Phosphorus oxychloride → Pyridine-3-sulfonyl chloride

Temperature

120 °C

A mixture of pyridine-3-sulfonic acid (3 g, 18.8 mmol), phosphorus pentachloride (6.04 g, 29.0 mmol) and phosphorus oxychloride (15 mL) was heated at 120° C. overnight. Excess phosphorus oxychloride was evaporated under reduced pressure, the residue quenched with ice and partitioned between water and diethyl ether. The pH of the aqueous phase was adjusted by addition of solid sodium bicarbonate to pH 7-8, then the organic layer was separated and washed successively with sat. sodium bicarbonate solution, water and brine. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give a residue which was dried under high vacuum to afford pyridine-3-sulfonyl chloride (2.83 g, 85%) as a solid.

1. customExcess phosphorus oxychloride was evaporated under reduced pressure
2. customthe residue quenched with ice
3. custompartitioned between water and diethyl ether
4. additionThe pH of the aqueous phase was adjusted by addition of solid sodium bicarbonate to pH 7-8
5. customthe organic layer was separated
6. washwashed successively with sat. sodium bicarbonate solution, water and brine
7. dry with materialThe organic phase was dried over anhydrous sodium sulfate
8. concentrationconcentrated under reduced pressure
9. customto give a residue which
10. customwas dried under high vacuum

ORD record

ord-04a1dda3a56e467a938241442daa5f07

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08604029B2