反应详情

A mixture of 4-(5-nitro-thiophen-2-yl)-butyric acid methyl ester (2.29 g, 10.0 mmol) and palladium hydroxide (500 mg, 20% on carbon) in 30 mL of ethyl acetate and 30 mL of methanol is hydrogenated at 50 psi for 48 hours. The reaction mixture is filtered and concentrated. The residue is purified by flash column chromatography eluting with 1:3 ethyl acetate:hexane to provide 1.32 g of 4-(5-amino-thiophen-2-yl)-butyric acid methyl ester as a dark oil; 1H NMR (DMSO-d6) δ 1.74 (m, 2H), 2.38 (m, 2H), 2.54 (m, 2H), 3.59 (s, 3H), 5.66 (d, J=3 Hz, 1H), 6.24 (d, J=3 Hz, 1H); MS 200.2 (M+H)+.

1. filtrationThe reaction mixture is filtered
2. concentrationconcentrated
3. customThe residue is purified by flash column chromatography
4. washeluting with 1:3 ethyl acetate