Showing papers on "Piperidine published in 1979"

The chemistry of nitroso-compounds. Part 11. Nitrosation of amines by the two-phase interaction of amines in solution with gaseous oxides of nitrogen

Abstract: The formation of secondary N-nitrosoamines when MeCN solutions of amines are brought into contact with gaseous NO, N2O3, and N2O4 at 25 °C is reported. With NO, N-nitrosoamine formation from piperidine, morpholine, and diphenylamine occurs very slowly (t½ca. 8 days). Reaction rates are largely independent of the amine, suggesting that oxidation of NO by adventitious oxygen is the slow step. Very much faster reactions are observed, however, with N2O3 and N2O4. With a ca. 10-fold excess of N2O3 or N2O4, quantitative yields of both N-nitrosopiperidine and N-nitrosodiphenylamine are found in less than 3 min. With a 27-fold excess of piperidine and N2O4 only, ca. 8%N-nitropiperidine and 92%N-nitrosopiperidine are obtained. Rapid reactions also ensue when solutions of either primary aromatic or secondary amines dissolved in 0.1M-aqueous NaOH are brought into contact with gaseous N2O3 and N2O4. With a ca. 2–400-fold excess of these nitrogen oxides, 12–65% of the amine is converted either to N-nitrosoamine or diazonium ion in less than 3 min. Competitive hydrolysis of the nitrogen oxide by the solvent is not HO–-catalysed and the amine : H2O reactivities are in ca. 1 000 : 1. The extent of N-nitrosation varies insignificantly over a wide range of basicities (pKa, 11.12 to –1.0), but no reaction occurs with either 2,4-dinitroaniline or N-butyl-acetamide. With N2O4, smaller amounts of N-nitroamines form concurrently and increase with decreasing amine basicity. The results are discussed in relation to amine nitrosation by N2O3 and N2O4 in aqueous acidic solutions. It is suggested that the lower selectivity for the dissolved gaseous reagents may relate to the presence of more reactive N2O3 and N2O4 isomers. The results also show that carcinogenic N-nitrosoamines form under a much wider range of experimental conditions than previously known, some of which are relevant to atmospheric pollution.

Piperidine containing malonic acid derivatives

Abstract: Malonic acid derivatives of the formula ##STR1## wherein Z contain sterically hindered piperidines as stabilizers against light-induced degradation for organic material.

Pyridopyrazine and quinoxaline derivatives, processes for their preparation, and pharmaceutical compositions containing them

Abstract: There are described compounds of formula I, in which R1 is phenyl substituted by halogen, alkoxy, alkyl, carboxy-alkyl, -NR4R5, carboxy or alkoxy carbonyl, R3 is hydrogen, alkyl, mono- or di-carboxy alkyl, halo, alkoxy, phenyl, halo-phenyl, hydroxy, phenoxy, thiol, thioalkoxy, thiophenoxy, -NR4Rs, cyano, -COOH, carboxyureido, -CF3, -CORe, hydroxyalkyl, aminoalkyl, or alkoxy substituted by NR4R5, ring A is a benzene or a pyridine ring which optionally carries up to 4 substituents R3, which may be the same or different, R4 and Rs, which may be the same or different, each represent hydrogen, phenyl, halophenyl or alkyl, the alkyl optionally being substituted by alkoxy or by a mono- or di- alkyl or unsubstituted amino group; or R4 and Rs, together with the nitrogen atom to which they are attached, form a piperidine, morpholine or an optionally alkyl substitued piperazine ring, and R6 is hydrogen or alkyl, provided that (i) when R, is phenyl substituted by chlorine or bromine, ring A is not a benzene ring substituted by chlorine or bromine, or (ii) when R, is phenyl substituted by methoxy R3 is not phenyl, and pharmaceutically acceptable salts, esters and amides thereof. There are also described methods for making the compounds and pharmaceutical, e.g. anti-inflammatory, compositions containing the compounds.

Hypotensive piperidine derivatives

Abstract: The present invention relates to a novel compound represented by the general formula: ##STR1## wherein Ar represents a naphthyl, phenyl or substituted phenyl group, Q represents ##STR2## wherein R 1 represents a hydrogen atom, or an alkyl, alkanoyl or alkoxycarbonyl group, R represents a hydrogen atom or an alkyl group, and Z represents a substituted benzimidazolinyl group; the broken line in piperidine ring means that 3,4-positions in the piperidine ring are saturated or form a double bond. Said compound and the pharmaceutically acceptable acid addition salts thereof have a hypotensive action and therefore are useful as medicine.

