in tetrahydrofuran; water Schlenk techniques; addn. of aq. NaOH (more than 70 equiv.) to soln. of Fe complex in THF, stirring overnight at room temp.;

in methanol; water Schlenk techniques; addn. of aq. soln. of NaOH (more than 30 equiv.) to soln. of Fe complex in MeOH, stirring at room temp., after 1.5 h addn. of water and 1 M HCl;