Heterocyclic compounds useful as anti-allergy agents

An anti-allergic compound of the formula ##STR19## wherein:

• the dotted line indicates that the double bond may be in either position;
• R is hydrogen, alkyl, alkenyl, alkoxy, alkenyloxy, aryloxy, aralkoxy, halogen, cyano, nitro, carboxy, hydroxy, formyl, carbalkoxy, hydroxyalkyl, amino, alkylamino, trifluoromethyl, mercapto, trifluoromethoxy, alkylthio, or aminoalkyl, wherein the number of carbon atoms in the alkyl and alkenyl moieties is up to 7 and in the aryl moieties is up to 10;
• Y is N, N--R.sub.2 or CR.sub.2 wherein R.sub.2 is hydrogen, alkyl or aryl and the number of carbon atoms is up to 7 in said alkyl moiety and is up to 10 in the aryl moiety, with the proviso that when Y is NH, (R).sub.a is not hydrogen;
• a is an integer from 1 to 4;
• X and Z are independently O, S, NR.sub.2 or CR.sub.2 wherein R.sub.2 is as defined above, with the proviso that when Y is NR.sub.2, X is not CR.sub.2 ;
• and
• R.sub.1 is hydrogen, alkyl, aryl, acyl, carbalkoxy, or carbaryloxy, wherein the number of carbon atoms in is up to 7 in the alkyl and aliphatic acyl groups and is up to 10 in the aryl and aromatic acyl groups;
• and
• acid addition salts thereof.