Hydrochloric Acid → 4-Acetyl-2-fluorobenzene-1-sulfonamide

To a solution of 4-acetyl-2-fluoroaniline (5.0 g, 32.6 mmol, Krueger, G et al., Arzneim Forsch, 34, 11a, 1612 (1984)) in conc-HCl (24.0 mL), sodium nitrate (2.9 g, 42.4 mmol) in water (10 mL) was added at 0° C. After stirring for 1 h, the resultant yellow solution was added slowly to the suspension of copper (II) chloride dihydrate (1.7 g, 9.8 mmol) and sulfur dioxide (10 g, 156 mmol) in acetic acid (25 mL) at 0° C. The mixture was stirred for 30 min at 0° C. and poured into ice water (200 mL) and extracted with CH2Cl2 (80 mL×2). The extracts was cooled to 0°0 C. and 25% aqueous ammonia (70 mL) was added slowly and stirred for 1 h at room temperature. The mixture was concentrated and the residual solid was suspended with ether and collectted by filteration to give the title compound (3.3 g, 46%).

1. stirringThe mixture was stirred for 30 min at 0° C.
2. extractionextracted with CH2Cl2 (80 mL×2)
3. temperatureThe extracts was cooled to 0°0 C
4. additionand 25% aqueous ammonia (70 mL) was added slowly
5. stirringstirred for 1 h at room temperature
6. concentrationThe mixture was concentrated

ORD record

ord-d25eb92e784145a1937ff17551df66f6

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06608095B2