The invention provides novel .beta..sub.2 adrenergic receptor agonist compounds of formula (I): ##STR00001## wherein R.sup.1 R.sup.13 and w have any of the values described in the specification. The invention also provides pharmaceutical compositions comprising such compounds, methods of using such compounds to treat diseases associated with .beta..sub.2 adrenergic receptor activity, and processes and intermediates useful for preparing such compounds.