Hydrochloric Acid → 4-Fluoro-3-methylbenzene-1-sulfonyl chloride

Temperature

0 °C

4-Fluoro-3-methyl-phenylamine (10 g, 79.9 mmol) was mixed with trifluoroacetic acid (100 mL) in a 250 mL flask. After the mixture was cooled to 0° C., concentrated hydrochloric acid (10 mL) was added slowly, followed by addition of a solution of sodium nitrite (6.95 g, 100.67 mmol) in water (5 mL) dropwise over 20 minutes at 0° C. The mixture was stirred for another 10 minutes, and then poured into a stirred mixture of acetic acid (120 mL), sulfurous acid (0.94 N aqueous sulfur dioxide solution, 120 mL), copper(II) chloride (13.6 g, 79.9 mmol) and copper(I) chloride (100 mg) at 0° C. The resulting mixture was allowed to warm to room temperature and stirred for 15 hours, and then poured into water (200 mL). The aqueous layer was extracted with ethyl acetate (100 mL×3). The combined organic layers were dried over sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography (20% ethyl acetate in petroleum ether) to afford 4-fluoro-3-methyl-benzenesulfonyl chloride (5.2 g, 31.2%) (reference: Cherney, R. J. et al., J. Med. Chem. 46 (2003) 1811). 1H NMR (400 MHz, CDCl3) δ ppm 7.96-7.90 (m, 2 H), 7.284-7.229 (m, 1 H), 2.42 (d, J=1.6 Hz, 3 H).

1. temperatureto warm to room temperature
2. stirringstirred for 15 hours
3. extractionThe aqueous layer was extracted with ethyl acetate (100 mL×3)
4. dry with materialThe combined organic layers were dried over sodium sulfate
5. concentrationconcentrated in vacuo
6. customThe residue was purified by column chromatography (20% ethyl acetate in petroleum ether)

ORD record

ord-1d80e4adc7014003ade958754d663f5a

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08420675B2