in diethyl ether 2 h; Ambient temperature;

1.1: 37 percent / Lawesson's reagent / CH2Cl2 / 15 h / 25 °C 2.1: KHCO3 / 1,2-dimethoxy-ethane / 2 h / 25 °C 2.2: 48 percent / trifluoroacetic anhydride; pyridine / 1,2-dimethoxy-ethane / 1 h / 20 °C View Scheme

1.1: ethyl chloroformate; triethylamine / tetrahydrofuran / 0.5 h / -10 °C 1.2: aq. NH4OH / tetrahydrofuran / 0.75 h / -10 °C 2.1: 37 percent / Lawesson's reagent / CH2Cl2 / 15 h / 25 °C 3.1: KHCO3 / 1,2-dimethoxy-ethane / 2 h / 25 °C 3.2: 48 percent / trifluoroacetic anhydride; pyridine / 1,2-dimethoxy-ethane / 1 h / 20 °C View Scheme

1: 62 percent / triethylamine / CH2Cl2 / 3 h 2: 88 percent / 2,4-bis(4-phenoxyphenyl)-1,3-dithia-2,4-diphosphetane 2,4-disulfide (PTPS) / tetrahydrofuran / 6 h / Ambient temperature 3: 75 percent / diethyl ether / 48 h / Ambient temperature View Scheme

1: 76 percent / NH3; H2S / methanol / 20 °C 2: 74 percent / CaCO3 / ethanol / 6 h / 20 °C View Scheme

1: KHCO3 / 1,2-dimethoxy-ethane / 16 h / -15 °C 2: TFAA, 2,6-lutidine / 1,2-dimethoxy-ethane / 0.5 h / -10 °C View Scheme

1: aq. MH3 / tetrahydrofuran / 0.75 h / -10 °C 2: 85 percent / Lawesson's reagent / CH2Cl2 / 16 h / Ambient temperature 3: KHCO3 / 1,2-dimethoxy-ethane / 16 h / -15 °C 4: TFAA, 2,6-lutidine / 1,2-dimethoxy-ethane / 0.5 h / -10 °C View Scheme

1: lithium hydroxide hydrate / water; methanol / |Inert atmosphere 2: ammonia / tetrahydrofuran; water / |Inert atmosphere 3: trifluoroacetic anhydride; triethylamine / dichloromethane / |Inert atmosphere View Scheme

potassium hydroxide in tetrahydrofuran; water T=20°C; 1 h;

methoxybenzene; trifluoroacetic acid in dichloromethane T=20°C; Inert atmosphere;