656-64-4

light yellow crystal

3-Bromo-4-fluoroaniline is used in organic synthesis as an intermediate of agrochemicals and active pharmaceutical ingredient.

In a 2L four-necked round-bottomed flask equipped with a stirrer, an Erlenmeyer condenser, a 1L dropping funnel, and a thermometer, 466.9 g (2.07 mol) of tin chloride dihydrate and 760 mL of ethanol were added and the mixture was stirred to room temperature. After the tin chloride was completely dissolved, 102.7 g (0.466 mol) of THF solution of 3-bromo-4-fluoronitrobenzene (760 mL) was slowly added dropwise, followed by continuous stirring for 2 hours at 60 °C. Upon completion of the reaction, the reaction solution was cooled to room temperature and the solvent was removed by distillation under reduced pressure. To the residue, 440 g of ice was added and adjusted to alkaline with 1580 mL of aqueous 7% sodium hydroxide. The slurry formed was separated by filtration and the solid residue was washed with 600 mL of dichloromethane (DCM). The filtrates were combined, the organic layer was separated and the aqueous layer was extracted with 600mL DCM. All DCM layers were combined, washed with 600mL of water and subsequently dried with potassium carbonate. After drying, potassium carbonate was removed by filtration and solvent was removed by distillation under reduced pressure. Finally, the crude product was purified by silica gel column chromatography using toluene as the unfolding agent to give 54.7 g (61.7% yield) of 3-bromo-4-fluoroaniline.

[1] Journal of Organic Chemistry, 1981, vol. 46, # 11, p. 2280 - 2286
[2] Patent: JP2018/90561, 2018, A. Location in patent: Paragraph 0088
[3] Patent: US2004/122237, 2004, A1. Location in patent: Page 369-370
[4] Journal of Medicinal Chemistry, 2012, vol. 55, # 6, p. 2538 - 2548