Search results for "tertiary amine"
showing 10 items of 46 documents
Structure-activity relationships of dimethindene derivatives as new M2-selective muscarinic receptor antagonists.
2003
A series of 2,3-disubstituted indenes, which are analogues of the widely used histamine H(1) receptor antagonist dimethindene, have been synthesized and studied as muscarinic and histamine receptor antagonists. The affinities of these compounds for the five human muscarinic receptor subtypes (M(1)-M(5)) and for human histamine H(1) receptors were determined in radioligand binding studies using membranes from transfected Chinese hamster ovary (CHO) cells and [(3)H]N-methylscopolamine ([(3)H]NMS). The results demonstrate that the diisopropyl analogue 19 has a similar high affinity as (S)-dimethindene at M(2) receptors ((S)-dimethindene: pK(i) = 7.52; (-)-19: pK(i) = 7.37) with an improved sel…
Aldol Reactions with Erythrulose Derivatives: Stereoselective Synthesis of Differentially Protected syn -α,β-Dihydroxy Esters
2000
Boron enolates of 1-O-silylated erythrulose 3,4-acetonides prepared with Brown's chloro-dicyclohexylborane/tertiary amine system have been shown to react with achiral aldehydes in a highly stereoselective way to yield a 1,2-syn/1,3-syn stereoisomer. Through oxidative cleavage of the aldol adducts with periodic acid hydrate, enantiopure syn-α,β-dihydroxy esters with either hydroxyl group differently protected have been prepared. These erythrulose derivatives therefore behave as a chiral hydroxy acetate (glycolate) enolate equivalent.
Preparation and characterization of new low melting ammonium-based ionic liquids with ether functionality
2009
Abstract Eighteen new and three previously known but insufficiently characterized RR´3N+A− and R2R´2N+A− type (R = 2-ethoxyethyl or 4-methoxybenzyl, R´ = methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, A = Br, BF4 or PF6) quaternary ammonium (QA) salts were synthesized and characterized by using 1H and 13C NMR techniques, mass spectroscopy and elemental analysis. The bromide salts were synthesized either by treating dimethyl formamide with an ether functionalized alkyl bromide in the presence of potassium carbonate or by treating a tertiary amine with an ether functionalized alkyl bromide. The QA tetrafluoroborates and hexafluorophosphates were synthesized by metathesis reaction betw…
Nucleophilic substitutions in the isoindole series as a valuable tool to synthesize derivatives with antitumor activity
2011
Abstract A novel synthetic approach to the synthesis of 3-substituted isoindoles through nucleophilic substitution of 3-halo derivatives by charged carbon, and neutral nitrogen, oxygen, and sulfur nucleophiles, assisted by a 1-acyl group, is reported. Aryl-thio-isoindoles, obtained through a direct nucleophilic substitution with sulfur nucleophiles, showed cytotoxic activity, with GI50 values from micromolar to sub-micromolar concentrations, against the total number of cell lines investigated.
First reactions of dialkoxycarbenium tetrafluoroborates with pyrroles, 5H-dibenz[b,f]azepines, and electron-rich arenes
2009
Pyrrole (2a) and 2,5-dimethylpyrrole (2b) react with the dialkoxycarbenium tetrafluoroborates 1a-1c under kinetic control to yield the corresponding acylpyrrole derivatives. 5H-Dibenz[b,f]azepine (9a) and the 10,11-dihydro derivative 9b react only with the most electrophilic of the series of electrophiles tested, namely, diethoxycarbenium tetrafluoroborate (1a), to furnish the corresponding formyl derivatives. Similarly, in arene chemistry, the highly electron-rich N,N-dimethylaniline (13a) and 1,3,5-trimethoxybenzene (13b) are formylated by reaction with 1a.
Dienediolates of unsaturated carboxylic acids in synthesis. Aldehydes and ketones from alkyl halides, by ozonolysis of β,γ-unsaturated α-alkyl carbox…
1997
Abstract A convenient two-step procedure for a two carbon homologative conversion of alkyl halides into aldehydes and methyl ketones by α-alkylation of unsaturated carboxylic acids, followed by ozonolysis is developed and applied to the synthesis of ω-chloro aldehydes. Triethylamine is superior to dimethyl sulfide or triphenylphosphine for cleavage of the ozonides, except when aldol condensation side reactions require use of protic solvents and iodide salts. Cleavage of the ozonides by triethylamine is shown to occur mainly through a reductive process.
Oxidation-responsive polyether block copolymers lead to non-ionic polymer surfactants with multiple amine N-oxides
2019
Block copolymers consisting of a nonpolar poly(propylene oxide) block and a poly(glycidyl amine) block were prepared by anionic ring-opening polymerization (AROP). The tertiary amine groups of the block copolymers were quantitively transformed into the corresponding zwitterionic amine N-oxides, as confirmed by 1H NMR and 15N NMR spectroscopy. This leads to strongly amphiphilic polyether block copolymers with multiple N-oxides. Full oxidation of the amine groups was also possible in situ in an emulsion, demonstrating the oxidation-responsive character of this new class of non-ionic polymeric surfactants.
The anionic copolymerization of 5-(N,N-diisopropylamino)isoprene with styrene
1995
The anionic copolymerization of 5-(N,N-diisopropylamino)isoprene (N,N-diisopropyl-2-vinylallylamine) and styrene initiated with alkyllithium compounds is studied. Copolymers obtained from different compositions are characterized by size-exclusion chromatography (SEC), differential scanning calorimetry and by 1 H NMR and 13 C NMR spectroscopy. Under these conditions the dialkylaminoisoprene, similar to butadiene and isoprene, is more reactive than styrene and is incorporated faster into the polymer backbone. The incomplete conversion of the monomers has been attributed to the formation of intra-or intermolecular complexes between the Li + counterion at the chain end and amino groups. Because…
One‐Dimensional Coordination Polymers of Mn II , Cu II , and Zn II Supported by Carboxylate‐Appended (2‐Pyridyl)alkylamine Ligands – Structure and Ma…
2009
Four new complexes [MnII(L1OO)(H2O)][ClO4]·2H2O (1), [ZnII(L1OO)][ClO4]·2H2O (2), [CuII(L3OO)][CF3SO3]·H2O (3), and [ZnII(L3OO)][ClO4] (4) (L1OO– = 3-[(2-(pyridine-2-yl)ethyl){2-(pyridine-2-yl)methyl}amino]propionate; L3OO– = 3-[(2-(pyridine-2-yl)ethyl){(dimethylamino)ethyl}amino]propionate) have been synthesized and characterized by elemental analysis, IR, and UV/Vis spectroscopy. Structural analysis revealed that 1, 3, and 4 are one-dimensional chain-like coordination polymers. In 1 distorted octahedral MnN3O3 and in 3 square-pyramidal CuN3O2 coordination is satisfied by three nitrogen atoms and an appended carboxylate oxygen atom of the ligand, and an oxygen atom belonging to the carboxy…
A new access to 2′-amino-substituted vinylindoles as donor-activated heterocyclic dienes and their first diels-alder reactions
1992
Abstract Reactions of the 3-acylindoles 5, 10 , and 15 with α-amino-α′-diphenylphosphinoyl-substituted carbanions gave rise to the 2′-amino-substituted 3− and 2-vinylindoles 7, 12 , and 17 by way of the isolable carbinols 6 , 11 , and 16 . The heterocyclic dienes 7 , 12 , and 17 readily underwent Diels-Alder reactions with N -phenylmaleimide.