pyridine in dichloromethane T=5 - 15°C; 0.333333 h;

Na; MeOH in tetrahydrofuran; acetonitrile simultaneous addn. of solns. of Ni-complex and Na/MeOH to boiling MeCN (6 h), refluxing (36 h, pptn.), cooling to room temp.; chromy., crystn. (MeCN/MeOH); elem.anal.;