3-Substituted imidazolidin-Zone-1-carbony1 chlorides (SICs) are very important intermediates for the semi-synthesis of p-lactam antibiotics.'-6 SICs have been conveniently prepared by the reaction of N-substituted imidazolidin-2-ones with phosgene.'-'However, phosgene has become commerically inaccessible as a common and useful reagent because it is a highly toxic, dangerous gas. Such a situation prompted us to investigate a ...
