反应详情

To a mixture of A215 (0.020 g, 0.065 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.019 g, 0.098 mmol), 1-hydroxybenzotriazole (0.013 g, 0.098 mmol), and diisopropylethylamine (0.034 mL, 0.195 mmol) in anhydrous dimethylformamide (2 mL) was added 3-methoxypropionic acid (9.20 μL, 0.098 mmol). The reaction mixture was stirred at room temperature overnight (After ˜3 hr, the reaction mixture became homogenous). The solvent was removed under reduced pressure, and the residue was diluted with dichloromethane, washed with water, and dried over anhydrous sodium sulfate. Concentration under pressure followed by purification by flash silica gel chromatography using a 5% mixture of methanol in dichloromethane afforded 0.018 g (69%) of A216 as a yellow solid. The compound had an HPLC retention time=1.84 min. (Column: Chromolith SpeedROD 4.6×50 mm—4 min.; Solvent A=10% MeOH, 90% H2O, and 0.1% TFA; Solvent B=90% MeOH, 10% H2O, and 0.1% TFA) and a LC/MS M+1=394.37. 1H NMR (400 MHz, CDCl3) δ ppm 2.62 (t, J=7.15 Hz, 2 H) 3.15 (d, J=6.60 Hz, 3 H) 3.54 (s, 3 H) 3.78 (t, J=7.15 Hz, 2 H) 4.01 (s, 3 H) 4.56 (d, J=6.10 Hz, 2 H) 5.49-5.54 (m, 1 H) 6.96-6.98 (m, 2 H) 7.51-7.58 (m, 3 H) 9.98 (s, 1 H)

1. customThe solvent was removed under reduced pressure
2. additionthe residue was diluted with dichloromethane
3. washwashed with water
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationConcentration under pressure
6. customfollowed by purification by flash silica gel chromatography
7. customafforded 0.018 g (69%) of A216 as a yellow solid