Electrophilic cyclization and thermal rearrangement of allylic 1,1-dimethylisoureas

Article abstract of DOI:10.1055/s-1991-26388

A series of substituted 2-allyl-1,1-dimethylisoureas (allyl N,N-dimethylcarbamimidates) was prepared by the reaction of the corresponding allylic alcohols with dimethylcyanamide in the presence of sodium hydride. Treatment of the isoureas with mercuric acetate in acetonitrile, followed by reduction with sodium borohydride, afforded substituted 4,5-dihydrooxazoles. Thermal rearrangement of the 1,1-dimethylisoureas occurred in refluxing xylene to give trisubstituted ureas.