Trifluoroacetic acid → 4-Amino-3-fluorobenzonitrile

Temperature

0 °C

Trifluoroacetic acid (1 ml) was added dropwise to a solution of 3-fluoro-4-[(4-methoxybenzyl)amino]benzonitrile (1.0 g, 3.9 mmol), obtained in Example 25(1), in anhydrous dichloromethane (20 ml) cooled to 0° C. with stirring. The resulting mixture was stirred at room temperature overnight. At the end of this time, the reaction mixture was poured into saturated aqueous sodium hydrogencarbonate solution at 0° C. The resulting mixture was partitioned between ethyl acetate and water. The organic layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residual oil was chromatographed on a silica gel column using ethyl acetate-hexane (1:6) as the eluant to afford 4-amino-3-fluorobenzonitrile (252 mg, yield 47%) as a pale orange solid which was recrystallized from ethyl acetate-hexane to give white powdery crystals. Melting point: 84° C.

1. stirringThe resulting mixture was stirred at room temperature overnight
2. customThe resulting mixture was partitioned between ethyl acetate and water
3. washThe organic layer was washed with saturated aqueous sodium chloride solution
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residual oil was chromatographed on a silica gel column

ORD record

ord-d65161b1b29d4a619582d000ecb4f2fd

Source dataset

uspto-grants-2003_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06653330B2