Dual standard addition for quantitative NMR analysis

A technique is described for quantitative NMR measurement which involves the use of a pair of internal standards. This procedure overcomes several of the problems encountered with only one standard material. A computer programme is described for statistical treatment of the results.     

Electron impact mass spectra of 2-[acyl(alkyl)amino]oxazoles

The mass spectral behaviour of 2-methyl-N-butyl-N-(4-methyloxazol-2-yl)propanamide is characterized by cleavage of the acylamino substituents and the elimination of a hydroxyl radical. An understanding of this elimination has been obtained from the analysis of further 2-[acyl(alkyl)amino]oxazoles and the use of deuterium labelled compounds.     

Lanthanide shift reagents. IX. Proton and carbon magnetic resonance study of specific contact interactions of a bifunctional oxazole amide with fluorinated lanthanide shift reagents

Highly specific proton line-broadening and paramagnetic ¹³C shifts observed for N-butyl-N(4-methyloxazol-2-yl)-2-methylpropionamide in the presence of fluorinated lanthanide shift reagents, are absent when non-fluorinated reagents are used. This unusual behaviour is rationalized in terms of possible chelation of the N-butyl-N(4-methyloxazol-2-yl)-2-methylpropionamide to the lanthanide reagent, causing transfer of the unpaired electron into the heterocyclic ring.