A process for producing a brominated acetal (represented by the formula 3) includes (a) brominating a trifluoromethyl-substituted acetophenone by Br2 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
溴代
缩醛(
化学式3)的过程包括:(a)在烷基二醇存在下,用Br2对三
氟甲基取代的
乙酰苯甲酮进行
溴化。可以通过以下步骤制备三
氟甲基取代的2-烷氧基
乙酰苯甲酮衍
生物(
化学式9):(b)将
溴代
缩醛与
金属烷氧化物反应,将
溴代
缩醛转化为醚;(c)在酸催化剂存在下
水解醚,从而从醚中去除
缩醛基,从而制备2-烷氧基
乙酰苯甲酮衍
生物。或者,可以通过以下步骤制备2-烷氧基
乙酰苯甲酮:(a)将三
氟甲基取代的苯甲
酰卤与
缩醛化试剂反应,将苯甲
酰卤转化为
缩醛;(b)将
缩醛与
金属烷氧化物反应,将
缩醛转化为醚;(c)在酸催化剂存在下
水解醚,从而从醚中去除
缩醛基。