1,8-diazabicyclo[5.4.0]undec-7-ene in N,N-dimethyl-formamide T=230°C; 0.333333 h; microwave irradiation; Title compound not separated from byproducts;

toluene-4-sulfonic acid in benzene 20 h; Heating;

1: 99 percent / potassium hydrogen sulfate / 120 °C 2: naphthalenelithium / tetrahydrofuran / 0.08 h / -70 °C 3: dimethyl sulfate, sodium hydroxide; 20 percent sulfuric acid / H2O; toluene / 2 h / Ambient temperature 4: p-toluenesulfonic acid / benzene / 20 h / Heating View Scheme

1: naphthalenelithium / tetrahydrofuran / 0.08 h / -70 °C 2: dimethyl sulfate, sodium hydroxide; 20 percent sulfuric acid / H2O; toluene / 2 h / Ambient temperature 3: p-toluenesulfonic acid / benzene / 20 h / Heating View Scheme

toluene-4-sulfonic acid in benzene 20 h; Heating; Yield given;