Iodoethane → 2-Bromo-5-(ethylsulfonyl)benzoic acid

Participants

Reaction Steps

To 2-bromo-5-(chlorosulfonyl)benzoic acid (Preparation 72, 10.1 g, 33.8 mmol) dissolved in THF (100 mL) was added hydrazine monohydrate (3.32 mL, 67.6 mmol) cautiously at 0° C. under nitrogen. A fine precipitate formed, the reaction was allowed to warm to room temperature over 126 hours before filtering. The solid was washed with heptanes, dried under reduced pressure and dissolved in industrial methylated spirit (100 mL). To this solution was added sodium acetate (16.6 g, 203 mmol) and ethyl iodide (13.5 mL, 169 mmol) and the reaction heated to reflux for 20 hours. After cooling to room temperature, the solvent was removed under reduced pressure and the residue partitioned between EtOAc (500 mL) and sodium hydroxide solution (1M, 500 mL). The layers were separated and the organic layer discarded. The aqueous layer was acidified to pH=1 with HCl (1M, 500 mL) and extracted with EtOAc (5×500 mL). The combined organic layers were dried over MgSO4 and the solvent removed under reduced pressure to give the title compound as a tan solid in 48% yield, 4.82 g.

Provenance & Evidence