Hydrochloric Acid → (S)-methyl 2-(((9H-fluoren-9-yl)methoxy)carbonylamino)-3-(4-aminophenyl)propanoate

Participants

Reaction Steps

In a hydrogenation reactor, (S)-methyl 2-(((9H-fluoren-9-yl)methoxy)carbonylamino)-3-(4-nitrophenyl)propanoate (3B; 25 g, 56 mmol) was dissolved in THF (200 mL), and 15 mL of 4N HCl was added to the reaction mixture. Then, 10% Pd/C (2.5 g) was added to the reaction mixture. Hydrogen was introduced into the reactor until pressure reached 4 MPa. The reaction was stirred at room temperature for 1 hour. The catalyst was removed by filtration and washed with THF. The pH of the solution was adjusted to about 7 by adding saturated NaHCO3 (aq) while the solution was on an ice bath. The organic layer was separated, and the aqueous layer was washed with CH2Cl2 (2×15 mL). The combined organic fractions were dried with anhydrous Na2SO4 to give a solution of (S)-methyl 2-(((9H-fluoren-9-yl)methoxy)carbonylamino)-3-(4-aminophenyl)propanoate 3C. The solution was used directly in step 3.

Provenance & Evidence