129822-39-5Relevant articles and documents
Synthetic method for Laquinimod intermediate 2-amino-6-chlorobenzoic acid
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Paragraph 0022; 0029-0031; 0038-0040; 0047-0049, (2019/10/01)
The invention discloses a synthetic method for a Laquinimod intermediate 2-amino-6-chlorobenzoic acid. The synthetic method is characterized in that the 2-amino-6-chlorobenzoic acid can be obtained through the reaction of 3-chloro-2-methylaniline under the action of a protective agent and an oxidizing agent; and a reaction process includes the following steps: 1) uniformly mixing the 3-chloro-2-methylaniline, the protective agent and a solvent S1, performing stirring reaction for 1-2 h under 40-50 DEG C, and obtaining a mixture I at the end; 2) uniformly mixing the oxidizing agent, water and asolvent S2, introducing a protection gas, controlling a reaction temperature to be 145-155 DEG C and reaction pressure to be 5-7 atmospheric pressure so that a mixture II can be obtained, dropping the mixture I into the mixture II, controlling dropping time to be 50-70 min, then controlling the temperature to be 160-175 DEG C and the reaction pressure to be 8-10 atmospheric pressure, performing continuous reaction for 6-8 h, and obtaining a mixture III after cooling; 3) adding hydrochloric acid and a solvent S3 into the mixture III, controlling the reaction temperature to be 75-90 DEG C and the reaction pressure to be normal pressure, performing reaction for 0.5-1 h, and obtaining a mixture IV after cooling; and 4) adding a solvent S4 into the mixture IV, performing standing and layering,and concentrating, steaming and removing the solvents to obtain a product after an organic phase is washed by water and dried by a drying agent. The method is low in raw material cost and high in yield.
