3,4,5-Trimethoxyaniline → 4-[5-Cyano-4-(3,4,5-trimethoxyphenylamino)-thieno[2,3-b]pyridin-2-yl]-butyric acid methyl ester

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Reaction Steps

A mixture of 4-(4-chloro-5-cyano-thieno[2,3-b]pyridin-2-yl)-butyric acid methyl ester (60 mg, 0.20 mmol), 3,4,5-trimethoxyaniline (92 mg, 0.50 mmol), and pyridine hydrochloride (10 mg, 0.09 mmol) in 10 mL of 2-ethoxyethanol is heated at reflux for 24 hours. The solution is cooled and the solvent is evaporated. The residue is purified by flash column chromatography eluting with 1:1 ethyl acetate:hexane to provide 62 mg of 4-[5-cyano-4-(3,4,5-trimethoxy-phenylamino)-thieno[2,3-b]pyridin-2-yl]-butyric acid methyl ester as a tan solid, mp 101–103° C.; 1H NMR (DMSO-d6) δ 1.94 (quintet, J=7 Hz, 2H), 2.41 (t, J=7 Hz, 2H), 2.88 (t, J=7 Hz, 2H), 3.60 (s, 3H), 3.67 (s, 3H), 3.75 (s, 6H), 6.60 (s, 2H), 7.28 (s, 1H), 8.40 (s, 1H), 9.62 (s, 1H); MS 442.1 (M+H)+.

Provenance & Evidence