| 摘要 |
A compound of the formula <IMAGE> wherein R1 is a hydrogen atom or a lower alkyl group which may be substituted with hydroxy, lower alkyl or di-lower alkylamino; R2 is a hydrogen atom, an amino group or a lower alkylamino group; and R3 is a lower alkyl group, and a non-toxic salt thereof, and a process for preparing the same are disclosed. The compound and the salts thereof exhibit anti-allergic effects by the two different mechanisms and are expected to be useful as drugs for treating allergic diseases such as asthma, pollen allergy, atopic dermatitis and the like. |
