反应详情

4-Fluoro-2-hydroxy-benzoic acid (74) (0.15 g, 0.961 mmol) was dissolved in DMF (6 mL), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl-uronium hexafluorophosphate (HBTU) (0.382 g, 1.01 mmol) was added followed by iPr2EtN (0.167 mL, 0.961 mmol) and the mixture was shaken in a Teflon septum capped 40 mL I-Chem vial at room temperature for 25 minutes. (4-Amino-3-benzyloxy-phenyl)-carbamic acid 9H-fluoren-9-ylmethyl ester (0.419 g, 0.961 mmol) was added and the mixture was shaken at room temperature for 16 h. LC-MS indicated complete coupling at this point. The mixture was diluted with EtOAc (50 mL), washed with water (25 mL), aqueous saturated NaHCO3 (25 mL) and brine (25 mL) via extraction, dried over MgSO4. The organic layer was concentrated to give a yellow oil. Purification by flash chromatography using a gradient of hexane and EtOAc (eluding with 15–100% EtOAc in hexane in 30 minutes) gave the desired product (75) upon concentration (0.192 g, 0.334 mmol, 35% yield). LC-MS (ESI): (exact mass: 574.19) m/e=575.2 [M+1]+ (100%), 1149.5 [2M+1]+ (25%).

1. customcapped 40 mL I-Chem vial at room temperature for 25 minutes
2. washwashed with water (25 mL), aqueous saturated NaHCO3 (25 mL) and brine (25 mL) via extraction
3. dry with materialdried over MgSO4
4. concentrationThe organic layer was concentrated
5. customto give a yellow oil
6. customPurification by flash chromatography
7. customa gradient of hexane and EtOAc (eluding with 15–100% EtOAc in hexane in 30 minutes)