sodium 3-fluorobenzenesulfinate synthesis

Yield:935447-39-5 98%

Reaction Conditions:

with sodium carbonate;sodium sulfite in water at 50; for 2 h;

Steps:

Exemplified by the synthesis of sodium 3-fluorobenzenesulfinate (6.2)

A solution of sodium sulfite (2.84 g, 22.5 mmol) in H₂0 (30 mL) was stirred at room temperature for 10 minutes. Base, such as sodium carbonate (3.18 g, 30.0 mmol), was added to the stirred solution. The resulting solution was stirred at elevated temperature, such as 50°C for 10 minutes. 3-Fluorobenzenesulfonyl chloride 5.2 (2.0 mL, 15.0 mmol) was added dropwise to the solution and was stirred at 50°C for 2 hours. The reaction mixture was evaporated to dryness and re-dissolved in EtOH (50 mL). The suspension was stirred at room temperature for 20 minutes. The suspension was filtered and the filtrate evaporated to afford a white solid, which was stirred with MeCN (20 mL) and then filtered to afford sodium 3-fluorobenzenesulfinate 6.2 (2.68 g, 98%) as a white solid. NMR (400 MHz, DMSO-d₆) δ: 7.36 (m, 1 H), 7.29 (m, 1 H), 7.21 (m, 1 H) and 7.03 (m, 1 H).

References:

WO2018/65611,2018,A1 Location in patent:Page/Page column 75; 89