Hydrofluoric Acid → 5-Amino-2-fluorobenzonitrile

Participants

Reaction Conditions

Reaction Steps

A 50 ml. ether and hexane solution of 9.8g. of 3-cyanophenylazide prepared in Step A above was charged to a rocker bomb and the ether and hexane were blown down under nitrogen. Then, 100 ml. of hexane was introduced, followed by 20 ml. of concentrated hydrogen fluoride, after which the bomb was shaken at room temperature for 10 hours. The reaction mixture was cooled, vented, and poured from the bomb, and the bomb rinsed with 40 ml. of water and 40 ml. of dichloromethane. The combined hexane, dichloromethane, and hydrogen fluoride were blown down under nitrogen. The resulting residue was combined with the aqueous rinse, cooled to 0° C., and rendered alkaline with KHCO3. The residue was then extracted three times with 75 ml. of dichloromethane per extraction, and the combined extracts dried over MgSO4 and then concentrated under reduced pressure to yield 6.5g. of a brown solid. This product was then recrystallized from boiling cyclohexane to yield 5.8g. (53%) of product with a m.p. of 88°-89° C. whose structure was confirmed by IR.

Provenance & Evidence