A process for producing a brominated acetal (represented by the formula 3) includes (a) brominating a trifluoromethyl-substituted acetophenone by Br
2
in the presence of an alkylene diol. It is optional to produce a trifluoromethyl-substituted 2-alkoxyacetophenone derivative (represented by the formula 9) by (b) reacting the brominated acetal with a metal alkoxide, thereby converting the brominated acetal into an ether; and (c) hydrolyzing the ether in the presence of an acid catalyst to remove an acetal group from the ether, thereby producing the 2-alkoxyacetophenone derivative. Alternatively, the 2-alkoxyacetophenone can be produced by (a) reacting a trifluoromethyl-substituted phenacyl halide with an acetalization agent, thereby converting the phenacyl halide into an acetal; (b) reacting the acetal with a metal alkoxide, thereby converting the acetal into an ether; and (c) hydrolyzing the ether in the presence of an acid catalyst to remove the acetal group from the ether.
生产
溴化
缩醛(由式 3 表示)的工艺包括 (a) 用 Br
2
溴化三
氟甲基取代的
苯乙酮。可选择通过以下方法生产三
氟甲基取代的 2-烷
氧基
苯乙酮衍
生物(由式 9 表示):(b) 使
溴化
缩醛与
金属
氧化烷反应,从而将
溴化
缩醛转化为醚;(c) 在酸
催化剂存在下
水解醚,从醚中除去
缩醛基团,从而生产 2-烷
氧基
苯乙酮衍
生物。或者,2-烷
氧基
苯乙酮可以通过以下方法制得:(a) 使三
氟甲基取代的
苯酰卤与
缩醛剂反应,从而将
苯酰卤转化为
缩醛;(b) 使
缩醛与
金属烷
氧基反应,从而将
缩醛转化为醚;(c) 在酸
催化剂存在下
水解醚,以除去醚中的
缩醛基团。