Rearrangements in metastable ion decompositions of protonated propylamines
摘要:
AbstractDecomposition of nPrNH3+ to NH4+ does not occur via vicinal elimination. Hydrogen transfer takes place from all positions of the alkyl chain. Intermediacy of either an ion–neutral complex. [iPr+ NH3], or rearrangement to iPrNH3+ is required. SCF calculations were used to probe the potential energy surface. There is a minimum corresponding to [iPr+ NH3], in which the nitrogen lone pair points towards the machine hydrogen and is 2.1 Å away from it, and another, less stable, minimum corresponding to a hydrogen‐bonded structure, H3N …︁ H3CCHCH3+, in which one methyl hydrogen is 2.0 Å from the nitrogen. Density of states estimates suggest that avibrationally excited complex can live for the order of 100 ps before either collapsing to iPrNH3+ or yielding NH4+ and propene.
This report presents an efficient synthesis of D6 -clenproperol and D6 -cimaterol with 99.5% and 99.7% isotopic abundance in acceptable yields and excellent chemical purities with deuterium isopropylamine as labelled precursor. Their structures and the isotope-abundance were confirmed by proton nuclear magnetic resonance and liquid chromatography-mass spectrometry.
showed promising antiplasmodial activity, but poor microsomal stability, several strategies were investigated to improve the metabolic stability of the compounds. This included the introduction of fluorine or deuterium atoms, as well as carbocyclic groups. Among the new compounds, the 2-aminocyclobutyl derivative 5g demonstrated enhanced microsomal stability compared to compound 1, while retaining antiplasmodial