in dimethyl sulfoxide T=120°C; 12 h;

1.1: 18-crown-6 ether; copper; potassium carbonate / N,N-dimethyl-formamide / 24 h / Inert atmosphere; Reflux 2.1: n-butyllithium / diethyl ether; hexane / -78 - 0 °C / Inert atmosphere 2.2: -78 - 20 °C / Inert atmosphere 3.1: dimethyl sulfoxide / 12 h / 120 °C View Scheme

1.1: 18-crown-6 ether; copper; potassium carbonate / N,N-dimethyl-formamide / 24 h / Inert atmosphere; Reflux 2.1: n-butyllithium / diethyl ether; hexane / -78 - 0 °C / Inert atmosphere 2.2: -78 - 20 °C / Inert atmosphere 3.1: dimethyl sulfoxide / 12 h / 120 °C View Scheme

1.1: n-butyllithium / diethyl ether; hexane / -78 - 0 °C / Inert atmosphere 1.2: -78 - 20 °C / Inert atmosphere 2.1: dimethyl sulfoxide / 12 h / 120 °C View Scheme