Biosynthesis of slaframine, (1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine, a parasympathomimetic alkaloid of fungal origin. 3. Origin of the pyrrolidine ring.

Abstract: The phytopathogen Rhizoctonia leguminicola has previously been shown to incorporate pipecolic acid into the piperidine alkaloids 1-acetoxy-6-aminooctahydroindolizine (slaframine) and 3,4,5-trihydroxyoctahydro-1-pyrindine. In the experiments described here, resting cultures of R. leguminicola were incubated with [1-14C]- and [2-14C]malonic acid and with [1-14C]- and [2-2H]acetic acid. Both acids were incorporated into the ring systems of both alkaloids. Mass spectrometric analysis of 2H-enriched slaframine showed that the label resides in the five-membered ring and that the methyl carbon of acetate is joined to the carboxyl carbon of pipecolate. A pipecolate-dependent decarboxylation of [1-14C]malonate was demonstrated in cell-free extracts of R. leguminicola. The results account for previously unattributed carbons in the two alkaloids and suggest the formation of an eight-carbon intermediate common to both alkaloids by acylation of malonate with pipecolic acid.

Metabolites of loperamide in rats.

Abstract: Following intraperitoneal administration to rats of [14C]loperamide, [carbonyl-14] 4-(p-chlorophenyl)-4-hydroxy-N,N-dimethyl-alpha, alpha-diphenyl-1-piperidine butyramide, metabolites in feces and urine were separated, and identified by means of mass spectrometry. In feces, six metabolites were identified in addition to the unchanged drug. The main metabolic pathways involved are dealkylation in the dimethyl amide moiety to give desmethyl- and didesmethylloperamide, both of which were in turn monohydroxylated either in the alpha-phenyl ring or possibly in the alpha-carbon in the piperidine ring. It is noteworthy that metabolites hydroxylated in the piperidine ring were isolated as pyridinium derivatives, possibly due to spontaneous aromatization of its 2,4-dihydroxy-4-(p-chlorophenyl)piperidine ring. In urine, only two metabolites were found and identified to be desmethyl- and didesmethylloperamide, since [14C]loperamide was excreted into urine only in a small amount.

Polyalkylpiperidine derivatives of s-triazines, their use as stabilizers for polymers and polymers thus stabilized

Abstract: Polyalkyipiperidinderivate which are unsubstituted in the 1-position of the piperidine ring and are bonded in the 4-position via a heteroatom-bridge on a s-triazine may be prepared by reaction with a dihalide or a di-, tri- or tetraepoxide in compounds of formula I convert, wherein m is 2, 3 or. 4 Assuming a triazine derivative which has at least two Polyalkyipiperidin-Subsdtuenten, is obtained in the reaction with polymeric dihalides or diepoxides or oligomeric compounds of the formula II, wherein n is the degree of polymerization and E and E 'represent the end groups. Both types of compounds are stabilizers for polymers, especially against damage by light. They are characterized by low volatility and low migration tendency aodas them especially for use in thin polymer layers, such as in fibers, films or coatings of Intereese.

Addition of nitrogen-, oxygen-, and sulphur-containing nucleophiles to aryl ethynyl ketones

Abstract: Addition of some nitrogen-, oxygen-, and sulphur-containing nucleophiles to the aryl ethynyl ketones (1)–(4) has been examined. Addition of o-phenylenediamine and o-aminophenol yielded the corresponding cis-β-aminovinyl ketones (5)–(7) and (10)–(12). Addition of secondary amines (morpholine and piperidine) yielded the trans-β-aminovinyl ketones (13)–(20). Catechol reacted with aryl ethynyl ketones to furnish 1,3-benzodioxole derivatives (21)–(23), salicylic acid and 2-hydroxy-3-naphthoic acid to give the oxalactones (24)–(30). However, 2-hydroxy-1-naphthoic acid yielded a mixture of the oxalactones (31)–(33) and 3-naphthoxy-1-arylprop-2-enones (35) and (36). Similarly thiosalicylic acid gave the corresponding thialactones (40) and (41) as addition products. Salicylaldehyde reacted with ethynyl phenyl ketone to give 3-benzoylchrom-3-en-2-ol (38).

