1: 1,8-diazabicyclo[5.4.0]undec-7-ene / N,N-dimethyl-formamide / 18 h / 20 - 120 °C 2: sodium hydroxide; water / ethanol / 16 h / 20 °C View Scheme

1: 1,8-diazabicyclo[5.4.0]undec-7-ene / N,N-dimethyl-formamide / 18 h / 20 - 120 °C 2: sodium hydroxide; water / ethanol / 16 h / 20 °C 3: water; acetone / 23 h / 10 - 50 °C 4: hydrogenchloride / water; tert-butyl methyl ether / 1 h / 20 °C / pH 1 View Scheme

1,8-diazabicyclo[5.4.0]undec-7-ene in N,N-dimethyl-formamide T=20 - 120°C; 18 h;