Water → 5-BROMO-2,3-DIMETHYLPYRIDINE

To a stirred solution of 2,3-dimethyl-pyridine (6.79 mL, 60 mmol) in fuming sulfuric acid (80 mL) held at 150° C. in a round bottom flask fitted with a water cooled reflux condenser and a calcium chloride filled drying tube, was added, dropwise, bromine (3.1 mL, 60 mmol) over 2 hr. The resulting dark red solution was stirred for 16 hr then cooled to room temperature and allowed to stand overnight. This mixture was poured into approximately 400 g of ice. This mixture was brought to pH 12 with cooling in an ice bath. The resulting mixture was extracted with ether and the ether extract washed with brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica chromatography (50 g silica, eluted with 2-20% ethyl acetate in hexanes) to give the title compound (8.3 g) as a colorless oil.

1. temperaturecooled
2. temperaturereflux condenser
3. customdrying tube
4. additionwas added
5. waitto stand overnight
6. temperaturewith cooling in an ice bath
7. extractionThe resulting mixture was extracted with ether
8. extractionthe ether extract
9. washwashed with brine
10. dry with materialdried over magnesium sulfate
11. concentrationconcentrated under reduced pressure
12. customThe residue was purified by silica chromatography (50 g silica, eluted with 2-20% ethyl acetate in hexanes)

ORD record

ord-d77d45689a05457daaba133ec4156a6d

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09040504B2