Synthesis
The synthesis of 2-Amino-3-chlorobenzoic acid is as follows:
70 ml of methanol was added to an autoclave, and cooled to -70° C., and 16 g (942 mmol) of a generated ammonia gas was added. 30 g (157 mmol) of 2,3-dichlorobenzoic acid and 0.78 g (7.85 mmol) of copper(I) chloride were added. The autoclave was sealed, and heated in an oil bath at 130° C. and 30 atmospheres for 20 hours. After the completion of the reaction, the autoclave was cooled to room temperature, and the reaction mixture was transferred into a reaction flask. 100 ml of water was added to the reaction solution, and the reaction solution was heated in an oil bath to 100° C. to remove the ammonia and the methanol. Then, the reaction solution was cooled to room temperature, and hydrochloric acid was added to adjust the pH value to 3. The precipitated crystals were filtered and dried to obtain 21.8 g of 2-amino-3-chlorobenzoic acid as white crystals with a yield of 81%.
