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Showing papers on "Piperidine published in 2002"


Journal ArticleDOI
TL;DR: Test results show that a benzyl residue at the piperidine nitrogen atom and a methoxy group in position 3 are advantageous for high σ1-receptor affinity.
Abstract: A series of spiro[[2]benzopyran-1,4‘-piperidines] and spiro[[2]benzofuran-1,4‘-piperidines] of general structure 10 is prepared, and the affinity for σ1- and σ2-receptors is investigated by means of radioligand binding assays. The synthesis of the spiropiperidines 14a and 23 proceeds from bromine/lithium exchange of the bromoacetals 11 and 21, addition to piperidin-4-one 12a, and subsequent cyclization. Systematic variations of the substituent R at the nitrogen atom, the group X in position 3, and the ring size of the oxygen heterocycle are performed. The σ1- and σ2-receptor affinities are determined with guinea pig brain and rat liver membrane preparations using [3H]-labeled (+)-pentazocine and ditolylguanidine, respectively. Test results show that a benzyl residue at the piperidine nitrogen atom and a methoxy group in position 3 are advantageous for high σ1-receptor affinity. In this series the 1‘-benzyl-3-methoxy-3,4-dihydrospiro[[2]benzopyran-1,4‘-piperidine] (14a) and the 1‘-benzyl-3-methoxy-3H-spiro...

145 citations


Journal ArticleDOI
TL;DR: By performing the Fmoc resin loading determination with DBU instead of piperidine, highly reproducible results were obtained that showed excellent correlation with data obtained by independent analytical methods.
Abstract: By performing the Fmoc resin loading determination with DBU instead of piperidine, highly reproducible results were obtained that showed excellent correlation with data obtained by independent analytical methods.

122 citations


Journal ArticleDOI
TL;DR: Three-component condensation of 4-piperidinones, 5-pyrazolones, and malononitrile proceeds chemically and electrochemically and is a convenient one-step means of synthesis of substituted 6-amino-5-cyanospiro-4-(piperidine-4')-2H,4H-dihydropyrazolo[3,4-b]pyrans.

115 citations


Journal ArticleDOI
TL;DR: In this paper, the activation of S-phenyl 2,3-di-O-benzyl-alpha-D-thiomannopyranoside to a cross-linked polystyrene support in the form of its 4,6-Opolystyrylborinate ester is described.
Abstract: The linkage of S-phenyl 2,3-di-O-benzyl-alpha-D-thiomannopyranoside to a cross-linked polystyrene support in the form of its 4,6-O-polystyrylborinate ester is described. The activation of this polymer-supported mannosyl donor is achieved at -60 degrees C in dichloromethane in the presence of 2,4,6-tri-tert-butylpyrimidine with the combination 1-benzenesulfinyl piperidine and trifluoromethanesulfonic anhydride. Addition of the donor alcohol at -60 degrees C followed by warming to room temperature and subsequent cleavage from the resin by gentle heating in aqueous acetone yields anomerically pure 2,3-di-O-benzyl-beta-D-mannopyranosides in excellent yield. Successful, diastereoselective coupling is demonstrated with a range of primary, secondary, and tertiary glycosyl acceptors, including typical carbohydrates and threonine derivatives.

88 citations


Journal ArticleDOI
TL;DR: An enantioselective synthesis of the piperidine alkaloids (+)-sedamine and (-)-prosophylline is reported and the key steps are enantiOSElective allyltitanation reactions and ring-closing or cross-metathesis reactions.
Abstract: An enantioselective synthesis of the piperidine alkaloids (+)-sedamine and (-)-prosophylline is reported. The synthesis of (+)-sedamine has been achieved in 12 steps with an overall yield of 20% from benzaldehyde, and (-)-prosophylline was obtained in 15 steps with an overall yield of 9.2%, starting from D-glyceraldehyde acetonide 14. The key steps are enantioselective allyltitanation reactions and ring-closing or cross-metathesis reactions.

84 citations


Patent
28 May 2002
TL;DR: In this paper, a method to inhibit p38-α kinase using compounds comprising a phenyl or thienyl coupled through a piperidine or piperazine nucleus to an indole residue was proposed.
Abstract: The invention is directed to methods to inhibit p38-α kinase using compounds comprising a phenyl or thienyl coupled through a piperidine or piperazine nucleus to an indole residue wherein the indole residue mandatorily has a substituent on the ring nitrogen which is an amino or substituted amino group.

83 citations


Journal ArticleDOI
TL;DR: In this paper, a new efficient synthesis of 2-styryl-6,7-dichlorothiazolo[4,5-b] based fluorescent dyes was achieved by the condensation of 2methyl-6-7-DICD with selected 4-N,N-dialkylamino-linearaldehydes and hetero-dehydes in the presence of piperidine.

