hydrogenchloride; n-butyllithium; tert-butylamine in tetrahydrofuran; n-heptane; water

1.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone; N,N-bis(trimethylsilyl)-trifluoroacetamide / toluene / 12 h / 25 - 110 °C / Inert atmosphere 2.1: sulfuric acid / 3 h / 20 - 30 °C 2.2: 1.5 h / 0 - 5 °C View Scheme

bis(trimethyl-silyl)-trifluoroacetamide; 2,3-dicyano-5,6-dichloro-p-benzoquinone in 1,4-dioxane 20 deg C, 4 h. then 110 deg C, 18 h.; Yield given;