Piperazine derivatives of theophylline

Abstract

New compounds of the formula ##STR1## and the pharmaceutically acceptable acid addition salts thereof, wherein M is selected from the group consisting of hydrogen, morpholino, benzylamino, di-n-lower alkylamine, n-lower alkylamine, and aryl piperazino; 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 sulfur; 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, or when m is hydrogen; R.sub.1, R.sub.2 and R.sub.3 are each independently hydrogen, halogen, hydroxy, trifluoromethyl, alkyl or alkoxy; and R.sub.4 and R.sub.5 are each independently lower alkyl, with the proviso that both R.sub.4 and R.sub.5 cannot be methyl when M is hydrogen; 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.

Dependencies are inferred from the claim text.