1.1: tert.-butyl lithium / diethyl ether / 1.67 h / -78 - -20 °C / |Inert atmosphere 1.2: 1.5 h / -78 - -10 °C / |Inert atmosphere 2.1: didodecanoyl peroxide; dithiocarbonic acid S-[2-(2,4-difluoro-phenyl)-2-oxo-ethyl] ester O-ethyl ester / ethyl acetate / |Inert atmosphere; |Reflux View Scheme