The invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R
1
is H, chlorine, or bromine; R
2
is electron attractive groups selected from the group consisting of CF
3
, CN, fluorine, CH
3
SO
3
, CF
3
SO
3
, and NO
2
; R
3
is linear or branched alkyl having 1 to 10 carbon atoms, linear or branched alkoxyalkyl having 2 to 10 carbon atoms, aliphatic alcohol having 1 to 10 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 &bgr;
2
-receptor agonist and can be used for the treatment of asthma and bronchitis.
1
该发明提供了公式(I)的化合物及其药学上可接受的盐,其中R1为H、
氯或
溴;R2为从
CF3、CN、
氟、CH3SO3、 SO3和
NO2组成的电子吸引基团;R3为具有1至10个碳原子的线性或支链烷基、具有2至10个碳原子的线性或支链烷氧基烷基、具有1至10个碳原子的
脂肪醇或具有3至6个碳原子的环烷基。该发明还涉及制备所述化合物的方法和包含其的组合物。本发明的化合物具有β2受体激动剂的效果,可用于治疗哮喘和支气管炎。