in ethanol on react. of methyl cobalamine with soln. of 2,3-dichloro-5,6-dicyano-benzoquinone-(1,4) at darkness, 30min;;

sodium tetrahydroborate; cobalt(II) chloride in water; butanone T=15 - 40°C;

1: cyanocobalamin With sodium tetrahydroborate; cobalt(II) chloride in water; butanone T=30 - 50°C; 1.66667 - 2.5 h; 2: trimethyloxosulfonium bromide in water; butanone T=15 - 50°C;

sodium tetrahydroborate; cobalt(II) chloride in water; butanone T=15 - 40°C;