Preparation
9.3 g (0.05 mol) of 2-bromo-6-aminotoluene and 43.6 g (0.20 mol) of 40% HBF4 solution were added to a 150 mL four-necked flask. The reaction was carried out at 25 °C for 1 h, then cooled to -5 °C in an ice-salt bath. 11.5 g (0.055 mol) of 33% NaNO2 solution was added dropwise, and the mixture was stirred at -5 °C for another 1 h. The mixture was filtered, washed with anhydrous ethanol (30 mL × 2), and dried under vacuum to obtain 13.9 g of diazonium fluoroborate. In a dry 250 mL four-necked flask, 50 mL of petroleum ether was added and heated to 70 °C. The dried diazonium fluoroborate was added in portions, producing a large amount of fumes. These fumes were absorbed with 10% NaOH solution until no more fumes were produced, at which point the reaction was stopped. Steam distillation yielded 6.5 g of 2-bromo-6-fluorotoluene with a purity of 99.3% (GC) and a yield of 68.5%.
Uses
2-Bromo-6-fluorotoluene is a toluene derivative, its structure contains bromine and fluorine atom active groups, so it has a high chemical reactivity and easily substitution and fluorination reaction with other compounds. It is mainly used as raw material or intermediate of organic synthesis.
