| abstract |
The present invention provides an industrially cheap and effective method for preparing levosalbutamol. This method adopts the 4-hydroxyl-3-hydroxymethyl acetophenone of protection as raw material, reacts with bromine to generate the 4-hydroxyl-3-hydroxymethyl bromoacetophenone of acyl group or alkyl protection, and in (1R ,2S)-(+)-indenol as a catalyst, use borane to perform chiral reduction on the carbonyl group in the above structural formula to obtain 4-hydroxy-3-hydroxymethyl α protected by an acyl group or an alkyl group in R configuration Bromophenylethanol reacts with tert-butylamine to generate acyl or alkyl protected 4-hydroxy-3-hydroxymethylphenylaminoethanol, and finally removes the acyl protecting group to obtain levosalbutamol free base, which can form a salt with acid , the optical purity of the finished product reaches 99.9%, and no other chiral separation methods are required for purification. |