The present invention relates to compounds of formula 1 ##STR00001## wherein the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, n, m and X may have the meanings given in the claims and in the specification, and the use thereof as pharmaceutical compositions, particularly for the treatment of inflammatory and obstructive respiratory complaints.