sodium tetrahydroborate; ethanol T=0 - 20°C; 21 h;

1: 2,5-diiodopyridine With n-butyllithium in hexane; toluene T=-78°C; 2.5 h; Inert atmosphere; 2: N,N-dimethyl-formamide in hexane; toluene T=-78 - -10°C; 1 h; Inert atmosphere; 3: With sodium tetrahydroborate in hexane; toluene T=0°C; 0.5 h;

1: With n-butyllithium in hexane; N,N-dimethyl-formamide; toluene T=-78°C; 3.5 h; Inert atmosphere; 2: With sodium tetrahydroborate in hexane; N,N-dimethyl-formamide; toluene T=-10 - 0°C; 0.5 h; 3: With ammonium chloride in hexane; water; N,N-dimethyl-formamide; toluene T=0 - 20°C;

manganese(IV) oxide in dichloromethane T=20°C; 20 h;