66 citations


Journal ArticleDOI
TL;DR: In this paper, a series of over 20 compounds based on pyrrole, indole, and carbazole chromophores were carried out in protic, nonpolar, and polar solvents.
Abstract: Photophysical studies of a series of over 20 compounds based on pyrrole, indole, and carbazole chromophores were carried out in protic, nonpolar, and polar solvents. Absorption spectra revealed the formation of ground-state hydrogen bonding with protic solvent partners. The equilibrium constants were determined by spectrophotometric titration. Strong fluorescence quenching was observed when azaaromatic proton acceptors, pyridine and quinoline, were used as protic solvents. No quenching occurs for nonaromatic protic partners such as dimethyl sulfoxide, morpholine, and piperidine, even though the ground-state equilibrium constants are not smaller. The rates of quenching in pyridine solutions at 293 K span a range from 1.2 × 109 to 5.9 × 1010 s-1 and are sensitive to minor structural variations. The mechanism of quenching involves an electron transfer from a photoexcited chromophore to a hydrogen-bonded partner, followed by a rapid internal conversion (back electron transfer) to the ground state. The quenchi...

64 citations


Journal ArticleDOI
TL;DR: Depending on the choice of amine, either cis- or trans-limonene oxide may be obtained in high diastereomeric purity by this simple and environmentally friendly method.
Abstract: cis- and trans-Diastereomers of (R)-(+)-limonene oxide can be purified by simple kinetic separation of the commercially available (1:1) diastereomeric mixture of limonene oxides. Nucleophilic amines, such as pyrrolidine and piperidine, selectively open the epoxide ring of the trans-isomer, leaving the cis-limonene oxide largely unreacted. The unreacted cis-(R)-limonene oxide is recovered in up to 88% yield. On the other hand, less nucleophilic amines, such as triazole or pyrazole, selectively catalyze hydrolysis of the cis-limonene oxide to 1,2-limonene diol leaving the trans-limonene oxide largely unreacted. The unreacted trans-limonene oxide is recovered in up to 80% of the theoretical yield by a simple workup procedure. The cis- and trans-diastereomers of (R)-(+)-limonene oxide thus isolated were found to be >98% pure by both GC and NMR analyses. Thus, depending on the choice of amine, either cis- or trans-limonene oxide may be obtained in high diastereomeric purity by this simple and environmentally friendly method.

62 citations


Journal ArticleDOI
TL;DR: The synthesis, chemical characterization, and interaction with cells of new sterically hindered trans- and cis-diaminedichloroplatinum(II) complexes are described, and cell death caused by both complexes appeared to be apoptotic according to several criteria including early phosphatidylserine exposure, activation of caspases, and characteristic morphological changes.
Abstract: The synthesis, chemical characterization, and interaction with cells of new sterically hindered trans- and cis-diaminedichloroplatinum(II) complexes are described. The amine ligands include monofunctional piperidine (pip) and piperazine (pz). The poor solubility of trans-diaminedichloroplatinum complexes was overcome by introducing the positively charged pz ligand, which allows retaining of the classic platinum coordination sphere. In vitro evaluation in OV-1063 and C-26 tumor cells revealed that replacing one NH3 of the inactive transplatin by an aromatic planar ligand (4-picoline, 4-pic) or by an aliphatic nonplanar heterocyclic ligand (pip) or replacing both NH3 groups with a 4-pic ligand and a pip or pz ligand significantly increases the cytotoxic activity of these complexes. The unsymmetric complexes trans-[PtCl2(4-pic)(pip)] and trans-[PtCl2(4-pic)(pz)]HCl were the most cytotoxic compounds against the cisplatin-sensitive tumor cell line C-26 (IC50 = 4.5 and 5.5 μM, respectively) and the cisplatin-se...

60 citations


Journal ArticleDOI
TL;DR: A small library of dendrimers based on triazines was prepared by varying the surface and interior linking groups to study the relationship between structure and the ability of some of these dendrilers to gel in acidified organic solvents including chloroform, methylene chloride, and benzene as mentioned in this paper.
Abstract: A small library of dendrimers based on triazines was prepared by varying the surface and interior linking groups to study the relationship between structure and the ability of some of these dendrimers to gel in acidified organic solvents including chloroform, methylene chloride, and benzene. Convergent, divergent, and semiconvergent routes yielded eight molecules comprising p-aminobenzylamine or piperazine linking groups and piperidine or butylamine surface groups. Dendrimers that incorporate interior and surface groups capable of hydrogen bonding (p-aminobenzylamine or butylamine) gel at lower concentrations than those groups that offer no hydrogen-bonding protons (piperazine or piperidine). In some cases, these latter molecules do not form gels to the limit of solubility. Studies with competitive solvents corroborate hydrogen bonding, but neither IR nor NMR spectroscopy reveals signals that substantiate this hypothesis. TEM studies show fibers. Studies of these systems at concentrations below that requi...

