sodium hydrogencarbonate; hydroxylamine-o-sulphonic acid in tetrahydrofuran T=20°C;

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: magnesium chloride / ethyl acetate / 0.5 h / 20 °C / |Inert atmosphere 1.2: 0.5 h / 20 °C / |Inert atmosphere 1.3: 2 h / |Inert atmosphere; |Reflux 2.1: potassium hydroxide; tetrabutylammomium bromide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 2.2: 16 h / 0 - 20 °C / |Inert atmosphere 2.3: 3 h / |Inert atmosphere 3.1: potassium tert-butylate / toluene / 16 h / |Inert atmosphere; |Reflux 4.1: Oxonereg; / water; methanol / 3 h / 55 - 60 °C 5.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 5.2: pH Ca. 1 - 2 6.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C View Scheme

1.1: potassium hydroxide; tetrabutylammomium bromide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 1.2: 16 h / 0 - 20 °C / |Inert atmosphere 1.3: 3 h / |Inert atmosphere 2.1: potassium tert-butylate / toluene / 16 h / |Inert atmosphere; |Reflux 3.1: Oxonereg; / water; methanol / 3 h / 55 - 60 °C 4.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 4.2: pH Ca. 1 - 2 5.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C View Scheme

1.1: Oxonereg; / water; methanol / 3 h / 55 - 60 °C 2.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 2.2: pH Ca. 1 - 2 3.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C View Scheme

1.1: sodium hydrogen sulfide hydrate / N,N-dimethyl-formamide / 5 h / 20 °C / |Inert atmosphere 1.2: pH Ca. 1 - 2 2.1: potassium phosphate; hydroxylamine-o-sulphonic acid / water; tetrahydrofuran / 0 - 20 °C View Scheme

1: N,N-dimethyl-acetamide / 24 h / 90 °C 2: CH2Cl2 / 6 h / 20 °C 3: 4.1 g / t-butyl nitrite; cupric bromide / acetonitrile / 0.5 h / Heating View Scheme