Hydrochloric Acid → 3-Bromo-4-fluorobenzene-1-sulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

Concentrated HCl (1.93 mL, 23.16 mmol) was added to a solution of 3-bromo-4-fluoro-phenylamine ((Example 265: part a) 2.2 g, 11.58 mmol) in 18 mL of 2:1 DCM/MeOH. A precipitate appeared and another 9 mL of 2:1 DCM/MeOH was added. The solution was cooled to −5° C. and tert-butylnitrate (2.71 mL, 23.16 mmol) was added dropwise over 8 min. After stirring for 15 min, sulfur dioxide (˜5 mL) was condensed into the reaction, followed by addition of copper (II) chloride (592 mg, 3.47 mmol) (gas evolution). The solvent was removed in vacuo and the residue was purified by SiO2 flash column chromatography to yield the title compound (1.9 g, 59%). 1H-NMR (CDCl3): δ 8.31 (dd, 1H, J=2.3, 5.8 Hz), 8.04 (ddd, 1H, J=2.6, 4.1, 8.8 Hz), 7.39 (dd, 1H, J=7.7, 8.8 Hz).

Provenance & Evidence