Sodium Hydroxide → 2-Amino-4'-fluorobenzophenone

30 g of 2-amino-4′-fluorobenzophenone methanesulfonate was added to 150 g of o-dichlorobenzene, the resulting mixture was heated at 80° C. Then, the reaction solution was made alkaline with 25% aqueous solution of sodium hydroxide. The reaction solution was separated into phases at the same temperature and washed with 5% brine solution. The organic phase was dried over anhydrous magnesium sulfate, and filtered at 80° C. The filtrate was gradually cooled, stirred at 0 to 5° C. for 4 hours, filtered and washed with a small amount of toluene. After drying, 19 g of 2-amino-4′-fluorobenzophenone was obtained.