反应详情

To a stirred solution of tert-butyl 4-amino-3-methylphenylacetate (1.09 g, 4.93 mmol) and Et3N (755 ml, 5.42 mmol) in THF (10 ml) was added 2-fluorophenyl isocyanate (610 μl, 5.44 mmol) and the reaction mixture was stirred at room temperature overnight. The reaction mixture was concentrated to a small volume and diluted with n-hexane. Resulting precipitate was collected under a reduced pressure and the filtrate was washed with n-hexane to give tert-butyl 4-[N′-(2-fluorophenyl)ureido]-3-methylphenylacetate (1.31 g, 74%) as a white crystalline powder. mp 89-91° C.; 1H-NMR (CDCl3) δ1.47 (s, 9 H), 2.06 (s, 3 H), 3.49 (s, 2 H), 6.62 (s, 1 H), 6.92-7.09 (m, 5 H), 7.21 (br s, 1 H), 7.49-7.51 (m, 1 H), 8.10-8.15 (m, 1 H); Anal. Calcd. for C20H23FN2O3; C, 67.02; H, 6.47; N, 7.82; F, 5.30. Found: C, 66.74; H, 6.35; N, 7.85; F, 5.69.

1. concentrationThe reaction mixture was concentrated to a small volume
2. additiondiluted with n-hexane
3. customResulting precipitate
4. customwas collected under a reduced pressure
5. washthe filtrate was washed with n-hexane