An imidazo [1,2-b]pyridazine compound of the formula (I):
wherein R₁ is a halogen atom or a lower alkyl group optionally having substituent(s), R₂ and R₃ are, independently, a hydrogen atom, a lower alkyl group optionally having substituent(s), a cycloalkyl group or a phenyl group optionally having substituent(s) or R₂ and R₃ together with the adjacent nitrogen atom to which they bond may form a heterocyclic ring optionally having substituent(s), X is an oxygen atom or S(O)k (k is zero to two), a group
is a bivalent three to seven membered homocyclic or heterocyclic group optionally having substituent(s), m¹ and m² each is an integer of 0 to 4 and n is an integer of 0 or 1; or its salt, which is useful as antiasthmatics..
式 (I) 的
咪唑并[1,2-b]
哒嗪化合物:
其中 R₁ 是卤素原子或任选具有取代基的低级烷基,R₂ 和 R₃ 独立地是氢原子、任选具有取代基的低级烷基、环烷基或任选具有取代基的苯基,或 R₂ 和 R₃ 独立地是氢原子、任选具有取代基的低级烷基、环烷基或任选具有取代基的苯基、环烷基或任选具有取代基的苯基,或 R₂ 和 R₃ 与它们键合的相邻氮原子可形成任选具有取代基的杂环。
是二价三至七成员的同环或杂环基团,可选择具有取代基,m¹ 和 m² 均为 0 至 4 的整数,n 为 0 或 1 的整数;或其盐,可用作抗哮喘药。