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

Temperature

0 °C

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° 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. addition25% aqueous ammonia (70 mL) was added slowly
4. stirringstirred for 1 h at room temperature
5. concentrationThe mixture was concentrated

ORD record

ord-38ef4584ee1c4d61886c70f6a6caef11

Source dataset

uspto-grants-2004_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06727238B2