摘要 |
The present invention relates to a novel pyrido[2,3-d]pyrimidine derivative having the formula (I): <IMAGE> (I) wherein each of R1 and R2, which may be the same or different, is a lower alkyl group; and each of R3 and R4, which may be the same or different, is hydrogen, halogen, hydroxy, nitro, amino, hydroxyamino, hydrazino, azido, a lower alkenylamino group or a lower alkylamino group which may optionally have hydroxy; and pharmaceutically acceptable salt thereof. These compounds are useful as anti-allergic agents, for example, for the treatment of bronchial asthma, urticaria, allergic rhinitis, allergic dermatoses or allergic conjunctivitis.
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