Iodine → 2,3-Dichloro-4-iodopyridine

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence