Iodine → 2,3-Dichloro-4-iodopyridine

Temperature

-70 °C

With cooling with ice, 2.66 M n-butyllithium (100 mL, 0.266 mmol) was added to a tetrahydrofuran (400 mL) solution of diisopropylamine (11.9 mL, 84.2 mmol), cooled to −70° C., and stirred for 0.5 hours. A tetrahydrofuran (170 mL) solution of 2,3-dichloropyridine (35 g, 0.24 mmol) was dropwise added to the solution, over 25 minutes, and then stirred at −70° C. for 1 hour. A tetrahydrofuran (170 mL) solution of iodine (75 g, 0.30 mmol) was added to the reaction mixture, and warmed up to room temperature with stirring. Water was added to the reaction mixture, and extracted twice with ethyl acetate. The organic layer was washed with saturated brine, dried with anhydrous sodium sulfate, and concentrated under reduced pressure. Ethyl acetate and hexane were added to the residue, the precipitated matter was taken out through filtration and dried to obtain the entitled compound (46.4 g, 72%) as a pale yellow solid.

1. stirringstirred at −70° C. for 1 hour
2. temperaturewarmed up to room temperature
3. stirringwith stirring
4. extractionextracted twice with ethyl acetate
5. washThe organic layer was washed with saturated brine
6. dry with materialdried with anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure
8. additionEthyl acetate and hexane were added to the residue
9. filtrationthe precipitated matter was taken out through filtration
10. customdried

ORD record

ord-63cdbc32af1745ab917e9dceb6a7864f

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08158652B2