The present invention provides a process for preparing a compound of formula (VI) or a salt thereof, the process comprising: (i) reacting 4-methoxyphenyl acetone with an amine of formula (VIII) under conditions of reductive amination to produce a compound of formula (II) or a salt thereof, wherein there is no isolation of an imine intermediate formed during the reductive amination; (ii) condensing the compound (II) or the acid addition salt thereof with an α-haloketone of formula (III) to produce the compound of formula (IV); (iii) reducing the compound (IV) to a compound of formula (V); and (iv) reducing the compound (V) to the compound of formula (VI), wherein the reduction is carried out in the presence of either (1) a hydrogen donating compound in the presence of a hydrogen transfer catalyst; or (2) ammonium formate using a hydrogenation catalyst, wherein R
1
and R
2
are independently optionally substituted arylalkyl, and Hal is selected from chloro or bromo.
本发明提供了一种制备公式(VI)化合物或其盐的过程,该过程包括:(i)在还原胺化的条件下,将4-
甲氧基苯乙酮与公式(VIII)胺反应,以产生公式(II)化合物或其盐,其中在还原胺化过程中没有分离出
亚胺中间体;(ii)将化合物(II)或其酸加成盐与公式(III)的α-卤代酮缩合,以产生公式(IV)化合物;(iii)将化合物(IV)还原为公式(V)化合物;(iv)将化合物(V)还原为公式(VI)化合物,其中还原是在(1)氢转移催化剂存在下的氢供体化合物的存在下进行;或(2)使用氢化催化剂的
甲酸铵,其中R1和R2分别是可选的取代芳基烷基,Hal选自
氯或
溴。