Journal ArticleDOI
TL;DR: C(2)-symmetric 2,6-diallylpiperidine 1-carboxylic acid methyl ester was examined via the double asymmetric allylboration of glutaraldehyde followed by aminocyclization and carbamation as a promising chiral building block for piperidine-related alkaloids.

Journal ArticleDOI
TL;DR: Diels-Alder reactions of enantiomerically enriched 2H-azirine 3-phosphonates and dienes stereoselectively furnish optically pure, bicyclic aziridine adducts that on hydrogenation afford the first examples of enantiopure quaternary piperidine phosphonates.

Journal ArticleDOI
TL;DR: Stereochemistry plays a major role in the selectivity toward zinc ion over copper(II) of some tripodal ligands with a central piperidine scaffold, one of which acts as a fluorescent zinc sensor with nanomolar sensitivity.

Journal ArticleDOI
TL;DR: An efficient synthesis of 3-substituted coumarins under solventless system is described in this article, where the synthesis of coumarin is performed using a solventless approach.
Abstract: An efficient synthesis of 3-substituted coumarins under solventless system is described.

Journal ArticleDOI
TL;DR: In this article, an X-ray crystallographic study located the bridging hydrogen in the anion on the open face between the two adjacent boron atoms, and compared with computed shifts at the GIAO B3LYP/6-311G* level.
Abstract: Deboronation of meta-carborane, closo-1,7-C2B10H12, with refluxing piperidine results in the quantitative formation of [(C5H10NH)2H+](nido-7,9-C2B9H12−) whose structure was determined by X-ray diffraction. Heating under vacuum liberates piperidine to give (C5H10NH2+)(nido-7,9-C2B9H12−). The reaction of meta-carborane with KOH in refluxing ethanol yields K+nido-7,9-C2B9H12− and the cage substituted anion 10-EtO-7,9-C2B9H11−. The protonated Proton Sponge salt (PSH+)(nido-7,9-C2B9H12−) (PS = 1,8-N,N,N′,N′-tetramethylnaphthalenediamine) was obtained by metathesis from the potassium salt, an X-ray crystallographic study located the bridging hydrogen in the anion on the open face between the two adjacent boron atoms. Anaerobic deboronation of para-carborane, closo-1,12-C2B10H12, with KOH in refluxing tetraglyme–toluene gives the potassium salt of nido-2,9-C2B9H12− from which 2,9-C2B9H13 was isolated in 45% yield by protonation. The salt (PSH+)(nido-2,9-C2B9H12−), obtained from nido-2,9-C2B9H13 and PS, was shown by single crystal X-ray crystallography to contain a hydrogen bridging two boron atoms opposite the carbon atom on the open face. Aerobic deboronation of para-carborane with KOH forms closo-1,10-C2B8H10 and 2-HO-closo-1,10-C2B8H9 in low yields. Fully assigned multinuclear NMR (11B, 13C and 1H) data are reported for the isomeric 7,8-, 7,9- and 2,9-nido-C2B9H12− anions and neutral 7,8- and 2,9-C2B9H13, and compared with computed shifts (at the GIAO B3LYP/6-311G* level) from optimized (at MP2/6-31G*) geometries.

Journal ArticleDOI
TL;DR: Cyclodehydration of achiral or racemic aryl-delta-oxoacids with (R)-phenylglycinol stereoselectively affords chiral non-racemic bicyclic lactams, from which the enantioselective synthesis of the piperidine alkaloid (-)-anabasine is reported.

Journal ArticleDOI
TL;DR: Indanol intermediates prepared via Michael addition of 1-indanone β-ketoester and acrylonitrile, followed by Grignard reaction of the ketone group, were submitted to an intramolecular Ritter reaction to produce cis-fused methyl 2-oxo-9b-phenyl-1,2,3,4,5,9b,hexahydro-4aH-indeno[1, 2-b]pyridine-carboxylates with 4a, 9b-diangular

Patent
11 Jan 2002
TL;DR: In this paper, a compound of formula (I) wherein R represents various substituent groups, is used as an inhibitor of glucosylceramide synthase and is shown to be useful as a deterministic inhibitor.
Abstract: Compounds of formula (I) wherein R represents various substituent groups, are useful as inhibitors of glucosylceramide synthase.

Journal ArticleDOI
TL;DR: In this article, a comparative analysis of 2-methylpyridine, 1-aminohexane, and 2-6-dimethylpiperidine was performed, and it was shown that pyridine ring opening occurs preferentially between the nitrogen atom and the methylene group.


