- -keto lower-alkylene radical or a hydroxy-lower-alkylene radical, or a bivalent radical of the formula OH ¦ -O-CH2.CH.CH2- or -O(lower-alkylene)-. The ring is further substituted by an amino or acylamino residue.

Heterocyclic syntheses. Part XXVIII. ortho-Dialkylamino-benzenesulphonyl azides, -benzoyl azides, and -benzoyldiazomethanes

Abstract: A series of the title compounds incorporating ortho-dimethylamino, diethylamino, dipropylamino, pyrrolidin-1-yl, piperidino, morpholino, 4-methylpiperazin-1-yl, perhydroazepin-1-yl, perhydroazocin-1-yl, and perhydroazonin-1-yl groups were prepared. Thermal decomposition of the sulphonyl azides in solution in chlorobenzene or dimethyl sulphoxide resulted in attack on the ortho-nitrogen atom to give mesoionic spirobenzothiadiazoles or (by ring-opening or dealkylation) 3-substituted benzothiadiazoles. The pyrrolidinyl system was unique in giving a variety of products derived by Curtius rearrangement or otherwise from an intermediate sulphonylnitrene. Thermolysis in the presence of a catalytic amount of base hydrochloride, or an excess of piperidine or of copper, gave a dihydrobenzothiadiazine by attack on an N-methylene group. Photolysis of the sulphonyl azides in solution in dimethyl sulphoxide gave the benzothiadiazines, but by a mechanism different from that of the thermal reaction which did not involve oxidation by dimethyl sulphoxide. The carbonyl azides spontaneously decomposed to give conventional products of a Curtius rearrangement, and one diazo-ketone gave a mesoionic system analogous to those derived from the sulphonyl azides. Unusual properties are associated with some of the intermediates prepared, and are accounted for by a neighbouring group effect. Mechanisms are proposed for the observed reaction pathways.

Electron spin resonance studies. Part XLI. Investigations of structure and conformation. Part III. Conformational interconversion in some heterocyclic radicals

Abstract: Radicals have been generated in aqueous solution from pyrrolidine, morpholine, 1,4-dioxan, piperidine, and some alkyl-substituted derivatives, by reaction with ·OH at low pH. Analysis of e.s.r. hyperfine splittings and line-widths recorded over the attainable temperature range (ca. 5–45°) yields kinetic and thermodynamic information about conformational interconversion in these species. The five-membered-ring radicals undergo rapid interconversion between half-chair geometries; the conformational preference for a methyl group in this system is 1·4 kJ mol–1 at 23°. In contrast, the radical from piperidine undergoes chair–chair ring-flipping with rate constants in the range intermediate between fast and slow exchange [e.g.(2·5 ± 0·2)× 109 s–1 at 39°]; activation parameters for this interconversion are Ea= 30·4 ± 3·0 kJ mol–1 and log10A= 14·5 ± 0·2.

Process for the preparation of hydroxylamines by hydrogenation of aromatic nitro derivatives

Abstract: Aromatic hydroxylamines are prepared by hydrogenating the corresponding aromatic nitro compound in the presence of a platinum catalyst and organic base which is a secondary or tertiary alkyl or cycloalkyl monoamine, pyrrolidine or piperidine or N- or C- alkyl derivatives thereof, N-alkyl or N-cycloalkyl anilines or C-alkyl derivatives thereof, pyridine, alkylpyridines, quinoline or isoquinoline, the weight ratio of organic base to nitro compound being greater than 0.1:1.

Steric effects in nucleophilic substitution of five-membered rings. Influence of the nature of the leaving group on secondary steric effects

Abstract: Kinetic data from the substitution of piperidine into some 2-substituted 3,5-dinitro-4-methyl-(IIa–d) and 3,5-dinitro-thiophens (Ia–d) show the occurrence of a small secondary steric effect (k(Id)/k(IId)= 8) only when the leaving group is SO2Ph. This effect seems to depend on the interaction of the groups at C-2, –3, and –4 of the thiophen ring, as the results obtained for other thiophens indicate.

Triazines and related products. Part XIII. Decomposition of 4-Arylamino-1,2,3-benzotriazines and their precursors in secondary amines

Abstract: 4-Arylamino-1,2,3-benzotriazines (1) decompose in piperidine and related secondary amines to afford NNN′-trisubstituted 2-aminobenzamidines (4) in excellent yields. 4-o-Aminoanilinobenzotriazine (1f) yields 2-(2-aminophenyl)benzimidazole (9) when heated in ethylene glycol or piperidine. Nucleophilic attack by the amines at C-4 of the triazine ring is implicated in these transformations. 1-o-Cyanophenyl-3-m-cyanophenyltriazene (13a) is unreactive in piperidine whereas the p-cyanophenyltriazene isomer (13b) yields 2-amino-N′-p-cyanophenyl-NN-pentamethylenebenzamidine (4b). 1,3-Bis-o-cyanophenyltriazene (13c) rearranges and decomposes in boiling piperidine, pyrrolidine, morpholine, diethylamine, di-n-propylamine, and piperazine to afford the triazenylquinazolines (19)–(24), respectively.