反应详情

A solution of 2-[2-(3-methyl-4-chloro-pyridin-2-yl)-2-cyclopropyl-ethylidene]-malonic acid diethyl ester (5.76 g, 16.4 mmol) in Dowtherm A (80 mL) was heated in a preheated oil bath at 230° C. for 15 min. The reaction mixture was cooled to room temperature and purified by flash silica column chromatography (hexane:ethyl acetate, 2:1 to 1:2) to afford the title compound as a yellow solid (3.76 g, 75%). ESI-MS m/z: 306 (M+H)+; 1H NMR (CDCl3, 300 MHz) δ ppm: 9.34 (d, J=7.8 Hz, 1H), 8.40 (s, 1H), 7.12 (d, J=7.8 Hz, 1H), 4.41 (q, 2H), 3.00 (s, 3H), 2.28-2.33 (m, 1H), 1.42 (t, 3H), 1.03-1.08 (m, 2H), 0.71-0.76 (m, 2H).

1. custompurified by flash silica column chromatography (hexane:ethyl acetate, 2:1 to 1:2)