Bromine → 7-bromo-1H,2H,3H-pyrazolo(1,5-a)imidazole hydrobromide

Participants

Reaction Steps

A 100-mL round-bottom flask was charged with 2,3-dihydro-1H-imidazo[1,2-b]pyrazole (1.7 g, 15.6 mmol) and acetic acid (5 mL). A solution of bromine (7.39 g, 46.2 mmol) in acetic acid (47 mL) was then added slowly. The resulting solution stirred for 3 h at room temperature. The reaction mixture was filtered and the filtrate was concentrated under vacuum to afford 7-bromo-2,3-dihydro-1H-imidazo[1,2-b]pyrazole hydrobromide (3.0 g, 72%) as a yellow solid. MS (ESI, pos. ion) m/z 188, 190 [M+H]+.

Provenance & Evidence