1.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone / water; dichloromethane / 0.17 h / 0 °C 2.1: chloroformic acid ethyl ester; triethylamine / dichloromethane / 2 h / 0 °C / |Inert atmosphere 2.2: 2.5 h / 0 - 25 °C / |Inert atmosphere 3.1: cesium fluoride; methanol / 3 h / 25 °C / |Inert atmosphere View Scheme

1.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane; water / 0.17 h / 0 °C 2.1: chloroformic acid ethyl ester; triethylamine / dichloromethane / 2 h / 0 °C 2.2: 2.5 h / 0 - 20 °C 3.1: cesium fluoride; methanol / 3 h / 20 °C View Scheme