To a solution of 3-{5-[(1S,4S)-2-oxa-5-azabicyclo[2.2.1]hept-5-ylmethyl]-1H-tetrazol-1-yl}-5-(trifluoromethyl)benzamide (Intermediate 32, 100 mg, 0.272 mmol) and triethylamine (0.076 ml, 0.543 mmol) in dichloromethane (5 ml) was added trifluoroacetic anhydride (0.038 ml, 0.272 mmol). The reaction was stirred at room temperature for 4 hours before the addition of trifluoroacetic anhydride (0.038 ml, 0.272 mmol). The reaction was stirred at room temperature for a further three hours. The reaction was partitioned between DCM (5 mL) and water (5 mL). The organic layer was collected via a hydrophobic frit and the solvent removed. The residue was purified by silica chromatography (Biotage SP4, eluting a gradient from 20-80% EtOAc in iso-hexane). The compound was further purified by high pH MDAP to yield the title compound as a white solid (36 mg)
