反应详情

To a solution of 3 g of 2-isopropylpyrazolo[1,5-a]pyridine in 56 ml of methanol was added 5.74 g of potassium thiocyanate and stirred at room temperature. 3.3 g of bromine was dissolved in 13 ml of methanol saturated with potassium bromide and added dropwise to the previous solution. Then, the mixture was stirred at room temperature for an hour, poured into 130 ml of water and resulting precipitate was filtered and dried. This crude precipitate was recrystallized from methanol to give 3.53 g (yield 87%) of the aimed compound as pale yellow prismatic crystals. mp 91°-92.5° C.

1. additionadded dropwise to the previous solution
2. stirringThen, the mixture was stirred at room temperature for an hour
3. customresulting precipitate
4. filtrationwas filtered
5. customdried
6. customThis crude precipitate was recrystallized from methanol