反应详情

To a stirred solution of tert-butyl 4-amino-3-methylphenylacetate (1.36 g, 6.15 mmol) and triethylamine (170 ml, 1.23 mmol) in THF (30 ml) was added 2-methoxyphenyl isocyanate (820 ml, 6.15 mmol), and the resulting mixture was stirred for 27 h. The mixture was concentrated to a small volume in vacuo, and hexane was added to the residue to give precipitate, which was collected by filtration to give tert-butyl 4-[N′-(2-methoxyphenyl)ureido]-3-methylphenylacetate (1.74 g, 76%) as a white crystalline material. mp 157–158° C.; 1H-NMR (CDCl3) δ 1.46 (s, 9 H), 2.30 (s, 3 H), 3.50 (s, 2 H), 3.76 (s, 3 H), 6.43 (s, 1 H), 6.83 (br d, J=8.4 Hz, 1 H), 6.95 (br d, J=8.0 Hz, 1 H), 6.98–6.99 (m, 2 H), 7.13 (br s, 1 H), 7.23 (br s, 1 H), 7.48 (d, J=8.8 Hz, 1 H), 8.14 (d, J=8.4 Hz, 1 H); MS (ESI) m/z 371 (M++H).

1. concentrationThe mixture was concentrated to a small volume in vacuo, and hexane
2. additionwas added to the residue
3. customto give precipitate, which
4. filtrationwas collected by filtration