Yield:115029-22-6 90.4%

Reaction Conditions:

Stage #1:1-fluoro-2-trifluoromethylbenzene with lithium diisopropyl amide in tetrahydrofuran at -80; for 0.666667 h;Inert atmosphere;
Stage #2:carbon dioxide in tetrahydrofuran for 2 h;Inert atmosphere;
Stage #3: with hydrogenchloride in water;ethyl acetateTemperature;

Steps:

1.1.a; 2.1.a (1) Synthesis of compound C:
a. Under nitrogen atmosphere, take 1.5g compound A and 15mL tetrahydrofuran into the reactor in turn, control the temperature to -80, dropwise add 10mL tetrahydrofuran solution containing 1.2g diisopropylamine lithium, maintain the temperature at -80, Continue to stir for 40 minutes, and feed carbon dioxide into the reactor. Use carbon dioxide to maintain the standard atmospheric pressure in the reactor. Stir for 2h. Then add 15mL of dilute hydrochloric acid and 30mL of ethyl acetate to the reactor. Concentrate to obtain 1.72g of compound B, namely 2-fluoro-3-benzotrifluorotoluic acid, with a yield of 90.4% and a purity of 98.8%.

References:

CN112624911, 2021, A Location in patent:Paragraph 0018-0019; 0030-0031

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