Morpholine

About: Morpholine is a research topic. Over the lifetime, 5411 publications have been published within this topic receiving 51063 citations. The topic is also known as: diethylene imidoxide & diethylene oximide.

Synthesis, structure, and electrochemistry of cobalt(III) complexes with bis(benzoylacetone)ethylenediimine Schiff base

Abstract: A series of complexes of the type trans-[Co((BA)2en)(amine)2]ClO4 — where (BA)2en is the bis(benzoylacetone)ethylenediimine dianion and the amines are morpholine (mrpln) 1, aniline (aniln) 2, benzylamine (bzlan) 3, piperidine (pprdn) 4, p-toluidine (p-toldn) 5, and pyrrolidine (prldn) 6 — has been synthesized and characterized by elemental analysis, UV–vis, 1H NMR, and 13C NMR spectroscopy. The crystal and molecular structure of trans-[Co((BA)2en)(mrpln)2]ClO4 (1) has been determined by X-ray crystallography. The electrochemical reduction of these complexes at a glassy-carbon electrode, in the potential range of 0.5 to –2.0 V (vs. Ag/AgCl), in acetonitrile solution, indicates that the first reduction potential of Co(III/II) is irreversible, which is accompanied by the dissociation of the axial amine–cobalt bonds. This potential is dependent on the pKa of the axial amines. The second reduction potential of Co(II/I) shows reversible behavior and is also independent of the axial amine pKa. These results indi...

Synthesis and Characterisation of Amine Adducts of Tri(4-bromophenyl) boroxine, Tri(3-nitrophenyl)boroxine, and Tri(3-aminophenyl)boroxine; Molecular Structure of 3-Picoline·tri(4-bromophenyl)boroxine

Abstract: Twenty five 1:1 adducts of the triarylboroxines (4-BrC6H4)3B3O3 (PBB) (3-NO2C6H4)3 B3O3 (MNB), and (3-NH2C6H4)3B3O3 (MAB) with N donor ligands (cyclohexylamine, 4-picoline, 3-picoline, piperidine, morpholine, isobutylamine, triethylamine, pyridine, of ligand and triarylboroxine in Et2O at room temperature. All 25 adducts have been characterised by elemental analysis, Mpt, IR and by 1H and 13C NMR. MNB and 4 of its adducts have been characterised by 11B MAS NMR. In solution variable temperature 1H NMR of selected PBB derivatives and of MNB-cyclohexylamine indicate that a ligand dissociation-recombination process is occuring with ΔG+ of ca. 39–54 kj·mol 1. The crystal and molecular structure of 3-picoline PBB has been determined by a single-crystal X-ray diffraction study. The colourless compound crystallises in the orthorhombic space group (Pbca) with a = 14.1710(10), b = 15.446(5), and c = 22.418(7) A, with Z = 8, calculated density = 1.737 Mg/M3, and final R values [I > 2 σ(I)] of R1 = 0.0376, and wR 2 =...

Convenient route to enantiopure fmoc-protected morpholine-3-carboxylic acid.

Abstract: Enantiopure Fmoc-protected morpholine-3-carboxylic acid was synthesized from dimethoxyacetaldehyde and serine methyl ester through a short and practical synthetic route. The preparation consisted of a five-step process based on reductive amination, intramolecular acetalization, and concomitant elimination of the anomeric methoxy substituent, followed by hydrogenation of the double bond and final acidic ester hydrolysis. The optical purity of both enantiomers of the title amino acid was demonstrated by HPLC analysis of the corresponding amide derivatives obtained from coupling with chiral (S)-(-)-1-phenylethylamine. Moreover, the synthesis of a model tripeptide showed full compatibility of the title Fmoc-amino acid with solid-phase peptide synthesis, thus allowing the application of Fmoc-morpholine-3-carboxylic acid in peptidomimetic chemistry on the solid phase.