Carbon Dioxide → 2-(tert-Butoxycarbonylamino)-3-fluoro-benzoic acid

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Reaction Steps

A solution of tert-butyllithium in pentane (1.7M, 34 ml, 58 mmol) was added with caution to a solution of (2-fluoro-phenyl)-carbamic acid tert-butyl ester whilst cooling to less than −50° C. The mixture was maintained at this temperature, stirred for 3 h then poured onto a slurry of THF and dry ice. The mixture was allowed to warm to room temperature, diluted with water and evaporated in vacuo. The residue was taken up in water and washed with diethyl ether. A solution of 0.3M potassium hydrogen sulphate was added until pH6 and extracted with chloroform. The chloroform extracts were combined, washed with brine, dried and reduced to give a white solid; yield 2.7 g, 37%.

Provenance & Evidence