1.1: hydrogenchloride / di-isopropyl ether / -20 - -1 °C 2.1: potassium tert-butylate / N,N-dimethyl-formamide / 0.75 h / -25 °C 2.2: 1 h / -25 °C 3.1: sodium methylate; 2-hydroxyethanethiol / ethanol / 4 h / Reflux 3.2: 0.5 h / 20 °C View Scheme