1.1: potassium carbonate / N,N-dimethyl-formamide / 24 h / 30 °C 2.1: toluene; tetrahydrofuran / 0.5 h / 0 °C / Inert atmosphere 2.2: 4 h / 20 °C View Scheme

1.1: potassium carbonate / N,N-dimethyl-formamide / 24 h / 30 °C 2.1: lithium diisopropyl amide / n-heptane; tetrahydrofuran; ethylbenzene / 0.5 h / 0 °C / Inert atmosphere 2.2: 15 h / 20 °C 2.3: 3 h / 20 °C View Scheme