trifluoroacetic acid in dichloromethane 1.5 h; Ambient temperature;

1: 51.1 percent / K2CO3 / dimethylformamide / 1.5 h / -40 °C 2: 73 percent / trifluoroacetic acid / CH2Cl2 / 1.5 h / Ambient temperature View Scheme

1: 51.1 percent / K2CO3 / dimethylformamide / 1.5 h / -40 °C 2: 73 percent / trifluoroacetic acid / CH2Cl2 / 1.5 h / Ambient temperature View Scheme

1: trifluoroacetic acid / CH2Cl2; various solvent(s) / 2 h / 0 °C 2: 51.1 percent / K2CO3 / dimethylformamide / 1.5 h / -40 °C 3: 73 percent / trifluoroacetic acid / CH2Cl2 / 1.5 h / Ambient temperature View Scheme

1: 1.) triethylamine, methanesulfonyl chloride, 2.) triethylamine / 1.) CH2Cl2, -50 deg C, 2.) CH2Cl2, -50 deg C 2: trifluoroacetic acid / CH2Cl2; various solvent(s) / 2 h / 0 °C 3: 51.1 percent / K2CO3 / dimethylformamide / 1.5 h / -40 °C 4: 73 percent / trifluoroacetic acid / CH2Cl2 / 1.5 h / Ambient temperature View Scheme

1.1: ethyl acetate / 4 h / -50 °C / Inert atmosphere 2.1: water / 1 h / -50 - 20 °C / Inert atmosphere 3.1: water / 0.5 h / 20 °C / Inert atmosphere 4.1: sodium hydrogencarbonate / water / Inert atmosphere 4.2: 20 °C / Inert atmosphere 5.1: formic acid; titanium tetrachloride / dichloromethane / 1.25 h / 0 - 20 °C / Inert atmosphere View Scheme

1.1: hydrogenchloride / ethyl acetate / 1.5 h / -50 °C / Inert atmosphere 2.1: ethyl acetate / 4 h / -50 °C / Inert atmosphere 3.1: water / 1 h / -50 - 20 °C / Inert atmosphere 4.1: water / 0.5 h / 20 °C / Inert atmosphere 5.1: sodium hydrogencarbonate / water / Inert atmosphere 5.2: 20 °C / Inert atmosphere 6.1: formic acid; titanium tetrachloride / dichloromethane / 1.25 h / 0 - 20 °C / Inert atmosphere View Scheme

1.1: sodium hydrogencarbonate / water / Inert atmosphere 1.2: 20 °C / Inert atmosphere 2.1: formic acid; titanium tetrachloride / dichloromethane / 1.25 h / 0 - 20 °C / Inert atmosphere View Scheme

1.1: diisopropylamine / tetrahydrofuran / -30 °C / Inert atmosphere 1.2: 0.5 h / Inert atmosphere 2.1: hydrogenchloride / ethyl acetate / 1.5 h / -50 °C / Inert atmosphere 3.1: ethyl acetate / 4 h / -50 °C / Inert atmosphere 4.1: water / 1 h / -50 - 20 °C / Inert atmosphere 5.1: water / 0.5 h / 20 °C / Inert atmosphere 6.1: sodium hydrogencarbonate / water / Inert atmosphere 6.2: 20 °C / Inert atmosphere 7.1: formic acid; titanium tetrachloride / dichloromethane / 1.25 h / 0 - 20 °C / Inert atmosphere View Scheme

1.1: sodium hydroxide / methanol; water / 2.5 h / -30 °C / Inert atmosphere 1.2: 1 h / 0 °C / pH 3.5 / Inert atmosphere 2.1: diisopropylamine / tetrahydrofuran / -30 °C / Inert atmosphere 2.2: 0.5 h / Inert atmosphere 3.1: hydrogenchloride / ethyl acetate / 1.5 h / -50 °C / Inert atmosphere 4.1: ethyl acetate / 4 h / -50 °C / Inert atmosphere 5.1: water / 1 h / -50 - 20 °C / Inert atmosphere 6.1: water / 0.5 h / 20 °C / Inert atmosphere 7.1: sodium hydrogencarbonate / water / Inert atmosphere 7.2: 20 °C / Inert atmosphere 8.1: formic acid; titanium tetrachloride / dichloromethane / 1.25 h / 0 - 20 °C / Inert atmosphere View Scheme