33233-67-9

56-91-7

24424-99-5

33233-67-9

Phase 1 - Boc Protection: 4-(Aminomethyl)benzoic acid (10.00 g, 65.36 mmol) was stirred with di-tert-butyl dicarbonate (28.0 g, 130.72 mmol) in a solvent mixture of deionized water (100 mL) and tetrahydrofuran (100 mL) at room temperature. The reaction system was adjusted to pH ≈ 6 by slow addition of saturated aqueous sodium bicarbonate solution and the reaction was continuously stirred for 16 hours. Upon completion of the reaction, the reaction solution was carefully acidified to pH ≈ 3 with 1 M hydrochloric acid solution, at which time a white solid precipitated. The solid product was collected by filtration and washed with deionized water and dried to afford 4-[(tert-butoxycarbonylamino)methyl]benzoic acid as a white solid (16.1 g, 97% yield). Mass spectrometry analysis showed m/z = 274 [M + Na]+.