The reaction of 1-carbamoylisatins 2 with 2-ethyl-2-isothiourea hydrobromide in the presence of triethylamine followed by acid-catalyzed cyclization of the resulting 4-(2-ethyl-2-isothioureido)carbonyl-3, 4-dihydro-4-hydroxy-2(1H)-quinazolinones 7 provides a general and high-yielding route to 3'-substituted spiro[imidazolidine-4, 4'(1'H)-quinazoline]-2, 2'5(3'H)-triones 8.
在
三乙胺存在下,1-
氨基甲酰基异沙丁鱼苷 2 与 2-乙基-2-异
硫脲氢溴酸盐反应,然后在酸催化下环化生成 4-(2-乙基-2-异
硫脲基)羰基-3.4-二氢-
4-羟基-2(1H)-
喹唑啉酮 7、4-二氢-
4-羟基-2(1H)-
喹唑啉酮 7 提供了一条通向 3'-取代的螺[
咪唑烷-4,4'(1'H)-
喹唑啉]-2,2'5(3'H)-三酮 8 的通用高产路线。