Acetic Acid → 5-Methoxy[1,3]thiazolo[5,4-b]pyridin-2-amine

Participants

Reaction Conditions

Reaction Steps

Potassium thiocyanate (156 g, 1600 mmol) is dissolved in acetic acid (1400 mL) and cooled to 0° C. 6-Bromo-pyridin-3-ylamine (50 g, 400 mmol) is dissolved in acetic acid (100 mL) and added dropwise over 10 min. Bromine (25 mL, 480 mmol) is dissolved in acetic acid (100 mL) and added dropwise over 10 min. The reaction is allowed to stir and warm to RT overnight. Acetic acid is removed via concentration. The resulting residue is poured into water (1 L) and adjusted to pH=7 with 1 N sodium hydroxide solution. This is extracted with ethyl acetate. Extracts are combined, washed with brine, and concentrated to a brown sludge. Recrystallization from methanol affords 5-methoxy-thiazolo[5,4-b]pyridin-2-ylamine as a brown solid: 1H NMR (400 MHz, DMSO-D6) δ 3.8 (s, 3 H) 6.7 (d, J=8.8 Hz, 1 H) 7.4 (s, 2 H) 7.6 (d, J=8.6 Hz, 1 H); LC/MS 182.3 (M+1), 180.4 (M−1).

Provenance & Evidence