Trifluoroacetic acid → HCID 86620596, compound

Participants

Reaction Steps

Trifluoroacetic acid (0.063 mL, 0.82 mmol) was added to a room temperature solution of [(S)-1-(1H-Benzimidazol-2-yl)-2-(4-benzyloxy-phenyl)-ethyl]-carbamic acid tert-butyl ester (0.073 g, 0.16 mmol) in CH2Cl2 (10 mL). The resulting solution was stirred at room temperature for 2 hours, and then concentrated in vacuo to give (S)-1-(1H-Benzimidazol-2-yl)-2-(4-benzyloxy-phenyl)-ethylammonium trifluoro-acetate as a red-brown oil. This material was re-suspended in CH2Cl2 (4 mL) and treated with a room temperature solution of PyBOP (0.086 g, 0.16 mmoles), triethylamine (0.080 mL, 0.58 mmol), and (S)-1-(3-Trifluoromethyl-benzenesulfonyl)-piperidine-2-carboxylic acid (0.056 g, 0.16 mmol) in CH2Cl2 (4 mL). The resulting mixture was stirred at room temperature for 16 h. Purification of the product by flash chromatography on silica gel eluting with 10-50% EtOAc/heptane afforded 0.075 g (69%) of the title compound as a colorless powder: ES+ LC/MS m/e 663 (M+H), 100% purity; 1H NMR (CDCl3) ˜1:1 mixture of diastereomers δ10.07 (bd s, 1), 8.07 (s, 1), 7.95 (d, 1, J=7.8 Hz), 7.81 (m, 1), 7.60 (m, 1), 7.24-7.42 (m, 9), 7.10 (d, 2, J=8.6 Hz), 6.88 (d, 2, J=8.6 Hz), 5.25-5.42 (m, 1), 5.04 (s, 2), 4.48 (bd s, 1), 3.32-3.84 (m, 3), 2.88 (m, 1), 1.05-1.77 (m, 6).

Provenance & Evidence