Patent ID: 7220855
Filing Date: 2007-05-22
Classification: C07H

Abstract:
1. A two-step process for producing methylcobalamin (V), comprising the sequential steps of A) and B): A) reducing cyanocobalamin (I) or hydroxocobalamin (II) represented by the following formula in the presence of a reducing agent (III) that is sodium borohydride, and B) methylating the reductant by adding a water-soluble methylating agent (IV) R 2 =CN: Cyanocobalamin (I) R 2 =OH: Hydroxocobalamin (II) R 2 =CH: Methylcobalamin (V) wherein the water-soluble methylating agent (IV) is a trimethylsulfur derivative (VI) represented by the following formula: wherein X is a halogen atom or a methoxysulfonyloxy group, and n is 0 or 1; and wherein the amount of the trimethylsulfur derivative (VI) added is from 1.0 to 5.0 equivalents to cyanocobalamin (I) or hydroxocobalamin (II).