反应详情

2-Benzyloxy-nicotinic acid (423) (0.157 g, 0.687 mmol) was dissolved in DMF (4 mL), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl-uronium hexafluorophosphate (HBTU) (0.273 g, 0.721 mmol) was added followed by iPr2EtN (0.143 mL, 0.824 mmol) and the mixture was shaken in a Teflon septum capped 40 mL vial at room temperature for 25 minutes. (4-Amino-3-benzyloxy-phenyl)-carbamic acid 9H-fluoren-9-ylmethyl ester (65) (0.3 g, 0.687 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 (25 mL), washed with water (15 mL), NaHCO3 (aqueous saturated, 15 mL) and brine (15 mL) via extraction, dried over MgSO4 and concentrated to give a brown oil. Purification by flash chromatography (eluding with 15–100% EtOAc/hexane in 30 minutes) gave the desired product (424) as a yellow powder upon concentration (0.436 g, 0.673 mmol, 98% yield). LC-MS (ESI): (exact mass: 647.24) m/e=648.3 [M+1]+ (100%).

1. customcapped 40 mL vial at room temperature for 25 minutes
2. washwashed with water (15 mL), NaHCO3 (aqueous saturated, 15 mL) and brine (15 mL) via extraction
3. dry with materialdried over MgSO4
4. concentrationconcentrated
5. customto give a brown oil
6. customPurification by flash chromatography (eluding with 15–100% EtOAc/hexane in 30 minutes)