Compounds of the formula ##STR1## wherein A is a single bond, ##STR2## R.sub.1 is --OH, --0--acyl, chlorine or hydrogen; R.sub.2 is hydrogen, methyl or ethyl;R.sub.3 is ##STR3## m is 2, 3 or 4; n is 1, 2 or 3;R.sub.4 is hydrogen or lower alkyl;R.sub.5 is hydrogen, lower alkyl or, when R.sub.4 is hydrogen, also phenyl;R.sub.6, R.sub.7 and R.sub.8 are each hydrogen or methyl;R.sub.9 is hydrogen, --Ar, --OAr or --NH--CO--Ar;Ar is ##STR4## R.sub.10, R.sub.11 and R.sub.12 which may be identical to or different from each other, are each hydrogen, hydroxyl, methyl, methoxy, halogen, methylenedioxy, --NH--R.sub.13 or --CONH.sub.2 ; andR.sub.13 is hydrogen, acyl or lower alkylsulfonyl;and non-toxic, pharmaceutically acceptable acid addition salts thereof; the compounds as well as their salts are useful for the treatment of asthma, bronchitis, urticaria, conjunctivities, hay fever, colds and cardiovascular disorders, and for relaxation of the uterine musculature.