N-Iodosuccinimide → Ethyl 4-iodo-3-(pyridin-2-yl)isoxazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

A suspension of ethyl 3-(pyridin-2-yl)isoxazole-5-carboxylate (Preparation 63B, 6.25 g, 28.6 mmol), Palladium(II) acetate (1.61 g, 7.16 mmol) and 1-iodopyrrolidine-2,5-dione (12.9 g, 57.3 mmol) in acetonitrile (20 mL) was heated in the microwave for 30 minutes at 120° C. LC/MS analysis indicated that approximately 50% conversion had occurred. Additional 1-iodopyrrolidine-2,5-dione (12.9 g, 57.3 mmol) was added, and the reaction mixture heated for an additional 30 min. at 120° C. The reaction mixture was diluted with acetonitrile (25 mL) and filtered through a plug of Celite. The filtrate was concentrated and purified by silica gel column chromatography using an ISCO setup to afford ethyl 4-iodo-3-(pyridin-2-yl)isoxazole-5-carboxylate (4.00 g, 11.6 mmol, 41%). 1H NMR (400 MHz, CDCl3) δ ppm 1.48 (t, 3H), 4.51 (q, J=7.04 Hz, 2H), 7.44 (ddd, J=7.48, 4.84, 1.32 Hz, 1H), 7.82-7.88 (m, 1H), 7.89-7.94 (m, 1H), and 8.81 (ddd, J=4.18, 1.32, 1.10 Hz, 1H).

Provenance & Evidence