Bromine → 3-Bromo-5-chloropyridin-2-amine

Temperature

45 °C

A suspension of 2-amino-5-chloropyridine (5.14 g, 40 mmol) and anhydrous sodium acetate (3.29 g, 40 mmol) in acetic acid (25 mL) was mechanically stirred and warmed to a bath temperature of 45° C. A solution of bromine (2.1 mL, 40 mmol) in acetic acid (2 mL) was added over 1 hour. The resulting orange mixture was cooled to 15° C. and filtered. The solids were taken up in 400 mL of water, the suspension made basic by addition of 1 N NaOH and the suspension extracted with ethyl acetate (5×100 mL). The combined extracts were washed with 10% NaHSO3 (1×100 mL) and were dried over MgSO4. Concentration afforded 2-amino-3-bromo-5-chloropyridine (4 g, 48), mp 82-84° C.

1. temperatureThe resulting orange mixture was cooled to 15° C.
2. filtrationfiltered
3. additionthe suspension made basic by addition of 1 N NaOH
4. extractionthe suspension extracted with ethyl acetate (5×100 mL)
5. washThe combined extracts were washed with 10% NaHSO3 (1×100 mL)
6. dry with materialwere dried over MgSO4
7. concentrationConcentration

ORD record

ord-490f70234edd41dfb87b56b236f4b919

Source dataset

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06916933B2