Electrophilic Cyclization and Thermal Rearrangement of Allylic 1,1-Dimethylisoureas
作者:Robert M. Giuliano、Tien T. Duong、Ted W. Deisenroth、Wayne G. Mcmahon、Walter J. Boyko
DOI:10.1055/s-1991-26388
日期:——
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.
通过相应的烯丙醇与二甲基氰酰胺在氢化钠存在下反应制备了一系列取代的2-烯丙基-1,1-二甲基异脲(烯丙基N,N-二甲基氨基甲酸酯)。 用乙腈中的乙酸汞处理异脲,然后用硼氢化钠还原,得到取代的4,5-二氢恶唑。 1,1-二甲基异脲在回流二甲苯中发生热重排,得到三取代脲。