This invention relates to compounds of formula I: ##STR00001## wherein R.sup.1 and R.sup.2 are as defined in the specification, or a pharmaceutically acceptable salt or solvate or stereoisomer thereof. The invention also relates to pharmaceutical compositions and combinations comprising such compounds, processes and intermediates for preparing such compounds, and methods of using such compound to, for example, treat pulmonary disorders, such as chronic obstructive pulmonary disease and asthma.