Water → 5-chlorothiazolo[5,4-b]pyridin-2-amine

Participants

Reaction Conditions

Reaction Steps

To glacial acetic acid (125 mL) pre-cooled to 5° C. were added potassium thiocyanate (93 g, 961 mmol) and 6-chloropyridin-3-amine (Q-1) (15 g, 117 mmol). The mixture was placed in a freezing mixture of ice and salt and stirred, while 10 mL of bromine in glacial acetic acid (30 mL) was added from an addition funnel at such a rate that the temperature never rose beyond 0° C. After all the bromine had been added, the solution was stirred for an additional 2 h at 0° C. and at room temperature overnight. Water (60 mL) was added quickly, and the slurry maintained at 90° C. was filtered hot. The orange filter cake was placed in the reaction flask. Glacial acetic acid (60 mL) was added to the flask. The mixture in the flask was maintained at 85° C. was filtered hot once again. The combined filtrates were cooled and neutralized with concentrated ammonia solution to pH 6. A precipitate was collected as the title compound (19 g). MS (m/z): 186 (M+1)+.

Provenance & Evidence