1: 1) hexamethyldisilazane, (NH4)2SO4 / 1) reflux, 20 h; 2) DMF, 80 deg C, 18 h 2: conc. HCl / acetic acid; H2O / 36 h / Heating 3: 1) 1,4-diazabicyclo<2.2.2>octane / 1) room temp., 15 min., DMSO; 2) 70 deg C, 18 h View Scheme

1: conc. HCl / acetic acid; H2O / 36 h / Heating 2: 1) 1,4-diazabicyclo<2.2.2>octane / 1) room temp., 15 min., DMSO; 2) 70 deg C, 18 h View Scheme

1: 1) hexamethyldisilazane, (NH4)2SO4 / 1) reflux, 20 h; 2) DMF, 80 deg C, 18 h 2: conc. HCl / acetic acid; H2O / 36 h / Heating 3: 1) 1,4-diazabicyclo<2.2.2>octane / 1) room temp., 15 min., DMSO; 2) 70 deg C, 18 h View Scheme

1,4-diaza-bicyclo[2.2.2]octane 1) room temp., 15 min., DMSO; 2) 70 deg C, 18 h; Yield given. Multistep reaction;