Acid-promoted reactions in 1-hydroxy, 1-dimethylaminomethyl and 1-methylene-4-arylmethyl-2,4-dihydro-1H-pyrazino[2,1-b]-quinazoline-3,6-diones
Acid-promoted reactions in 1-hydroxy, 1-dimethylaminomethyl and 1-methylene-4-arylmethyl-2,4-dihydro-1H-pyrazino[2,1-b]-quinazoline-3,6-diones
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DOI：
10.1016/s0040-4020(02)00619-1
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发表时间：
2002-07-29
期刊：
影响因子：
2.1
通讯作者：
Avenda単o, C
中科院分区：
文献类型：
--
作者：
Heredia, ML;de la Cuesta, E;Avenda単o, C
标题化合物的1-二甲基氨基甲基或1-亚甲基通过Mannich或Mannich-Hofmann串联反应作为方案的最后一步引入，该方案比先前描述的用于这些N-酰基化合物的前体的其它方案短。在这些化合物中，酸促进的Pictet-Spengler型分子内环化反应仅限于N（2）-未取代的化合物，而它们的N（2）-甲基取代的类似物则得到二聚化产物。1-羟基-1，2-二取代的化合物是通过与2 H，4 H-吡嗪并[2，1-B]-喹唑啉-1，3，6-三酮加成而得到的。(C)2002爱思唯尔科技有限公司。保留所有权利。
The 1-dimethylaminomethyl or 1-methylene group of the title compounds was introduced through a Mannich or a tandem of Mannich-Hofmann reactions as the final step of a protocol that is shorter than other previously described for these precursors of N-acyliminium species. In these compounds, the acid-promoted intramolecular cyclizations of Pictet-Spengler-type were restricted to the N(2)-unsubstituted compounds, while their N(2)-methyl substituted analogues gave instead dimerization products. The cyclization was effective with 1-hydroxy-1,2-disubstituted compounds, which were obtained through addition of a Grignard reagent to 2H,4H-pyrazino[2,1-b]-quinazoline-1,3,6-triones. (C) 2002 Elsevier Science Ltd. All rights reserved.