Synthesis
General procedure for the synthesis of 4-(N-tert-butoxycarbonylamino)benzoic acid from di-tert-butyl dicarbonate and p-aminobenzoic acid: sodium hydroxide (1.46 g, 36.5 mmol) was added to a mixture of dioxane (70 mL) and water (35 mL) of 4-aminobenzoic acid (5.00 g, 36.5 mmol), followed by di-tert-butyl dicarbonate (11.9 g, 54.8 mmol). The reaction mixture was stirred at room temperature for 24 hours. Upon completion of the reaction, the solvent was removed by rotary evaporation and aqueous 3N hydrochloric acid was added slowly and dropwise to the residue to adjust the pH to 3. The precipitate precipitated was collected by filtration, washed with water and dried to afford the target product 4-(N-tert-butoxycarbonylamino)benzoic acid (8.28 g, 96% yield) as a white solid.
References
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[2] Journal of Catalysis, 2016, vol. 340, p. 344 - 353
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[4] Synthesis, 2005, # 7, p. 1061 - 1068
[5] Chemistry - A European Journal, 2003, vol. 9, # 2, p. 557 - 560
