反应详情

To a stirred solution of ethyl 4-amino-2,5-difluorophenylacetate (323 mg, 1.5 mmol) in DMF (8 mL), were added triethylamine (0.209 ml, 1.5 mmol) and 2-methylphenyl isocyanate (0.372 ml, 3.0 mmol) at rt. The stirring was continued for 48 hour at 80° C. The reaction mixture was evaporated in vacuo, and the solid was suspended to n-hexane. The solid was collected through filtration. The solid was dissolved in THF-MeOH (1:1, v/v, 20 mL), and was added 4M NaOH (10 mL) at rt. The stirring was continued for 18 hours at rt. The reaction was poured into 1M HCl, and the resulting precipitate was collected through filtration. The solid was recrystallized with CHCl3-n-hexane to give 4-[(2-methylphenyl)ureido]-2,5-difluorophenylacetic acid (214 mg, 46%) as a white solid. 1H-NMR (CDCl3) δ 2.30 (s, 3 H), 3.35 (m, 2 H), 7.02 (m, 2 H), 7.18 (d, J=7.3 Hz, 2 H), 7.69 (d, J=7.8 Hz, 1 H), 8.03 (m, 1 H); MS (FAB) m/z 321 (M++1).

1. customThe reaction mixture was evaporated in vacuo
2. filtrationThe solid was collected through filtration
3. dissolutionThe solid was dissolved in THF-MeOH (1:1, v/v, 20 mL)
4. additionwas added 4M NaOH (10 mL) at rt
5. waitThe stirring was continued for 18 hours at rt
6. additionThe reaction was poured into 1M HCl
7. filtrationthe resulting precipitate was collected through filtration
8. customThe solid was recrystallized with CHCl3-n-hexane