ziconium(IV) oxychloride octahydrate T=120°C; 2.5 h; Neat (no solvent);

sodium acetate; triphenylphosphine; bis-triphenylphosphine-palladium(II) chloride in N,N-dimethyl-formamide T=80°C; P=15200 Torr; 8 h;

trifluorormethanesulfonic acid T=25°C; 6 h;

1: lithium ethanolate; 2-Carboxybenzaldehyde in tetrahydrofuran 2: [(1-phenyl-1-ethenyl)oxy]trimethylsilane in N,N-dimethyl-formamide T=20°C; 2 h; 3: With hydrogenchloride in tetrahydrofuran T=20°C;

1.1: n-butyllithium / tetrahydrofuran / -78 °C 1.2: 0 °C 2.1: dichloromethane / 15 h / 20 °C / |Inert atmosphere 3.1: 2-mesityl-2,5,6,7-tetrahydropyrrolo[2,1-c][1,2,4]triazol-4-ium chloride; triethylamine / toluene / 10 h / 25 °C View Scheme

1.1: toluene-4-sulfonic acid / benzene / |Reflux 2.1: n-butyllithium / tetrahydrofuran / -78 °C 2.2: 0 °C 3.1: dichloromethane / 15 h / 20 °C / |Inert atmosphere 4.1: 2-mesityl-2,5,6,7-tetrahydropyrrolo[2,1-c][1,2,4]triazol-4-ium chloride; triethylamine / toluene / 10 h / 25 °C View Scheme

1: dichloromethane / 15 h / 20 °C / |Inert atmosphere 2: 2-mesityl-2,5,6,7-tetrahydropyrrolo[2,1-c][1,2,4]triazol-4-ium chloride; triethylamine / toluene / 10 h / 25 °C View Scheme

(i) Br2, benzene, (ii) NH2OH*HCl, NaOAc, AcOH; Multistep reaction;