Regioselective Synthesis of 7,8-Dihydropyrrolo[1,2-a]pyrimidin-4(6H)-ones and 7,8-Dihydropyrrolo[1,2-a]pyrimidin-2(6H)-ones
作者:Monica Donghi、Silvia Pesci、Vincenzo Summa、Uwe Koch、Stephane Spieser、Cristina Gardelli
DOI:10.1055/s-0029-1218566
日期:2010.1
Annulated analogues of 5,6-dihydroxypyrimidine-4-carboxylate ester and 5,6-dihydroxypyrimidine-4-carboxylamide were synthesized. The intermediary homoallylic amines were subjected to a ring-closure reaction under different reaction conditions. A notable pH-dependency of the ring closure leading to regioisomeric tetrahydropyrrolo[1,2-a]pyrimidines was observed. Treatment with dimethyldioxirane and base led to 3-hydroxy-4-oxo-4,6,7,8-tetrahydropyrrolo[1,2-a]pyrimidines while m-chloroperbenzoic acid or NBS afforded 3-hydroxy-2-oxo-2,6,7,8-tetrahydropyrrolo[1,2-a]pyrimidines.
合成了5,6-二羟基嘧啶-4-甲酸酯和5,6-二羟基嘧啶-4-甲酰胺的环状类似物。中间体高烯丙胺在不同的反应条件下进行闭环反应。观察到导致区域异构四氢吡咯并[1,2-a]嘧啶的闭环的显着pH依赖性。用二甲基二环氧乙烷和碱处理得到3-羟基-4-氧代-4,6,7,8-四氢吡咯并[1,2-a]嘧啶,而间氯过苯甲酸或NBS得到3-羟基-2-氧代-2, 6,7,8-四氢吡咯并[1,2-a]嘧啶。