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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence