1.1: oxalyl chloride; N,N-dimethylformamide / CH2Cl2 / 1.5 h / 20 °C 1.2: 100 percent / ammonia gas / CH2Cl2 / 2 h / 0 °C 2.1: 1,2-dichloro-ethane / 4 h / Heating 2.2: 90 percent / dioxane / 4 h / 0 - 20 °C 3.1: 84 percent / potassium bis(trimethylsilyl)amide; 18-crown-6 / tetrahydrofuran; toluene / 1.5 h / Heating View Scheme

1: With oxalyl dichloride; N,N-dimethyl-formamide in dichloromethane T=20°C; 1.5 h; 2: With ammonia in dichloromethane T=0°C; 2 h;

1: oxalyl chloride / dimethylformamide / 24 h / 20 °C 2: 4.30 g / CH2Cl2 / 48 h / 20 °C 3: thionyl chloride / CHCl3 / 20 °C 4: 2.56 g / sodium hydroxide / H2O / 20 °C / pH 8 View Scheme

1: oxalyl chloride / dimethylformamide / 24 h / 20 °C 2: 4.30 g / CH2Cl2 / 48 h / 20 °C View Scheme

sodium ethoxide in benzene (N2); organic ligand, sodium ethoxide added in benzene to a Schlenk flask; stirred for 10 min; trimethyltin chloride added to mixt. (in 1:1:1 molar ratio); stirred for 12 h at 40°C; filtered; filtrate gradually evapd.; recrystallized from ether-petroleum; elem. anal.;

sodium ethoxide in benzene (N2); organic ligand, sodium ethoxide added in benzene to a Schlenk flask; stirred for 10 min; tri-n-butyltin chloride added to mixt. (in 1:1:1 molar ratio); stirred for 12 h at 40°C; filtered; filtrate gradually evapd.; recrystallized from ether-petroleum; elem. anal.;

1.1: thionyl chloride; sodium chloride / ethyl acetate / 4 h / |Reflux; |Inert atmosphere 2.1: magnesium chloride / ethyl acetate / 0.5 h / 20 °C / |Inert atmosphere 2.2: 0.5 h / 20 °C / |Inert atmosphere 2.3: 2 h / |Inert atmosphere; |Reflux 3.1: potassium hydroxide; tetrabutylammomium bromide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 3.2: 16 h / 0 - 20 °C / |Inert atmosphere 3.3: 3 h / |Inert atmosphere 4.1: potassium tert-butylate / toluene / 16 h / |Inert atmosphere; |Reflux 5.1: Oxonereg; / water; methanol / 3 h / 55 - 60 °C 6.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 6.2: pH Ca. 1 - 2 7.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C View Scheme

1.1: thionyl chloride; sodium chloride / ethyl acetate / 4 h / |Reflux; |Inert atmosphere 2.1: magnesium chloride / ethyl acetate / 0.5 h / 20 °C / |Inert atmosphere 2.2: 0.5 h / 20 °C / |Inert atmosphere 2.3: 2 h / |Inert atmosphere; |Reflux 3.1: potassium hydroxide; tetrabutylammomium bromide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 3.2: 16 h / 0 - 20 °C / |Inert atmosphere 3.3: 3 h / |Inert atmosphere 4.1: potassium tert-butylate / toluene / 16 h / |Inert atmosphere; |Reflux 5.1: Oxonereg; / water; methanol / 3 h / 55 - 60 °C 6.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 6.2: pH Ca. 1 - 2 7.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C 8.1: N,N-dimethyl acetamide / 18 h / 90 °C / |Inert atmosphere 9.1: dichloromethane / 4 h / 20 °C / |Inert atmosphere 10.1: tert.-butylnitrite; copper(ll) bromide / acetonitrile / 0.17 h / 67 °C / |Inert atmosphere View Scheme

Multi-step reaction with 3 steps 1: oxalyl chloride, DMF / CH2Cl2 / 18 h / Ambient temperature2: 1.) n-BuLi, 2,2'-bipyridyl / 1.) THF, hexane, from -20 deg C to -5 deg C, 2.) THF, hexane, -30 deg C, 2 h3: acetic anhydride / 22 h / Heating