Bromine → 3-Bromo-2-(propan-2-yl)pyrazolo[1,5-a]pyridine

Participants

Reaction Steps

To a solution of 50 g of 2-isopropylpyrazolo[1,5-a]pyridine in 300 ml of chloroform were added about 20 ml of bromine until the solution became faintly yellow under stirring and cooling to 5°-15° C. After the addition was completed, the mixture was stirred at room temperature for 30 minutes, then poured into aqueous 10% sodium bisulfite solution and extracted with chloroform. The chloroform layer was washed with aqueous 10% sodium hydroxide and then water, dried over anhydrous sodium sulfate, and concentrated in vacuo to give 75 g of crude 2-isopropyl-3-bromopyrazolo[1,5-a]pyridine, as colorless needles, mp 51°-52° C.

Provenance & Evidence