Trifluoroacetic acid → Omarigliptin

Participants

Reaction Steps

Removal of the BOC group in the product from Step A (13.78 g, 27.67 mmol) was accomplished with trifluoroacetic acid (100 ml) in dichloromethane (200 mL) at room temperature. After stirring for 2 h, the reaction was concentrated and neutralized with 25% MeOH and 2.5% ammonium hydroxide in dichloromethane. Solvents were removed under reduced pressure and the resulting crude material was purified on a 65i Biotage™ column eluting with 1.25-5% MeOH and 0.125-0.5% ammonium hydroxide in dichloromethane. The isolated material was further purified by recrystallization from 5:1 EtOAc/CH2Cl2 at 60° C. The crystalline product was washed with cold 2:1 EtOAc/hexanes to give the title compound as a light brown solid. 1H NMR (500 MHz, CD3OD): 1.71 (q, 1H, J=12 Hz), 2.56-2.61 (m, 1H), 3.11-3.18 (m, 1H), 3.36-3.40 (m, 1H), 3.48 (t, 1H, J=12 Hz), 3.88-3.94 (m, 4H), 4.30-4.35 (m, 1H), 4.53 (d, 1H, J=12 Hz), 7.14-7.23 (m, 2H), 7.26-7.30 (m, 1H), 7.88 (s, 1H). LC-MS: 399.04 (M+1).

Provenance & Evidence