反应详情

A solution of 5-(3-(pyridin-2-yl)isoxazol-5-yl)-3-p-tolyl-1,2,4-oxadiazole (1.0 g, 3.29 mmol), 1-iodopyrrolidine-2,5-dione (1.11 g, 4.76 mmol), and PdOAc2 (0.148 g, 0.657 mmol) in acetonitrile (14 mL) was heated to 120° C. via microwave for 40 minutes. The reaction was repeated 4 additional times on a similar scale, and the contents of each reaction tube were combined, concentrated, and purified by flash silica gel chromatography (eluting with Hexanes/EtOAc—4/1) to yield 5-(4-iodo-3-(pyridin-2-yl)isoxazol-5-yl)-3-p-tolyl-1,2,4-oxadiazole (5.35 g, 76% yield). The compound had an HPLC retention time=3.81 minutes (YMC-Combi 4.6×50 mm S-5 ODS column) eluting with 10-90% aqueous methanol+0.2% phosphoric acid over a 4 minute gradient. MS: (M+H)=431+. 1H NMR (400 MHz, CDCl3) δ ppm 2.46 (s, 3H), 7.36 (d, J=8.03 Hz, 2H), 7.46-7.52 (m, 1H), 7.90 (td, J=7.72, 1.63 Hz, 1H), 8.01 (d, J=7.78 Hz, 1H), 8.12 (d, J=8.28 Hz, 2H), and 8.86 (d, J=4.27 Hz, 1H).

1. customthe contents of each reaction tube were combined
2. concentrationconcentrated
3. custompurified by flash silica gel chromatography (eluting with Hexanes/EtOAc—4/1)