反应详情

A stirred mixture of tert-butyl 4-[N′-(2-iodophenyl)ureido]-3-methoxyphenylacetate (3.93 g, 8.16 mmol) and TFA (5 ml) in CH2Cl2 (5 ml) was refluxed for 3 h. After cooling to rt, the mixture was concentrated in vacuo and H2O (50 ml) was added to this residue. The resulting precipitate was collected by filtration and purified by column chromatography on silica gel with CHCl3—MeOH (9:1) as eluent to give 4-[N′-(2-iodophenyl)ureido]-3-methoxyphenylacetic acid (2.89 g, 83%) as a pale yellow crystalline powder. 1H-NMR (DMSO-d6) δ3.62 (s, 2 H), 3.88 (s, 3 H), 6.78 (d, J=8.3 Hz, 1 H), 6.83-6.87 (m, 1 H), 6.94 (s, 1 H), 7.32-7.36 (m, 1 H), 7.69 (dd, J=8.3, 1.5 Hz, 1 H), 7.84 (dd, J=8.3, 1.5 Hz, 1 H), 7.97-8.00 (m, 1 H), 8.55 (m, 1H), 8.82 (m, 1 H), 12.26 (br s, 1 H).

1. temperaturewas refluxed for 3 h
2. concentrationthe mixture was concentrated in vacuo and H2O (50 ml)
3. additionwas added to this residue
4. filtrationThe resulting precipitate was collected by filtration
5. custompurified by column chromatography on silica gel with CHCl3—MeOH (9:1) as eluent