To a mixture of the title compound from Step C (240 mg, 1.01 mmol) and N—BOC-piperazine (189 mg, 1.01 mmol), in acetonitrile (5 ml) was added K2CO3 (210 mg, 1.52 mmol) and sodium iodide (152 mg, 1.01 mmol) and the resulting mixture heated at reflux overnight. The mixture cooled and partitioned between water and EtOAc; organic layer washed with sat. NaCl, dried over MgSO4, filtered and evaporated. The residue purified by column chromatography (eluent: 5% MeOH in DCM) to afford the title compound 145 mg (42%) as an orange oil, which solidified on standing. 1H NMR (CDCl3): 1.45 (s, 9H), 1.60 (d, J 6.8 Hz, 3H), 2.46 (m, 2H), 2.69 (m, 2H), 3.49 (m, 4H), 3.97 (q, J 6.8 Hz, 1H), 7.66 (m, 1H), 7.93 (m, 2H), 8.06 (d, J 8.3 Hz, 1H), 9.44 (s, 1H).
