Pyrazine-2-carboxamide derivatives useful in treating allergic disease

Abstract

Novel pyrazine derivatives useful for treatment of bronchial asthma, allergic gastorenteric trouble, hay fever urticaria, allertic rhinitis, and allergic conjunctivitis, and pharmaceutical compositions thereof, are disclosed. The compounds have the formula I as follows: ##STR1## wherein R represents hydrogen or ##STR2## wherein R.sub.1 and R.sub.2 may be the same or different and each independently represents hydrogen, straight or branched-chain lower-alkyl, or cycloalkyl having three to six carbon atoms inclusive, phenyl which may be substituted with halogen, lower-alkyl, or lower-alkoxy, or wherein R.sub.1 and R.sub.2 together represent alkylene of four to six carbon atoms, inclusive, optionally interrupted by one or two nitrogen atoms or one oxygen atom and said ring being optionally substituted by straight or branched-chain lower-alkyl having one to six carbon atoms inclusive, hydroxy, or phenyl, and pharmaceutically-acceptable salts thereof.