摘要:
It was found that adducts of 3'-aroyl-4'-hydroxyspiro[indole-3,2'-furan]-2,5'(1H)-diones with tetramethylguanidine are formed when equimolar amounts of methyl aroylpyruvates, isatin, and N,N,N',N'-tetramethylguanidine are heated briefly in dioxane.