Trifluoroacetic acid → 4-{(2S)-3-[7-(2-Aminoethyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]-2-hydroxypropoxy}benzonitrile

tert-Butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-di-azabicyclo[3.3.1]non-3-yl}ethylcarbamate (2.9 g, 6.56 mmol; see WO 01/28992) was dissolved in DCM (30 mL). Trifluoroacetic acid (22.2 g, 194.7 mmol) was added and the solution was stirred for 2 h. The mixture was concentrated under reduced pressure, redissolved in toluene and acetonitrile and concentrated in vacuo again. The product mixture was dissolved in acetonitrile (50 mL) and solid K2CO3 (9.7 g, 10.2 mmol) was added. The mixture was filtered and concentrated under reduced pressure. The mixture was then redissolved in a mixture of EtOAc and a saturated solution of NaHCO3. The mixture was extracted twice with DCM, the combined organic extracts dried (Na2SO4) and evaporated to afford 1.6 g (68.7%) of the title compound.