1.1: bis-(2-amino-phenyl)-disulphide; triphenylphosphine / dimethyl sulfoxide / 20 °C / |Inert atmosphere 2.1: tris(tetra-n-butylammonium)hydrogen diphosphate; 4,5-dicyanoimidazole / N,N-dimethyl-formamide / 6 h / 20 °C / |Inert atmosphere 2.2: |Inert atmosphere View Scheme

1: triethylamine; 2,2'-dithiodipyridine; triphenylphosphine / dimethylformamide / 2 h / 20 °C 2: 95 percent / tributylammonium orthophosphate; zinc chloride / dimethylformamide / 3 h / 20 °C View Scheme

1.1: bis-(2-amino-phenyl)-disulphide; triphenylphosphine / dimethyl sulfoxide / 20 °C / |Inert atmosphere 2.1: tris(tetra-n-butylammonium)hydrogen diphosphate; 4,5-dicyanoimidazole / N,N-dimethyl-formamide / 6 h / 20 °C / |Inert atmosphere 2.2: |Inert atmosphere View Scheme

1.1: bis-(2-amino-phenyl)-disulphide; triphenylphosphine / dimethyl sulfoxide / 20 °C / |Inert atmosphere 2.1: tris(tetra-n-butylammonium)hydrogen diphosphate; 4,5-dicyanoimidazole / N,N-dimethyl-formamide / 6 h / 20 °C / |Inert atmosphere 2.2: |Inert atmosphere View Scheme