1: t-BuOK / 2-methyl-propan-2-ol / 18 h / 50 °C 2: HCl / acetic acid / 2 h / 100 °C View Scheme

potassium carbonate in N,N-dimethyl-formamide T=140 - 150°C; 2 h;

1: t-BuOK / 2-methyl-propan-2-ol / 18 h / 50 °C 2: HCl / acetic acid / 2 h / 100 °C 3: 87 percent / DBU / acetonitrile / 1.) reflux, 2.5 h, 2.) room temperature, overnight View Scheme