40161-55-5

Colorless liquid

2-Bromo-5-fluorobenzotrifluoride is an organofluorobenzene compound mainly used as an organic reagent and pharmaceutical intermediate, and can be used as a starting material for the preparation of HSD-016.  HSD-016 inhibits 11β-hydroxysteroid dehydrogenase (11β-HSD1) to convert cortisone into cortisol for the development of drugs for the treatment of type 2 diabetes.

The 1L stainless steel reactor was cooled to -10 °C and then 450 g of anhydrous hydrofluoric acid and 6.0 g of anhydrous potassium fluoride were added to the reactor. Subsequently, 248 g of 5-amino-2-bromobenzotrifluoride was added and 75.5 g of sodium nitrite was added slowly, ensuring that the temperature of the reaction system did not exceed 5 °C. Stirring was done for 30 minutes to complete the diazotization reaction. The temperature of the reaction system was raised to 60°C and maintained, at which time the fluorinated diazonium salt began to decompose slowly and release gases, which were absorbed by the base after passing through the cooling buffer. After the reaction is complete and no more gas is released, the excess hydrofluoric acid in the reactor is recovered and the mixture is cooled to 0°C. A 10% KOH solution was added to the reactor to neutral and steam distillation was carried out to obtain 233 g of crude 2-bromo-5-fluorobenzotrifluoride. The distillation was carried out by filling a distillation column and the 110°C-120°C fractions were collected at a pressure of 40 mmHg to obtain 209 g of a colorless transparent liquid, 2-bromo-5-fluorobenzotrifluoride, with a GC purity of 99% and a yield of 86.8%.

[1] Patent: CN106905104, 2017, A. Location in patent: Paragraph 0020; 0023
[2] Patent: CN104447183, 2016, B. Location in patent: Paragraph 0112-0134
[3] Patent: WO2016/63300, 2016, A1. Location in patent: Page/Page column 9