Hydrogen Bromide → 2,5-Dibromo-3-methylpyridine

5-Bromo-3-methyl-pyridin-2-ylamine (1.0 eq.) was added portionwise to aqueous HBr (48%; 1.0M). The mixture was stirred 1 h at rt then cooled to −20° C. Bromine (2.8 eq.) was added dropwise followed by a aqueous solution of NaNO2 (1.0M; 2.7 eq.). The final mixture was warmed to rt and stirred for 2 h. The mixture was cooled back to −20° C. then aqueous NaOH (1.0M; 3.0 eq.) was added dropwise over 1 h. The final mixture was warmed to rt and extracted with Et2O (2×). The combined organic extracts were washed with brine, dried over MgSO4, filtered and concentrated to afford the title compound as a yellow solid.

1. temperaturethen cooled to −20° C
2. stirringstirred for 2 h
3. temperatureThe mixture was cooled back to −20° C.
4. extractionextracted with Et2O (2×)
5. washThe combined organic extracts were washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-369110fe8e0b4dd58ad8082fbd9fa3f1

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07153968B2