As a model compound in methyl transfer process from N^5-methyltetra- hydrofolate(III) to methionine synthase, 2-amino-4-hydroxy-5, 5, 6- trimethyl-5, 6, 7, 8-tetrahydropyrido [3, 2-d] pyrimidinium iodide 8 was synthesized from 5-aminouacil through seven stepsof reactions. Compound 8 reacts with [Co(I)(dmgH)~2Py] to give CH~3-Co(dmgH)~2Py. The structures of all compounds were characterized by elemental analysis, UV, ^1H NMR and MS.

Key words: SYNTHESIS, SYNTHETASE, PYRIDINO-, CATALYTIC MECHANISM, COENZYME, PYRIMIDINE P, METHYL TRANSFERASE, METHIONINE