Compounds of the formula I ##STR1## in which X.sup.1 and X.sup.2 the same or different, signify hydrogen, a C.sub.1 - to C.sub.6 -alkyl radical or a halogen atom or, insofar as they stand in neighbouring positions, together with the carbon atoms carrying them, form a condensed-on phenyl ring, and R signifies a possibly substituted carbocyclic or heterocyclic saturated or unsaturated radical, as well as their physiologically compatible salts, processes for their preparation, as well as medicaments which contain these compounds for the treatment of allergic diseases.