Hydrochloric Acid → Methyl 4-(chlorosulfonyl)-2-fluorobenzoate

Participants

Reaction Steps

Sodium nitrite (0.54 g, 8.0 mmol) was added portion wise to a stirred solution of methyl 4-amino-2-fluorobenzoate (1.0 g, 6.0 mmol) in acetic acid (7 ml) and HCl (concentrated, 2.5 ml) while maintaining the temperature below 15° C. This solution was then added drop wise to a stirred solution of saturated sulfur dioxide, copper (II) chloride (0.25 g, 1.0 mmol) and water (0.5 ml) in acetic acid (5 ml) at 5° C. The reaction mixture was allowed to warm to room temperature and poured over ice water and stirred for a further 15 minutes. The resulting precipitate was collected by filtration, washed with water and dried overnight in a vacuum oven to give the title compound (1.5 g, 55% yield) as a pale brown solid which was used without further purification.

Provenance & Evidence