Synthesis of novel and biologically potent heteropolycyclics containing bridge head nitrogen

Abstract magnified image A facile one pot synthesis of 2,3,4,5‐tetrahydropyrido [1,2‐a] [1,3] diazepine‐2,5‐dione2and 3,4‐dihydro‐2H‐pyrido [1,2‐a] pyrimidine‐2,4‐dione3has been achieved. Condensation of3witho‐aminobenzaldehydes produced the linear product4and not the angular one5. Cyclocondensation of3with 1,5‐diketones afforded a tricyclic linear system6, a bis assembly system7and two novel heterotetracyclic nitrogen bridged linear systems8and10. Condensation ofo‐aminobenzaldehydes with2produced a novel linear system12and a new doubly fused hexacyclic system11. Cyclodehydration of2with 1,2‐dicarbaldehydes produced1,13, and a new heterotetracyclic nitrogen bridged system14. Condensation of3with aromatic aldehydes in presence of ethylene glycol as solvent without the use of catalyst generated the doubly nitrogen bridged linear pentacyclic systems15,16,17. The synthesized compounds have been adequately characterized and screened for bronchodilatory and antimicrobial activities with promising results. J. Heterocyclic Chem., (2010).