Effect of hindered piperidine derivatives on polypropylene photooxidation

Abstract: The photostabilizing effect of a hindered piperidine derivative was studied in the photooxidation of polypropylene films by following the formation of carbonyl and hydroperoxide groups, as well as the change of concentration of the stabilizer. This additive — the tetramethylpiperidine sebacate — proved to be more effective than hydroxybenzophenone, hydroxybenztriazole or a sulphur containing nickel complex, since no oxidation products were formed after irradiation with 20O Mlxh dose.

Hypobetalipoproteinemic agents. 2. Compounds related to 4-(1-adamantyloxy)aniline.

Abstract: While the previously used displacement reaction of sodim 1-adamantyl oxide on 4-fluoronitrobenzene was applicable to the preparation of 4-(1-adamantyloxy)aniline and several related compounds, certain derivatives were not easily accessible by this route. Thus the recently reported ortho alkylation of anilines and the dicyclohexylcarbodiimide-promoted coupling of 1-adamantanol with phenols were useful in the preparation of aromatic-substituted derivatives. Furthermore, addition of phenylmagnesium bromide to 1-cyanoadamantane provided entry to the 4-(1-adamantylmethyl)aniline series. 4-(1-Adamantyloxy)aniline (3) is herein reported to be a more potent hypobetalipoproteinemic agent than the previously reported bicyclooctyloxy analogue. Replacement of the oxygen atom of 3 with sulfur (74) or methylene (62), but not nitrogen (71), results in active compounds. In the oxygen series derived from 3, the widest scope of substitution on nitrogen resulting in activity is found. The N-ethoxycarbonyl (5), acetyl (6), methyl (12), ethyl (13), N-methyl-N-(2-hydroxyethyl) (19), N-methyl-N-formyl (22), N,N-dimethyl (26), pyrrolidine (14), and piperidine (15) derivatives are active. Aromatic ring substitution also provided the active 3-chloro (44b), 2-fluoro (41b, 42, and 43), and 2-methylthiomethyl (48) compounds. Thus these active compounds are identified for further development as hypobetalipoproteinemic agents.

Tetra-alkyl piperidine derivatives as light stabilizers

Abstract: Compounds which contain, in their molecule, at least one 2-(2'-hydroxyphenyl)-benztriazole group or one 2-hydroxybenzophenone group and at least one polyalkylpiperidine group are effective light stabilizers for organic materials, in particular for polymers. The use of the compounds as light stabilizers for lacquers is of particular importance.

The chemistry of nitroso-compounds. Part 15. Formation of N-nitrosamines in solution from gaseous nitric oxide in the presence of iodine

Abstract: Quantitative results are reported for the N-nitrosation of piperidine, morpholine, and N-methylpiperazine by NO (saturated) and iodine under anaerobic conditions in solvent EtOH, EtOH–water, and MeCN at 25 °C. The reactions are very much faster than those with NO in the absence of iodine, with maximum yields of N-nitrosamine being obtained in ca. 5–30 min depending on the solvent. The rates, however, are largely independent of the initial concentrations of either amine or iodine, and are similar for all three amines despite their different basicities. With excess of amine, 2 moles of N-nitrosamine are obtained per mole of iodine. Otherwise, the limiting yields of N-nitrosamine depend on both the concentration and basicity of the amine, with ca. 50, 66, and 100% reacting for piperidine, morpholine, and N-methylpiperazine, respectively. Addition of NaOH to the reaction solution, however, increases the yield to 100% throughout. Both added NaN3 and thiourea inhibit the formation of N-nitrosamines. The mechanism of these reactions is considered to involve rate-limiting formation of NOI (principally from NO and I2) followed by rapid reaction with the amine base. The amine cation is unreactive; NaN3 and thiourea inhibit reaction by competing for the NOI reagent. The results are also discussed in relation to human exposure to carcinogenic N-nitrosamines.

A process for the preparation of ferrierite, ferrierite thus obtained and its use as catalyst or catalyst carrier for converting hydrocarbons, and for separating hydrocarbons

Abstract: A process for the preparation of ferrierite by heating at a temperature between 100 and 200° C an aqueous mixture which contains a compound of an alkali metal (M), a compound of aluminium, a compound of silicon, and piperidine and/or alkylsubstituted piperidine (NR), in which aqueous mixture the various compounds are present in the following molar ratios, which except for piperidine and alkyl-substituted piperidine, are expressed in moles of the oxides: and Ferrierite thus obtained and its use as catalyst or catalyst carrier for converting hydrocarbons and as molecular sieve, for instance for separating hydrocarbons.

