Hydrochloric Acid → (2-(Trifluoromethyl)imidazo[1,2-a]pyridin-6-yl)boronic acid

Temperature

-20 °C

To a cooled (−78° C.) solution of 6-bromo-2-trifluoromethyl-imidazo[1,2-a]pyridine p (5.66 mmol, 1.50 g) and trimethyl borate (1.2 equiv., 6.79 mmol, 0.706 g) in diethyl ether (7 ml) under N2-atmosphere was added dropwise butyllithium (1.2 equiv., 6.79 mmol, 2.72 ml of a solution 2.5 M BuLi in hexane) over a period of 10 minutes. After 30 min, the solution was warmed to −20° C. and 2N hydrochloric acid (7.5 ml) was added dropwise. The mixture was partitioned between water (50 ml) and diethyl ether (50 ml). The aqueous layer was isolated and the pH of the solution was adjusted to pH=7 by the addition of sodium bicarbonate. The aqueous solution was extracted with ethyl acetate. The combined organic layers were dried (MgSO4) and evaporated under reduced pressure affording 2-trifluoromethyl-imidazo[1,2-a]pyridine-6-boronic acid q (0.23 g, yield=11.4%, purity (LC)=67%).

1. customThe mixture was partitioned between water (50 ml) and diethyl ether (50 ml)
2. customThe aqueous layer was isolated
3. extractionThe aqueous solution was extracted with ethyl acetate
4. dry with materialThe combined organic layers were dried (MgSO4)
5. customevaporated under reduced pressure

ORD record

ord-0b50fe3a9c6f461fa27391997c55dc15

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07615639B2