Mephenesin, oxidation

Potassium bromate can also be employed as an oxidizing agent in the assay of a number of pharmaceutical substances, namely mephenesin, phenol, and sodium salicylate. This particular method solely depends upon the formation of iodine monobromide (IBr) in relatively higher concentration of hydrochloric acid solution. 

Theory Mephenesin undergoes oxidation with bromine to yield a dibromo derivative as expressed in the following equation ... 

Since DPA does not originally contain a nitrogen atom in its chemical structure, a transamination reaction must occur for the formation of this compound. As we have found that 2-n-propyl-3 -oxopentanoic acid was formed as an intermediate of DPA by S " -oxidation, transamination may take place between some amino acid and 2-n-propyl-3-oxopentanoic acid to form 2-n-propyl-3-amino-pentanoic acid. This amino acid is probably N-acetylated by acetyl--CoA (Fig. 2). The mechanism seems to be similar to that for Mephenesin which involves a preliminary oxidation followed by transamination and N-acetylation (6). ... 

Mephenesin, 3-( -tolyloxy)- ,2-propanediol, undergoes hydroxylation on the aromatic ring (1) and oxidation of the C -alcoholic hydroxyl group to form 3- -tolyloxylactic acid, which is the major metabolite of Mephenesin (2,3). 

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