Acetic Acid → 5-broMo-2-chloropyridine-3-sulfonyl chloride

To a solution of 3-amino-5-bromo-2-chloropyridine (0.23 g, 1.1 mmol) in acetonitrile (3.0 mL) at −15° C. was added a solution of sodium nitrite (0.091 g, 1.3 mmol) in water (1.20 mL), followed by the addition of concentrate hydrochloric acid (1.8 mL, 21.3 mmol) and the reaction mixture was stirred for 5 minutes. A 30 wt % solution of sulfur dioxide in acetic acid 3.0 mL, 1.3 mmol) was prepared and introduced into the reaction mixture, followed by the addition of a solution of copper(II) chloride 0.091 g, 0.68 mmol) in water (1.2 mL). The stirring was continued for an additional 3 hours at −5° C. The pH of the mixture was adjusted to 8 by the addition of a solution of potassium hydrogenphosphate and 2M aqueous sodium hydroxide and partitioned with ethyl acetate (50 mL). The organic layer was separated and washed with water (10 mL) and brine (10 mL), dried over sodium sulfate, filtered and concentrated to give 5-bromo-2-chloropyridine-3-sulfonyl chloride (0.20 g, 63%).

1. additionintroduced into the reaction mixture
2. waitThe stirring was continued for an additional 3 hours at −5° C
3. custompartitioned with ethyl acetate (50 mL)
4. customThe organic layer was separated
5. washwashed with water (10 mL) and brine (10 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-fb42b1f198ed4617b29f50a553032302

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08648066B2