Hydrochloric Acid → 5-Amino-2-fluorobenzonitrile

Participants

Reaction Steps

A solution of 74.6 g. of stannous chloride dihydrate, 75 ml. concentrated HCl, and 150 ml. ethanol was cooled in an ice bath and stirred while adding 9.66 g. (0.05 mole) of powdered 2,4-dinitrobenzonitrile at a rate that maintained a temperature of 25°-30° C. The resulting yellow solution was held at 40° C. for 90 minutes while a stream of nitrogen was blown over the surface to evaporate most ot the ethanol. The residue was a yellow slurry, which was cooled in an ice bath and stirred while a solution of 70 g. NaOH in 280 g. of water was added slowly. The mixture was then filtered. The filtrate was extracted four times with ethyl acetate and the extract evaporated to dryness. The residue was combined with the solids from the filtration, and the mixture was extracted with four 150 ml. portions of boiling benzene. The benzene solution was evaporated to dryness to give 4.75 g. of crude product, which was recrystallized from benzene to give 4.67 g. (70% yield) of pure 2,4-diaminobenzonitrile, m.p. 105° C. Anal. Calculated for C7H7N3 : C, 63.19; H, 5.30; N, 31.56. Found: C, 62.54, 62.67; H, 5.24, 5.09; N, 31.32, 31.10.

Provenance & Evidence