1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → [(1S)-2-(3,5-dichloro-1-oxidopyridin-1-ium-4-yl)-1-(3,4-dimethoxyphenyl)ethyl]-4-(tert-butoxycarbonylamino)-2-fluorobenzoate

Participants

Reaction Steps

To a stirred solution of 4-(tert-butoxycarbonylamino)-2-fluorobenzoic acid (0.200 g, 0.78 mmol) and (1S)-2-(3,5-dichloro-1-oxidopyridin-1-ium-4-yl)-1-(3,4-dimethoxyphenyl)ethanol (0.270 g, 0.78 mmol) in dichloromethane (10.0 mL) was added 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (0.300 g, 1.57 mmol) and N,N-dimethylpyridin-4-amine (0.048 g, 0.39 mmol). The reaction was stirred at room temperature for 16 hours. The reaction was quenched by addition of saturated aqueous sodium bicarbonate solution (25.0 mL) and extracted with dichloromethane (×2). The combined organic extracts were dried on magnesium sulphate, filtered, and the solvent removed in vacuo to afford a yellow oil. The crude material was purified by silica gel chromatography eluting sequentially with iso-hexane and 10% methanol in ethyl acetate to afford the title compound as a yellow solid (0.351 g, 77%).

Provenance & Evidence