A suspension of 2-chloro-4-(2-[1,3]dioxan-2-yl-ethyl)-6-(4-fluorophenyl)-pyrido[3,2-d]pyrimidine (9 mg, 0.024 mmol) in iPrOH (0.5 mL) and 30% ammonium hydroxide (4 mL) was heated at 100° C. for 30 minutes. Solvents were concentrated in vacuo and the residue was purified by RP HPLC using a C18 column with a gradient of H2O and 0.1% TFA-acetonitrile, to provide the title compound as a white solid (6 mg, yield: 70%). The resulting title compound was characterised as follows: MS (m/z) 355.0 [M+H]+; HPLC Rt=3.34 minutes (Method A).
