Sulfur Dioxide → 4-broMo-2-cyanobenzene-1-sulfonyl chloride

Temperature

0 °C

To a solution of 5-amino-2-bromo benzonitrile (10.0 g, 50.75 mmol) in concentrated hydrogen chloride (25 mL) and acetic acid (25 mL) was added sodium nitrite (3.85 g, 55.82 mmol) in water (12.5 mL). The reaction was stirred at 0° C. for 15 minutes. In a separate flask was prepared a saturated solution of sulfur dioxide in acetic acid (25 mL) at 0° C. Calcium chloride dihydrate (3.46 g, 20.30 mmol) was added to the saturated solution prior to the dropwise addition of the solution containing 5-amino-2-bromo benzonitrile. The reaction mixture was warmed to room temperature and stirred for 16 hours. The reaction mixture was diluted with water and the resulting white precipitate collected by filtration. The solids were dissolved in dichloromethane and washed with a saturated aqueous solution of sodium chloride. The organics were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The material was purified by column chromatography (5% ethyl acetate in heptane elution). Fractions containing product were combined and concentrated in vacuo to obtain the title compound as a colourless solid.

1. additionto the dropwise addition of the solution
2. temperatureThe reaction mixture was warmed to room temperature
3. stirringstirred for 16 hours
4. filtrationthe resulting white precipitate collected by filtration
5. dissolutionThe solids were dissolved in dichloromethane
6. washwashed with a saturated aqueous solution of sodium chloride
7. dry with materialThe organics were dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe material was purified by column chromatography (5% ethyl acetate in heptane elution)
11. additionFractions containing product
12. concentrationconcentrated in vacuo

ORD record

ord-10e56a79ba7f45cd9e4c08431d3b4042

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09096558B2