Iodine → 2-Chloro-5-iodopyridin-4-amine

Participants

Reaction Steps

Silver sulfate (7.1 g, 22.8 mmol) and 4-amino-2-chloropyridine (4.06 g, 31.6 mmol) were added to a solution of iodine (5.65 g, 22.3 mmol) in ethanol (100 mL) and the reaction mixture stirred at rt for 72 h. The bright yellow suspension was filtered, washed with methanol and the filtrate concentrated in vacuo. The residue was partitioned between saturated Na2CO3 solution (200 mL) and ethyl acetate (200 ml). After separation the organic layer was washed with Na2S2O3 solution (50 mL, 25%) and brine (50 mL), dried (MgSO4), concentrated in vacuo and purified by chromatography on silica gel eluting with iso-hexane/ethyl acetate (3:1 to 2.5:1) to give the title compound. δH (CDCl3): 4.81 (2H, br s), 6.63 (1H, s), 8.38 (1H, s); m/z (ES+)=254.86 [M+H]+; RT=2.51 min.

Provenance & Evidence