Bromine → 3-bromo-4H,5H,6H-pyrrolo[1,2-b]pyrazole

Participants

Reaction Steps

Bromine (22.4 mL, 435 mmol) was added to a solution of 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole 8 (47.2 g, 437 mmol) and NaOAc (36.2 g, 440 mmol) in AcOH (750 mL) drop wise at 0° C. The mixture was stirred at the same temperature for 10 minutes then neutralized by the addition of aqueous sodium bicarbonate. The aqueous layer was extracted with EtOAc (5×200 mL) and the organic extracts were dried over magnesium sulfate and concentrated under reduced pressure to afford 3-bromo-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole (73.5 g).

Provenance & Evidence