Compounds of formula (I) ##STR1## wherein X and Y each represent a bond or an alkylene, alkenylene or alkynylene chain; R.sup.1 and R.sup.2 each represent a hydrogen atom or a lower alkyl group; and Py represents a pyridyl group having one or two substituents. The compounds have a stimulant action at beta.sub.2 -adrenoreceptors. The compounds may be used in the treatment of diseases associated with reversible airway obstruction such as asthma and chronic bronchitis.
化合物的公式(I)##STR1## 其中X和Y分别表示键或烷基,烯基或炔基链; R.sup.1和R.sup.2分别表示氢原子或较低的烷基基团; Py表示具有一个或两个取代基的
吡啶基团。这些化合物在beta.sub.2-
肾上腺素受体上具有兴奋作用。这些化合物可用于治疗与可逆性气道阻塞相关的疾病,如哮喘和慢性支气管炎。