作者:Palwinder Singh、Kamaldeep Paul
DOI:10.1002/jhet.5570430313
日期:2006.5
substituted/-unsubstituted barbituric acids with various alkyl dihalides under phase transfer catalytic conditions using DMF-K2CO3 (base), TBAHSO4 (catalyst) provide spirobarbituric acids in moderate to high yields. Irrespective of the existence of C5-monoalkylated compounds in the enolic form (confirmed by the isolation of some of its analogues), the second alkylation predominantly takes place at C5. The underlying
在相转移催化条件下,使用DMF-K 2 CO 3(碱),TBAHSO 4(催化剂),N,N'-取代/未取代的巴比妥酸与各种烷基二卤化物的单步反应可提供中等至高收率的螺巴比妥酸。不管烯醇形式的C 5-单烷基化化合物是否存在(通过分离某些类似物确认),第二个烷基化反应主要发生在C 5处。讨论了反应的基本机理。5,7-二甲基-5,7-二氮杂螺[2.5]辛烷-4,6,8-三酮与NaCN,PhSH,HS(CH 2)2 OH和Br 2一起开环 提供5-单烷基化的巴比妥酸酯,否则难以通过巴比妥酸的常规烷基化来制备。