Selenium-containing heterocycles: Part 2. Reactions of 3-amino-4,6-dimethyl-selenolo[2,3-b]pyridine-2-carbonitrile and related fused tetracyclic systems

Abstract

A novel series of pyrido[3’,2’:4,5]selenolo[3,2- d]pyrimidine, 7,9-dimethylpyrido [3’,2’:4,5]selenolo[3,2- d]pyrimidine-2,4-( 1H,3H)-dithione, 7,9-dimethylpyrido[3’,2’:4,5]selenolo[2,3- e]tetrazolo[1,5- c]pyrimidine-6( 5H)-thione, 9,11-dimethyl-pyrido[3’,2’:4,5]selenolo[2,3- e][1,2,4]triazolo[1,5- c]pyrimidine, 7,9-dimethylpyrido[3’,2’:4,5]selenolo[2,3- e]imidazo[1,2- c] pyrimidine and 10,12-dimethylpyrido[3″,2″:4’,5']selenolo[3’,2’:4,5]pyrimido[1,6- a]pyrimidine derivatives were prepared from 3-amino-4,6-dimethylselenolo[2,3- b]pyridine-2-carbonitrile.

Advances in the chemical and biological diversity of heterocyclic systems incorporating pyrimido[1,6-a]pyrimidine and pyrimido[1,6-c]pyrimidine scaffolds

“…A simple multi-step synthetic method was reported by Abdel-Hafez et al 88 for the preparation of a tetracyclic system incorporating the pyrimido[1,2- c ]pyrimidine scaffold. Thus, 3-amino-4,6-dimethyl-selenopheno[2,3- b ]pyridine-2-carbonitrile (107) was prepared by reaction of 2-hydroseleno-4,6-dimethyl-nicotinonitrile (106) with 2-chloroacetonitrile.…”

“…In this cyclization, the terminal amino group of the propyl chain acts as a nucleophile which attacks the C NH at position 4 of the pyrimidine ring, resulting in the elimination of an ammonia molecule ( Scheme 26 ). 88 …”

“…A simple multi-step synthetic method was reported by Abdel-Hafez et al 88 The reaction of enaminonitriles of thiophenes 111a-e with formic acid at reux temperature yielded thienopyrimidinones 112a-e, respectively. 90 Further treatment of 112a-e with phosphorus oxychloride under microwave irradiation conditions yielded the anticipated chlorinated thienopyrimidines 113a-e. A series of 7H-thienopyrimidoquinazolinones 115a-o was synthesized by Niementowski reactions 91 of 3a-e with anthranilic acids 114a-c under microwave irradiation or reux [92][93][94][95] conditions.…”