METHOD OF SYNTHESIS OF 2-KETO-L-GULONIC ACID Russian patent published in 2002 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to a method of synthesis of 2-keto-L-gulonic acid that is an intermediate product in vitamin C synthesis by oxidation of L-sorbose in the presence of platinum-containing catalyst in an aqueous-alkaline medium with equimolar content of NaHCO₃, under atmosphere pressure, intensive stirring and bubbling of pure oxygen as an oxidizing agent at the rate 440-460 ml/min. Platinum-polymeric catalyst is synthesized by addition of H₂PtCl₆•6H₂O in the amount 0.005 mole/l to an aqueous solution of block-polymer, polyethylene oxide-poly-2(4)-vinylpyridine containing 0.017-0.0175 mole of 2(4)-vinylpyridinum groups/l and 0.06-0.065 mole of polyethylene oxide groups/l followed by reduction with NaBH₄ taken in five-fold mole excess to yield metal nanoparticles stabilized in polyethylene oxide-poly-2(4)-vinylpyridine solution and the following application on Al₂O₃. Catalyst is used in concentration 25-45 g/l mainly being platinum content in catalyst is 2-3%. Method provides to increase the yield of 2-keto-L-gulonic acid up to 99% and cyclic use of catalyst. EFFECT: increased yield, decreased cost of catalyst. 8 cl, 1 tbl, 1 dwg, 3 ex