Abdul-Hussain Khuthier

Decomposition of prop-2-ynylic N-oxides to acrolein and schiff bases via O-allenyl hydroxylamines

Abstract Prop-2-ynylic N-oxides rearrange thermally via O-allenyl hydroxylamines to acrolein and an imine. The second rearrangement step, falling in the class of thermal cis -eliminations, is shown with variously 2 H-substituted pargyline N-oxides.

Rearrangement of prop-2-ynylic N-oxides to O-allenyl hydroxylamines

Rearrangement of N-prop-2-ynylpiperidine N-oxide and N-prop-2-ynylmorpholine N-oxide to the corresponding O-allenyl hydroxylamines is reported; this rearrangement appears to be intramolecular proceeding by a cyclic mechanism.

Synthesis and characterization of some olefin/phosphine-tert-amine N-oxide platinum(II) complexes

Abstract Eighteen olefin (or tert-phosphine)-tert-amine N-oxide platinum(II) complexes of the general formula trans-[PtL(tert-amine N-oxide)Cl2] have been prepared, where L is ethylene, styrene, or triethylphosphine. The tert-amine N-oxides used in the complexation were of the N-aryl saturated heterocyclic type substituted at the ortho- or para-position with an electron withdrawal group, i.e. NO2, CN, COCH3, COC6H5, and COOC2H5. The complexes were characterized by elemental analysis, IR, and 1H NMR spectroscopy. Linear relationships were obtained between the stretching frequencies of the NO bonds of the platinum complexes and Hammet constants, viz. σ and σ , which indicate the presence of inductive and field effects for the para-substitution.

13C Nuclear magnetic resonance spectra of some N-alkylpiperidines and the corresponding N-oxides. N-Substitution and N-oxidation effects

Carbon-13 nuclear magnetic resonance spectra were measured for 16 N-alkyl-C-methyl piperidines and 14 of the corresponding N-oxides. The observed chemical shifts of the ring carbons were analysed in terms of the bulkiness of the N-alkyl substituent. The N-oxidation effect on the chemical shifts of the ring and alkyl carbons was calculated.

Studies of Tertiary Amine Oxides. Part1 15. Carbon - 13 nuclear magnetic resonance spectra of some N-(4-substituted phenyl) piperidine, the corresponding N-oxides, and their thermal-rearrangement product

Abstract The carbon-13 chemical shifts of seven N-(4-substituted phenyl) piperidine; the corresponding N-oxides, and their thermal rearrangement products were analyzed and assigned. The N-oxidation effect on the carbon-13 chemical shift is discussed, a correlation of N-oxidation effect with substituent constant (σp, σm, σI and σR) has been studied; dual substituent-parameter equation produce better correlation.

Carbon-13 Nuclear Magnetic Resonance Spectra of Some N-(2,4-dinitrophenyl) Amines, The Corresponding N-Oxides, and Their Thermal Rearrangement Products

Abstract Carbotn-13 NHR assignment of eight N-(2,4- dinitrophenyl) amines was achived. She six corresponding N- Oxides and their thermal rearr-angement products were also analyzed. The N-oxidation effect on the carbon-13 chemical shift is discussed.

Studies of tertiary amine oxides. Part 14. Protic solvent effects on the rate of thermal rearrangement of N-(2,4-dinitrophenyl)piperidine N-oxide

The rate of rearrangement of N-(2,4-dinitrophenyl)piperidine N-oxide has been studied in 15 hydroxylic solvents. The first-order rate coefficients (kobs) have been successfully correlated with different solvent parameters. The results are explained in terms of the nucleophilic solvation capability of the solvent which in turn supports the previously proposed three-membered ringactivated complex. Moreover, the role of the HBD ability of the solvent in this reaction is also pronounced, particularly since reaction in alcohols exhibits lower reactivity and higher enthalpy and entropy of activation compared with aprotic solvents.

Carbon-13 NMR study of some acetylenic amines, the N-oxides and their rearrangement products

Abstract Carbon-13 NMR chemical shifts of some N , N -dialkyl-4-acetoxybut-2-ynylamines and their corresponding N -oxides have been analysed. These N -oxides undergo thermal rearrangement to O -allenyl hydroxylamine for which the 13 C NMR spectral assignments were also carried out. The effect of N -oxidation on the chemical shifts is calculated.

Iodometric determination of aryldialkylamine-N-oxides

A simple, rapid and selective titrimetric procedure for the determination of 0.1–20 mg of aryldialkylamine has been developed. The method is based on the reduction of the aryldialkylamine oxides with iodide in acidic medium. The rate of reaction is accelerated by heating the reactants just to boiling, and after cooling the reaction products, the liberated iodine is titrated with thiosulphate solution, with starch as indicator. The method can be applied successfully to the determination of aryldialkylamine oxides in the presence of aliphatic and aromatic amine oxides and amines.

Studies of tertiary amine oxides. Part 8. Rearrangement of N-(2,4-dinitrophenyl)-piperidines and -morpholine N-oxides in aprotic solvents

The N-oxides of N-(2,4-dinitrophenyl)-piperidines and -morpholine undergo thermal rearrangement to the substituted hydroxylamines. The kinetics of the rearrangement were studied in aprotic solvents at four or five temperatures. Steric and polar factors have great influence on the rate of rearrangement. The kinetic results together with cross-over experiments are in full agreement with an intramolecular cyclic mechanism (SNi).