in dichloromethane T=-10 - 20°C; 12 h;

1.1: hydrazine hydrate / ethanol / 15 h / Inert atmosphere; Reflux 2.1: toluene-4-sulfonic acid / dichloromethane / 5 h / Reflux; Inert atmosphere 3.1: n-butyllithium / tetrahydrofuran / 0.25 h / -80 °C / Inert atmosphere 3.2: 2 h / -80 - 20 °C / Inert atmosphere 4.1: hydrogenchloride / methanol / 2 h / Inert atmosphere; Reflux 5.1: sulfur(IV) fluoride; hydrogen fluoride / 5 h / 100 °C / Autoclave View Scheme

1.1: toluene-4-sulfonic acid / dichloromethane / 5 h / Reflux; Inert atmosphere 2.1: n-butyllithium / tetrahydrofuran / 0.25 h / -80 °C / Inert atmosphere 2.2: 2 h / -80 - 20 °C / Inert atmosphere 3.1: hydrogenchloride / methanol / 2 h / Inert atmosphere; Reflux 4.1: sulfur(IV) fluoride; hydrogen fluoride / 5 h / 100 °C / Autoclave View Scheme