Iodine → 2,5-Dichloro-4-iodopyridine

Under an argon atmosphere, 3 g of 2,5-dichloropyridine was added to 40 ml of tetrahydrofuran, and 11.15 ml of lithium diisopropylamide (2M heptane/tetrahydrofuran/ethylbenzene solution) was added at −78° C. After stirring for 2 hours, 5.66 g of iodine was added, and the mixture was further stirred for 3 hours. The reaction solution was poured into an aqueous saturated sodium thiosulfate solution, and the resultant solution was extracted with tert-butyl=methyl=ether three times, washed with an aqueous saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography to obtain 4 g of 2,5-dichloro-4-iodopyridine.

1. additionwas added at −78° C
2. stirringthe mixture was further stirred for 3 hours
3. extractionthe resultant solution was extracted with tert-butyl=methyl=ether three times
4. washwashed with an aqueous saturated sodium chloride solution
5. dry with materialdried with anhydrous magnesium sulfate
6. concentrationconcentrated

ORD record

ord-b2970d1d096240ea8ebfad6247c08fe7

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08318776B2