Bis(N-acetyl-DL-leucinate)copper(II) complexes and their amine adducts.

Abstract: A compound of the type Cu(AcLeu)2 and its amine adducts of the type Cu(AcLeu)2Bn (AcLeu=N-acetyl-DL-leucinato ion; n=2 and B=pyridine, 3- and 4-methylpyridine, N-methylpiperazine, morpholine, and piperidine; n=1 and B=1,10-phenanthroline, 2,2′-bipyridyl, piperazine, and pyridazine) were prepared and investigated by means of electronic, infrared and EPR spectroscopy and magnetic moment measurements. The results suggest a tetragonal configuration for the Cu(AcLeu)2 complex and the amine adducts with CuO4 and CuO2N2 chromophores, respectively. For the green Cu(AcLeu)2·pid complex a binuclear configuration similar to that observed for the bis(acetato)copper(II) monohydrate complex is suggested. The amino acid in all the complexes is found to coordinate toward the carboxylato group. In the assignment of the way in which the carboxylato group coordinates, in addition to the difference between their antisymmetric and symmetric stretching frequencies, we also pay special attention to the position of the symmetric...

Neuroleptic-4-(naphthylmethyl)piperidine derivatives

Abstract: Novel compounds of the formula ##STR1## wherein n is an integer of from 2 to 5, R is hydrogen, alkyl, alkoxy, halogen or trifluoromethyl, R 1 is hydrogen, alkyl, alkoxy or halogen, X is carbonyl, hydroxymethylene or methylene, and Z is carbonyl or hydroxymethylene and their pharmaceutically acceptable acid addition salts are useful as antipsychotic agents having a low potential for extrapyramidal side effects. The novel compounds are prepared from novel intermediates of formula ##STR2## or their salts wherein R and X have the meanings defined above.

Piperidine compounds and their use as stabilizers for synthetic polymers

Abstract: New piperidine compounds of the formula ##STR1## in which the radicals have the meanings indicated in the specification and which are stabilizers against light, heat and oxidation for synthetic polymers.

Cyansäureester, 27 [1]. Triazino-benzimidazole aus 2-Amino-benzimidazol-1-imidsäureestern und carbonylanalogen Verbindungen†

Abstract: Cyanic Acid Esters. 27. Triazino-benzimidazoles from 2-Amino-benzimidazole-1-imid-esters and Carbonyl Analogic Compounds The Cyclocondensation of 2-amino-benzimidazole-1-imid-esters with aldehydes, carbonic acid anhydrides and isocyanates has been investigated. With aldehydes in the presence of piperidine 4-aryloxy-1,2-dihydro-1,3,5-triazino[1,2-a]benzimidazoles 3 and with carbonic acid anhydrides 4-aryloxy-1,3,5-triazino[1,2-a]benzimidazoles 5 are formed. Isocyanates react with the imid esters to the corresponding 3-substituted ureas 8 which on heating undergo acyl migration of the carbamoyl group followed by cyclocondensation to 4-imino-2-oxo-1,2,3,4-tetrahydro-1,3,5-triazino[1,2-a]benzimidazoles 12.

Studies on psychotropic agents. V. Synthesis of 1-substituted spiro[dibenz[b,f]oxepin-11,4'-piperidine]-10(11H)-one and related compounds.

Abstract: Ausgehend von den tricy- clischen Ketonen (I) werden die Carbamidsaureester (V) dargestellt, von denen nur (Va) epoxidiert werden kann.

Catalysis in aromatic nucleophilic substitution. Part 4. Reactions of piperidine with 2-methoxy-3-nitrothiophen in benzene

Abstract: The rate of piperidino-substitution of 2-methoxy-3-nitrothiophen (I) in benzene as a function of amine concentration has been studied. The reaction is strongly catalysed by piperidine, being third-order overall (second-order in amine) and represents the first example of an SNAr of an ortho- or ortho-like mononitro-substituted derivative for which base catalysis is needed in benzene. The results obtained have been interpreted by taking into account the properties of the leaving group and its peculiar ortho-like relation with the activating nitro group.