461-97-2

108-69-0

461-97-2

The general procedure for the synthesis of 3,5-dimethylfluorobenzene from 1-amino-3,5-xylene is as follows: 1. Continuous diazotization step: - Preparatory material A: 1-amino-3,5-xylene (100 mmol), fluoboric acid (120 mmol) and hydrochloric acid (180 mmol) were dissolved in 50 mL of water. - Prepare Material B: Dissolve sodium nitrite (105 mmol) in 50 mL of water. - Material A and Material B were each pumped through a T-fitting into a reaction tube at a flow rate of 4 mL/min at 25 °C. The mixture flowed through the outlet and was collected in a cooling vessel. Vigorous stirring was maintained. - The reaction mixture was cooled to -5 °C and the solid was collected by filtration. The solid was washed with methanol and subsequently dried under vacuum to give diazonium tetrafluoroborate. 2. Continuous fluorination step: - The diazonium tetrafluoroborate prepared above was suspended in 300 mL of co-solvent and introduced continuously into the reaction tube at a flow rate of 4 mL/min. - The reaction was maintained at the set temperature for 1 min, followed by cooling in the tandem tube. - The reaction solution was collected and washed with aqueous NaOH and water to give an almost colorless liquid of 3,5-dimethylfluorobenzene.