Dual antagonists of platelet activating factor and histamine - 3. Synthesis, biological activity and conformational implications of substituted N-acyl-bis-arylcycloheptapiperazines.

A series of N-acyl-4-(5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11 -ylidene)piperazines is described that an dual antagonists of PAF and hista mine. The structural requirements for activity in this series parallel thos e of their previously reported piperidinylidene counterparts. Whereas their global minimum energy conformations are different for both series of compo unds, computer assisted molecular modeling suggests that a common bioactive conformation is possible. (C) 1998 Elsevier Science Ltd. All rights reserv ed.