The invention discloses a method for preparing an anti-asthmatic medicament of
salmeterol. The method comprises the following steps of: adding paraxylene, parahydroxyphenylacrylic acid,
formaldehyde and acid medium into a reactor, heating, cooling, filtering, washing and
drying to obtain 3-
hydroxymethyl-4-hydroxyl-phenylacrylic acid; adding the 3-
hydroxymethyl-4-hydroxyl-phenylacrylic acid into the reactor, then adding oxyful,
lipase and
ethyl acetate to finally obtain 3-
hydroxymethyl-4-hydroxyl-(beta-hydroxy)-phenylpropyl
aldehyde, adding the 3-hydroxymethyl-4-hydroxyl-(beta-hydroxy)-phenylpropyl
aldehyde and 6-(4-phenylbutoxy)
hexylamine into the reactor, heating for reflowing, cooling, filtering, adding
sodium borohydride in batches into filtrate, stirring at normal temperature, then evaporating to
dryness, extracting, combining organic
layers,
drying, filtering and evaporating to
dryness to obtain a
solid, and separating by using the
column chromatography to obtain the final product. The invention has novel and short synthetic
route, convenient experiment operation, higher yield of the target product and lower production cost.