反应详情

To a solution of 1-(3-amino-4-hydroxy-phenyl)-cyclopropanecarboxylic acid methyl ester (2.0 g, 9.6 mmol) in THF (40 mL) was added triphosgene (4.2 g, 14 mmol) at room temperature. The mixture was stirred for 20 minutes at this temperature before water (20 mL) was added dropwise at 0° C. The resulting mixture was extracted with EtOAc (100 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under vacuum to give 1-(2-oxo-2,3-dihydro-benzooxazol-5-yl)-cyclopropanecarboxylic acid methyl ester (2.0 g, 91%), which was directly used in the next step. 1H NMR (CDCl3, 300 MHz) δ 8.66 (s, 1H), 7.13-7.12 (m, 2H), 7.07 (s, 1H), 3.66 (s, 3H), 1.68-1.65 (m, 2H), 1.24-1.20 (m, 2H).

1. additionwas added dropwise at 0° C
2. extractionThe resulting mixture was extracted with EtOAc (100 mL×3)
3. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
4. customevaporated under vacuum