1.1: toluene / 3 h / 90 °C 1.2: 14 h / 50 °C 2.1: hydrogenchloride; water; acetic acid; iron / ethanol / 0.5 h / 0 - 20 °C 3.1: sodium nitrite; sulfuric acid / N,N-dimethyl-formamide; water / 1.5 h / 0 °C 3.2: 0.42 h / 20 - 90 °C View Scheme