Synthesis
To the reaction system was added 25.9 g (0.8 mol) of methanol, and after chlorine-fluorine exchange using HF according to the method of Example 2, 13.8 g (0.053 mol) of 3,5-bis(trifluoromethyl)benzoyl fluoride fraction was obtained, which was added slowly and dropwise to the reaction system over 60 minutes. Subsequently, the reaction mixture was stirred at 40°C for 4 hours. The generation of 14.2 g (0.052 mol) of methyl 3,5-bis(trifluoromethyl)benzoate was confirmed by gas chromatographic analysis (yield: 98%, selectivity: 100%). By vacuum distillation, 13.9 g (0.05 mol) of methyl 3,5-bis(trifluoromethyl)benzoate was isolated (yield: 96%). Examples 17-31 Various (fluoroalkyl)benzene derivatives were prepared with reference to the methods of Examples 2-16. To improve the purity of the product, Example 17 was purified by crystallization twice, and the final distillation step was repeated in the remaining Examples. The purity, residual halogen content and residual metal content of all (fluoroalkyl)benzene derivatives are summarized in Table 2.
