新型1,6-二取代-5,6-二氢吡咯并[1,2-f]蝶啶衍生物的合成

Synthesis of Novel 1,6-Disubstituted-5,6-dihydropyrrolo[1,2-f]pteridines

以Pictet-Spengler型反应为基础,设计了一条简便的合成1,6-二取代-5,6-二氢吡咯并[1,2-f]蝶啶衍生物的方法.以4,6-二氯-5-氨基嘧啶为起始原料,经Clauson-Kaas反应、胺亲核取代两步反应合成了4-氨基-6-氯-5-(1H-吡咯-1-基)-嘧啶,然后与醛或脂肪酮在对甲苯磺酸催化下,发生亲电关环得到1-氯-5,6-二氢-6-取代吡咯并[1,2-f]蝶啶,其1位氯原子具有较高的反应活性,易于被胺类亲核试剂取代.

A methodology to prepare novel 1,6-disubstituted-5,6-dihydropyrrolo- [ 1,2-f] pteridine derivatives has been developed. The key in this synthesis is a Pictet-Spengler type reaction. The Clauson-Kass reaction of 4,6-dichloro-5-amino-pyrimidine with 2,5-dimethoxyltetrahydrofuran, followed by amination of one of the chloro groups, resulted in 4-amino-6-chloro-5- （ 1H-pyrrol-1 -yl） pyrimidine. Subsequently, 4-amino-6-chloro-5-（1H-pyrrol-1-yl） pyrimidine reacted with an aldehyde or aliphatic ketone in the presence of toluenesulfonic acid in refluxing toluene to yield an imine intermediate, which underwent an intramolecular electrophilic substitution to lead to the corresponding dihydropyrrolo[ 1,2-f] pteridines in moderate to good yields. The chloro group on the newly formed heterocycle could be readily replaced by a nucleophile, such as an amine. This strategy provides a convenient way to access to a class of heterocyclic compounds with possible interesting biological activities.