water; sodium hydroxide in ethanol T=20°C; 4 h;

1.1: DBDMH / sulfuric acid / 16 h / 20 °C 2.1: thionyl chloride / -5 °C / Reflux 3.1: acetic acid; iron / tetrahydrofuran / 10 h / Reflux 3.2: 10 h / Reflux 4.1: water; lithium hydroxide hydrate / ethanol / 20 h / 20 °C 4.2: pH 4 View Scheme

1.1: thionyl chloride / -5 °C / Reflux 2.1: acetic acid; iron / tetrahydrofuran / 10 h / Reflux 2.2: 10 h / Reflux 3.1: water; lithium hydroxide hydrate / ethanol / 20 h / 20 °C 3.2: pH 4 View Scheme

1.1: acetic acid; iron / tetrahydrofuran / 10 h / Reflux 1.2: 10 h / Reflux 2.1: water; lithium hydroxide hydrate / ethanol / 20 h / 20 °C 2.2: pH 4 View Scheme

1: acetic acid; sodium nitrite / water 2: sodium hydroxide; water / ethanol / 4 h / 20 °C View Scheme

1.1: thionyl chloride / 1 h / |Reflux 1.2: 0 °C 2.1: potassium hydroxide; [bis(acetoxy)iodo]benzene / 3 h / 0 °C 3.1: water; potassium hydroxide / methanol / 48 h / |Reflux View Scheme