Pharmaceutically acceptable inorganic and organic salts of 5-methylpyrazine-2-carboxylic acid-4-oxide
申请人:Cooney Mark
公开号:US20050261312A1
公开(公告)日:2005-11-24
Methods for the preparation of pharmaceutically acceptable organic or inorganic salts of 5-methylpyrazinecarboxylic acid-4-oxide esters including tris(hydroxymethyl)aminomethanol, N,N-dimethylethanolamine, N-methyl-D-glucamine, L-Lysine, L-arginine, Na, K, Ca and Mg. The esters of 5-methylpyrazinecarboxylic acid-4-oxide are oxidized in aqueous hydrogen peroxide at a pH of 2.5 to 7 in the presence of a catalyst selected from the group consisting of sodium tungstate, tungstic acid and ammonium heptamolybdate. The salts are formed by saponification of the esters followed by alcohol precipitation, or by reaction with a metal trimethylsilanoate, or by the reaction of organic bases with the saponified acids.