Carbon tetrabromide → 2-(4-Bromobutyl)-4-[(3,4,5-trimethoxyphenyl)amino]-thieno[2,3-b]pyridine-5-carbonitrile

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Reaction Steps

To a solution of 2-(4-hydroxybutyl)-4-[(3,4,5-trimethoxyphenyl)amino]-thieno[2,3-b]pyridine-5-carbonitrile (413 mg, 1.0 mmol) and carbon tetrabromide (464 mg, 1.4 mmol) in 10 mL of dichloromethane is added a solution of triphenylphosphine (314 mg, 1.2 mmol) in 5 mL of dichloromethane with stirring. The mixture is stirred at room temperature for 2 hours and concentrated. The residue is purified by flash column chromatography eluting with a gradient of 9:1 hexane:ethyl acetate to 1:2 hexane:ethyl acetate to provide crude 2-(4-bromobutyl)-4-[(3,4,5-trimethoxyphenyl)amino]-thieno[2,3-b]pyridine-5-carbonitrile. The crude 2-(4-bromobutyl)-4-[(3,4,5-trimethoxyphenyl)amino]-thieno[2,3-b]pyridine-5-carbonitrile is heated 70° C. in 2 mL of morpholine in the presence of sodium iodide (100 mg, 0.67 mmol) for 1 hour. The mixture is concentrated, and the residue is purified by flash column chromatography eluting with a gradient of ethyl acetate to 10% methanol in ethyl acetate to provide 2-[4-(4-morpholinyl)butyl]-4-[(3,4,5-trimethoxyphenyl)amino]-thieno[2,3-b]pyridine-5-carbonitrile as a yellow oil; 1H NMR (DMSO-d6) δ 1.49 (quintet, J=7 Hz, 2H), 1.68 (quintet, J=7 Hz, 2H), 2.31 (m, 6H), 2.87 (t, J=7 Hz, 2H), 3.55 (m, 4H), 3.67 (s, 3H), 3.74 (s, 6H), 6.59 (s, 2H), 7.23 (s, 1H), 8.37 (s, 1H), 9.46 (s, 1H); MS 483.5 (M+H)+.

Provenance & Evidence