Method of synthesis of the sodium salt of N-acetyl-L-cysteinylcobalamin

摘要

The invention provides a method for preparing the sodium salt of the novel thiol derivative of vitamin B₁₂, N-acetyl-L-cysteinylcobalamin (Na[NACCbl]). The method involves carrying out the reaction in aqueous solvent with a relatively small excess of ligand reactant, specifically from one to less than four molar equivalents. The cobalamin derivative formed is precipitated from the aqueous solvent, preferably by the addition of a precipitate inducing solvent. This provides a product in acceptable purity without the need for an additional chromatographic purification step.