The invention provides a preparation method and intermediates of alasset
hydrochloride, which comprises the following steps: reacting an initial
raw material as shown in a formula 1, which is protected by bare phenolic hydroxyl groups or different protecting groups, with bis (pinacolato) diboron to obtain an intermediate as shown in a formula 2, carrying out
coupling reaction on the intermediate and a compound as shown in a formula 3 to obtain a corresponding hydroxyl-protected intermediate as shown in a formula 4, and separating and purifying the intermediate to obtain the alasset
hydrochloride. The preparation method comprises the following steps: carrying out catalyst pressurized hydrogenation, carrying out asymmetric chiral hydrogenation to obtain an intermediate as shown in a formula 5, carrying out substitution or
reductive amination to obtain an intermediate as shown in a formula 6, carrying out
nucleophilic substitution on the intermediate as shown in a formula 7 to obtain an intermediate as shown in a formula 8, and carrying out deprotection to obtain a target product as shown in a formula I. According to the invention, a
chiral resolution link in the existing preparation technology is avoided, and a chiral group is introduced through
asymmetric hydrogenation, so that the yield is greatly improved, the production cost is greatly reduced, the tedious and tedious synthesis steps in the original process are shortened, and the post-treatment is simpler and more controllable.