反应详情

A solution of 3-(4-benzyloxy-phenyl)-4-cyano-1-methyl-1H-pyrrole-2-carboxylic acid ethyl ester. (184.73 g, 0.512 mol, prepared in example E-6a or E-6b) in anhydrous THF (2,000 mL) is treated with NBS (109.47 g, 0.615 mol). The resulting reaction mixture is allowed to stir at room temperature overnight. The reaction mixture is poured into water (2,000 mL). The resulting solution is divided into 2 equal parts, and each is extracted with EtOAc (3×800 mL each). The combined organics are dried over anhydrous MgSO4, filtered, then concentrated in vacuo to afford a yellow solid. The yellow solid is purified by column chromatography (silica gel, EtOAc/Hexanes 1/3) to afford the title compound (133.99 g, ˜60% yield) as a white solid: 1H NMR (500 MHz; CDCl3) δ 7.46-7.44 (m, 2H), 7.41-7.38 (m, 2H), 7.36-7.32 (m, 1H), 7.29-7.26 (m, 2H), 7.01-6.99 (m, 2H), 5.10 (s, 2H), 4.11 (q, 2H), 3.98 (s, 3H), 1.02 (t, 31); MS(ES): m/z 438.9.

1. customThe resulting reaction mixture
2. extractioneach is extracted with EtOAc (3×800 mL each)
3. dry with materialThe combined organics are dried over anhydrous MgSO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customto afford a yellow solid
7. customThe yellow solid is purified by column chromatography (silica gel, EtOAc/Hexanes 1/3)