1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / 0 °C 1.2: 3 h / 0 °C 2.1: bromine; pyridine / dichloromethane / 2 h / 0 °C 3.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h 4.1: sodium hydroxide; tetrabutylammomium bromide / dichloromethane / 0.08 h / 0 °C 4.2: 12.25 h / 0 - 25 °C View Scheme