| Popis: |
This paper deals with the kinetic measurement of the reaction between formaldehyde and the amides of carboxylic acids and urea. It is shown that the formation of a methylol amide proceeds by a bimolecular reaction, while its decomposition is a monomolecular reaction. The reactions are catalysed by H3O+ and OH− ions and show general acid catalysis. General base catalysis was found in the urea-formaldehyde system, but could not be detected in reactions of formaldehyde with amides of carboxylic acids. A mechanism for the reactions of formaldehyde with amides in general (including urea) is proposed. In strongly alkaline solution the rates of decomposition of methylol amides were found to be independent of the hydroxyl ion concentration. The acid dissociation constant of some methylol amides have values of about 10−14 moles 1−1 at 0° C. |
