Pfizer Inc.
Tricyclic Compounds And Their Use As Phosphodiesterase Inhibitors

Abstract:

The present invention is directed to compounds of Formula I: ##STR00001## or a pharmaceutically acceptable salt thereof, wherein the substituents A, R.sup.1, R.sup.2, R.sup.3a, R.sup.3b, R.sup.4a, R.sup.4b and n are as defined herein. The inventions also directed to pharmaceutical compositions comprising the compounds, methods of treatment using the compounds and methods of preparing the compounds.