1.1: acetonitrile / 0.5 h / 20 °C 2.1: lithium trifluoromethane sulfonate / N,N-dimethyl-formamide / 0.5 h / 0 °C / Molecular sieve; Inert atmosphere 2.2: 0 °C / Inert atmosphere 2.3: 0 - 20 °C / Inert atmosphere 3.1: water; acetic acid / acetonitrile / 17 h / 80 °C 3.2: 17 h / 70 °C View Scheme

1.1: acetonitrile / 0.5 h / 20 °C 2.1: lithium trifluoromethane sulfonate / N,N-dimethyl-formamide / 0.5 h / 0 °C / Molecular sieve; Inert atmosphere 2.2: 0 °C / Inert atmosphere 2.3: 0 - 20 °C / Inert atmosphere 3.1: water; acetic acid / acetonitrile / 17 h / 80 °C View Scheme