Synthesis and bronchodilatory activity of some nitrogen bridgehead compounds

A series of tricyclic nitrogen bridgehead compounds 7-22 have been synthesised and evaluated for their in vitro bronchodilatory activity using isolated guinea pig tracheal chain, precontracted with acetylcholine. The relaxant effect of 2,3,4,5-tetrahydroazepino[2,1-b]-8,9-dimethoxyquinazolin-11(1H)-one (7) (DPJ-386) was greater than that of theophylline, aminophylline and quinazoline derivative 3, which lacks methoxy groups at positions 8 and 9. Various nitrogen containing functionalities such as benzylamino, acetamido, benzamido and phthalimido were also introduced at 9 position of 3. This resulted in loss of relaxation activity in precontracted guinea pig tracheal chain. These results show that the better relaxation property possessed by compound 7 hydrochloride is due to methoxy groups at 8 and 9 positions. (C) 2002 Published by Editions scientifiques et medicales Elsevier SAS.