1: 64.5 g / diazabicycloundecane / benzene / 12 h / 50 °C 2: 1.) NaOH; 2.) 50percent H2SO4 / 1.) water, 3 h, 60 deg C; 2.) 1 h, 50 deg C View Scheme

sodium hydroxide; sulfuric acid; 1,8-diazabicyclo[5.4.0]undec-7-ene 1.) 50 deg.C, benzene; 2.) 60 deg.C; 3.) 50 deg.C; Multistep reaction;