Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The synthesis of N-protected 5-oxazolidinones using amino acids, paraformaldehyde and p-toluene sulfonic acid in a minimum amount of toluene accelerated by microwave irradiation for 3 min in high yield is described. ... The synthesis of N-protected oxazolidinones using N-protected amino ...