1: 40 percent / benzyltrimethylammonium chloride / CH2Cl2; H2O 2: 50 percent / KH / 2-methyl-propan-2-ol / 1.5 h / Ambient temperature 3: 68 percent / dimethylformamide / 4 h / Heating 4: 1.) NaH, 2.) K2CO3 / 1.) DMF, RT, 0.5 h, 2.) DMF, a) overnight, b) reflux, 1.5 h View Scheme

1: 68 percent / dimethylformamide / 4 h / Heating 2: 1.) NaH, 2.) K2CO3 / 1.) DMF, RT, 0.5 h, 2.) DMF, a) overnight, b) reflux, 1.5 h View Scheme

1: 50 percent / KH / 2-methyl-propan-2-ol / 1.5 h / Ambient temperature 2: 68 percent / dimethylformamide / 4 h / Heating 3: 1.) NaH, 2.) K2CO3 / 1.) DMF, RT, 0.5 h, 2.) DMF, a) overnight, b) reflux, 1.5 h View Scheme

sodium hydride; potassium carbonate 1.) DMF, RT, 0.5 h, 2.) DMF, a) overnight, b) reflux, 1.5 h; Multistep reaction;