The invention provides compounds of formula (I) having (-) or (+) configuration, or pharmaceutically acceptable salts thereof, wherein R1 is H or halo; R2 is CF3, CN, or halo; R3 is linear or branched alkyl having 1 to 6 carbon atoms, or cycloalkyl having 3 to 6 carbon atoms. The invention also relates to methods for preparing the said compounds and the composition comprising the same. The compounds of the present invention have the effect of β2- receptor agonist and can be used for the treatment of asthma or bronchitis.
本发明提供了具有(-)或(+)构型的式(I)化合物或其药学上可接受的盐,其中 R1 是 H 或卤代物;R2 是
CF3、CN 或卤代物;R3 是具有 1 至 6 个碳原子的直链或支链烷基,或具有 3 至 6 个碳原子的环烷基。本发明还涉及制备上述化合物和包含上述化合物的组合物的方法。本发明的化合物具有β2-受体激动剂的作用,可用于治疗哮喘或支气管炎。