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

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.

1. customA fine precipitate formed
2. filtrationbefore filtering
3. washThe solid was washed with heptanes
4. customdried under reduced pressure
5. dissolutiondissolved in industrial methylated spirit (100 mL)
6. temperaturethe reaction heated
7. temperatureto reflux for 20 hours
8. temperatureAfter cooling to room temperature
9. customthe solvent was removed under reduced pressure
10. customthe residue partitioned between EtOAc (500 mL) and sodium hydroxide solution (1M, 500 mL)
11. customThe layers were separated
12. extractionextracted with EtOAc (5×500 mL)
13. dry with materialThe combined organic layers were dried over MgSO4
14. customthe solvent removed under reduced pressure

ORD record

ord-bcd78ff97796488482650220001d45a2

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952008B2