1.1: trifluorormethanesulfonic acid / |Cooling with ice 1.2: 2 h / 25 °C / |Cooling with ice 2.1: potassium tert-butylate / tetrahydrofuran / |Reflux 3.1: N,N-dimethyl-formamide / 20 - 70 °C View Scheme

1: With methanol; lithium hydroxide; water in tetrahydrofuran T=20°C; 72 h; 2: With hydrogenchloride; water in tetrahydrofuran; methanol

in diethylene glycol dimethyl ether T=100°C; 16 h;

in sodium hydroxide T=90°C; pH=13.5; 7 h;