1: 2-chloro-4-(ethylsulfonyl)-3-fluoroaniline With thionyl chloride; triethylamine in acetonitrile T=45°C; 2 h; 2: (R)-(+)-2-hydroxy-2-methyl-3,3,3-trifluoropropanoic acid in acetonitrile T=20°C;

1.1: trifluorormethanesulfonic acid / 18 h / 70 - 130 °C 2.1: 1-methyl-pyrrolidin-2-one / 168 h / 20 °C 3.1: palladium diacetate; triphenylphosphine; N,N'-dimethyl-barbituric acid / dichloromethane / 96 h / 45 °C / |Inert atmosphere 4.1: triethylamine; thionyl chloride / acetonitrile / 2 h / 45 °C 4.2: 20 °C View Scheme

1.1: tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 2.1: dihydrogen peroxide / acetic acid; water / 3 h / 75 °C 3.1: triethylamine; trichlorophosphate / 60 h / 105 °C 4.1: sodium dithionite / water / 1.5 h / 75 °C 5.1: triethylamine; thionyl chloride / acetonitrile / 2 h / 45 °C 5.2: 20 °C View Scheme