This invention relates to certain esters and/or ethers of known .beta..sub.2 -agonists, which esters and/or ethers possess favorable properties for the treatment of asthma and all types of chronic obstructionary pulmonary diseases (COPD).
.beta..sub.2 -agonists are well known in the art, e.g. albuterol which is described in U.S. Pat. No. 3,644,353. Certain esters of albuterol or compounds closely related to albuterol have also been described, e.g. in U.S. Pat. No. Re. 30,241, British Patent No. 1,298,771, U.S. Pat. No. 3,904,671. However, none of these publications describe or suggest the ester and/or ethers of this invention.