Oblon, Fisher, Spivak, McClelland & Maier
Antiallergic methods
 Compounds of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are each hydrogen or methyl, providing that when R.sub.1 is hydrogen, R.sub.2 is hydrogen, have been found to be useful in relieving allergic symptoms by inhibiting histamine-release from mast cells. They can be used in free form or in the form of pharmaceutically acceptable acid addition salts. 
Fujisawa Pharmaceutical Co., Ltd.
A A
A61K A61P
inventional inventional
Hideaki Nobuo Hiroyuki
Shiokawa Kawaguchi Kikuchi