Iodine → 2-Fluoro-3-iodo-5-isopropylpyridine

Participants

Reaction Steps

To a stirring solution of 9.2 mL of LDA (lithium diisopropylamide) (2.0M solution in THF/heptane/ethylbenzene) in 20 mL of THF at −78° C. was added 2-fluoro-5-isopropylpyridine in 40 mL of THF dropwise over a period of 20 min. After 30 min. 4.39 g (17.3 mmol) of iodine in 25 mL of THF was added. After 2 h at −78° C. with the light off, 20 mL of water was added, and the cold bath was removed. Water (80 mL) was added and 9 g of sodium thiosulfate was added in 3 portions. Diethyl ether was added, and the layers were separated. The organic layer was washed with brine, dried over Na2SO4, filtered, and concentrated. Purification by flash silica gel chromatography (5% Et2O/hexanes) provided 1.83 g of 2-fluoro-3-iodo-5-isopropylpyridine with some impurity.

Provenance & Evidence