Patent ID: 8680329

Claim:
A process of preparation of α-ketoglutaric acid for mass production of L-arginine α-ketoglutarate 1:1 and 2:1 comprising the steps of: (a) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain Dimethyl 2,2-dichloroglutarate; (b) reacting the dimethyl 2,2-dichloroglutarate from step (a) with hydroxide solution to obtain crude α-ketoglutaric acid aqueous solution; (c) purifying the crude α-ketoglutaric acid aqueous solution to obtain purified α-ketoglutaric acid aqueous solution; (d) adjusting the concentration of the purified α-ketoglutaric acid aqueous solution by adding water; (e.1′) setting the concentration of the purified α-ketoglutaric acid aqueous solution by adding water; (e.2′) adding a quantity of solid L-arginine to the purified α-ketoglutaric acid aqueous solution, wherein the quantity of the solid L-arginine is equal to two equivalent mole of the purified α-ketoglutaric acid aqueous solution; (e.3′) obtaining a resulting L-arginine α-ketoglutarate 2:1 solution from step (e.2), wherein the pH of the resulting L-arginine α-ketoglutarate 2:1 solution is approximately 6.5˜7; and (e.4′) obtaining a final product of L-arginine α-ketoglutarate 2:1 from step (e.3) through spray drying, wherein the yield of the final product is approximately 97%.