Journal ArticleDOI
TL;DR: In this article, a multistep synthesis of anabasine analogues bearing a bioisosteric pyridazine moiety instead of a pyridine nucleus in 2-position of the piperidine ring of the alkaloid is described.

Journal ArticleDOI
TL;DR: Weinreb et al. as mentioned in this paper showed that (-)-epicylindrospermopsin (2) can be synthesized from 4-bromobenzyloxyacetaldehyde.
Abstract: A synthesis of (-)-epicylindrospermopsin (2) was completed that establishes its absolute configuration and corroborates the corrected structural assignment previously made to this toxin by Weinreb et al. The hydroxylamine 3, prepared from 4-bromobenzyloxyacetaldehyde, was condensed with aldehyde 4, obtained in nine steps from (R)-methionine, to give nitrone 16. Intramolecular cycloaddition of 16 proceeded stereoselectively to yield the oxazabicyclo[2.2.1]heptane 17, which after reduction and deprotection afforded piperidine 18. The latter was transformed via cyclic urea 19 to the inverted C12 alcohol 20, and the derived azide 22 was cyclized to produce the guanidine moiety of 25. Final sulfation of the C12 hydroxyl group furnished (-)-2.

Patent
24 May 2002
TL;DR: Piperidine derivatives and pharmaceutically acceptable derivatives thereof are useful in methods of treatment of bacterial infections in mammals, particularly man as mentioned in this paper, and they can be found in the literature.
Abstract: Piperidine derivatives and pharmaceutically acceptable derivatives thereof useful in methods of treatment of bacterial infections in mammals, particularly man.

Journal ArticleDOI
TL;DR: An asymmetric carbon-carbon bond-forming reaction at the 2-position of a p Piperidine skeleton was exploited to afford a 2-substituted piperidine skeleton with moderate enantioselectivity.

Journal ArticleDOI
01 Mar 2002-Synlett
TL;DR: In this paper, a Claisen-Eschenmoser type rearrangement giving rise to unsaturated morpholine-, piperidine-and pyrrolidine amides is described.
Abstract: A Claisen-Eschenmoser type rearrangement giving rise to unsaturated morpholine-, piperidine- and pyrrolidine amides is described.

Journal ArticleDOI
TL;DR: Tri-O-acetyl imino glucal 2 is readily made and shown to undergo a variety of Lewis acid mediated carbon-carbon bond forming reactions at C-1 of the piperidine nucleus.

Journal ArticleDOI
TL;DR: In this article, a stereoselective total synthesis of (+)-carpamic acid was achieved from the σ-symmetric 3-[dimethyl(phenyl)silyl]glutaric anhydride featuring its asymmetric desymmetrisation using oxazolidinone.

Journal ArticleDOI
TL;DR: The supramolecular structures have been determined for nine adducts formed between organic diamines and ferrocene-1,1'-dicarboxylic acid, and the hard hydrogen bonds generate three-dimensional structures.
Abstract: The supramolecular structures have been determined for nine adducts formed between organic diamines and ferrocene-1,1′-dicarboxylic acid. In the salt-like 1:1 adduct (1) formed with methylamine, the supramolecular structure is one-dimensional, whereas in the 1:1 adducts formed with 1,4-diazabi­cyclo[2.2.2]octane, (2), and 4,4′-bipyridyl, (4), and in the hydrated 2:1 adduct (3) formed with morpholine, the hard hydrogen bonds form one-dimensional structures, which are expanded to two dimensions by soft C—H⋯O hydrogen bonds. The hard hydrogen bonds generate two-dimensional structures in the 2:1 adduct (5) formed with octylamine, where the ferrocene component lies across a centre of inversion, in the 1:1 adduct (6) formed with piperidine and in the tetra­hydrofuran-solvated 1:1 adduct (7) formed with di(cyclo­hexyl)amine. In the 2:3 adduct (8) formed by tris-(2-aminoethyl)amine, and in the 2:1 adduct (9) formed with 2-(4′-hydroxyphenyl)ethylamine (tyramine), where Z′ = 1.5 in space group P\bar{1}, the hard hydrogen bonds generate three-dimensional structures. No H transfer from O to N occurs in (4) and only partial transfer of H occurs in (2); in (1), (6) and (7), one H is transferred to N from each acid molecule, and in (3), (5), (8) and (9), two H are transferred from each acid molecule.

Journal ArticleDOI
X. Eric Hu1
TL;DR: A piperidinyl aziridine underwent alcoholic nucleophilic addition with alcohols to result in corresponding trans 3-amino-4-substituted piperidine as discussed by the authors.