Abstract: Compounds of the formula ##STR1## wherein: R.sub.1 is cyano or nitro;R.sub.2 and R.sub.3 are independently hydrogen or lower alkyl; andR.sub.4 is alkyl; alkenyl; optionally substituted phenyl or phenyl lower alkyl; --(CH.sub.2).sub.m OR.sub.2 or --(CH.sub.2).sub.m N(R.sub.2).sub.2 ; wherein m is an integer of 1-5 and R.sub.2 is as defined above;or a pharmaceutically acceptable ester thereof; are smooth muscle relaxants, particularly useful in the treatment of hypertension.

Abstract: New compounds of formulas I and II ##STR1## and the pharmaceutically acceptable acid addition salts thereof, wherein M is selected from the group consisting of hydrogen, morpholino, benzylamino, di-n-lower alkylamino, n-lower alkylamino and ##STR2## wherein Ar is optionally substituted phenyl; Z.sub.1 and Z.sub.2 are each independently selected from the group consisting of CH.sub.2, CHOB and C.dbd.O, wherein B is selected from the group consisting of hydrogen and alkanoyl;Y is oxygen or nothing;n is an integer from 0-4 but cannot be zero when Z.sub.1 is CHOB;m is an integer from 0-4 but cannot be zero when Z.sub.2 is CHOB;R.sub.1, R.sub.2 and R.sub.3 are each independently hydrogen, halogen, hydroxy, trifluoromethyl, alkyl or alkoxy;R.sub.4 is lower alkyl; andR.sub.5 is hydrogen or lower alkyl,are antihistamines and are therefore useful in the treatment of respiratory diseases including asthma, hay fever, allergies and the common cold. They are also vasodilators.