Synthesis of levomethadone hydrochloride

A method for synthesizing levomethadone hydrochloride, comprising:

• producing (R)-2-(dimethylamino)propan-1-ol by reducing N,N-dimethyl-D-alanine using borax, reducing the N,N-dimethyl-D-alanine using the borax comprising:
• forming a plurality of complexes in water by adding nickel chloride hexahydrate (NiCl2.6H2O) to a solution of the N, N-dimethyl-D-alanine with a molar ratio of NiCl2.6H2O to the N, N-dimethyl-D-alanine between 3.5 and 4.5, the plurality of complexes comprising the N, N-dimethyl-D-alanine and the NiCl2. 6H2O;
• and
• mixing the plurality of complexes with water and the borax at room temperature, comprising:
• forming a solution by adding the plurality of complexes to the water;
• and
• adding the borax with a concentration between 100 mM and 160 mM to the solution;
• forming (R)-1-chloro-N,N-dimethylpropane-2-amine hydrochloride by chlorinating the (R)-2-(dimethylamino)propan-1-ol;
• synthesizing levomethadone nitrile hydrochloride by mixing the (R)-1-chloro-N,N-dimethylpropane-2-amine and diphenylacetonitrile with potassium t-butoxide;
• and
• producing levomethadone hydrochloride by exposing the levomethadone nitrile hydrochloride to a Grignard reagent.