反应详情

4-bromo-2-fluoro-benzylbromide [76283-09-5] is reacted in ethanol with stoichiometric compounds of natrium ethanolate and octylmalonic acid diethylester to form 2-(4-bromo-2-fluoro phenyl)methyl-2-octyl malonic acid diethylester. After usual post-treatment and distillation a 50% aqueous potassium hydroxide solution is added to the methanolic solution and heated until the saponification has ended. After cooling sulfuric acid is added to adjust the pH to a value of 1-2. The 4-fold volume of water is added followed by multiple extraction of methyl-tert.-butylether. The combined organic phases are dried and the solvent is removed under vacuum, finally at 60° C. in the heating bath. The 2-(4-bromo-2-fluoro phenyl)methyl-2-octyl-malonic acid thus obtained after heating for several hours at 150-170° C. is decarboxylated to obtain 3-(4-bromo-2-fluoro phenyl)-2-octyl-propionic acid.