Trifluoroacetic acid → HCID 51349195, compound

Participants

Reaction Steps

To a solution of (7R)—N—((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-1-azaspiro[4.4]nonane-7-carboxamide (from experiment 9, step C, peak 3, 13 mg, 0.027 mmol) in dichloromethane (0.5 mL) was added triethylamine (7.39 μL, 0.053 mmol) and acetic anhydride (4.06 mg, 0.040 mmol). The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was subjected to preparative HPLC (Shimadzu VP-ODS 20×100 mm, 8 min. gradient, Solvent A: 10% MeOH, 90% H2O, 0.1% TFA; Solvent B: 90% MeOH, 10% H2O, 0.1% TFA). The peak corresponding to the desired product was collected, concentrated and freeze dried to give (7R)-1-acetyl-N—((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-1-azaspiro[4.4]nonane-7-carboxamide (6 mg, 0.011 mmol, 42.5% yield) as a solid. Anal. RP-HPLC: Retention time=3.44 min (YMC S5 ODS 4.6×50 mm; gradient solvent A: 10% MeOH, 90% H2O, 0.2% H3PO4; Solvent B: 90% MeOH, 10% H2O, 0.2% H3PO4). Purity: >95%; MS (ESI) m/z 532 M+

Provenance & Evidence