Isp Investments Inc.

Jonathan Caudill

Satish C Nigam

Mark J Cooney

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.

Pharmaceutically acceptable inorganic and organic salts of 5-methylpyrazine-2-carboxylic acid-4-oxide

Methods for the preparation of pharmaceutically acceptable salts of 5-methylpyrazine-carboxylic acid-4-oxide by using the oxidizing agent OXONE&#xae; for the N-oxidation of Cmethylpyrazinecarboxylic acid esters. The pharmaceutically acceptable salts are then formed by the saponification of the esters followed by alcohol precipitation.

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Ashville, OH, United States of America

Jonathan Caudill