81569-31-5Relevant articles and documents
The Preparation of Thiazole-4- and -5-carboxylates, and an Infrared Study of their Rotational Isomers
Barton, Anne,Breukelman, Stephen P.,Kaye, Perry T.,Meakins, G. Denis,Morgan, David J.
, p. 159 - 164 (2007/10/02)
Convenient general procedures have been developed for preparing series of thiazole-4- and -5-carboxylates containing alkyl and halogeno substituents.While both series of esters show i.r. carbonyl doublets caused by rotational isomerism, the more intense absorptions of the 4-carboxylates are the lower wavenumber components, whereas those of the 5-carboxylates are the higher wavenumber components.In both series the stronger bands arise from the thermochemically more stable forms; identification of these forms as the carbonyl O,S-syn-s-trans rotamers is more certain with the 4-carboxylates than with the 5-carboxylates.