METHOD OF PREPARING DIACETONE-α-SORBOSE Russian patent published in 1997 - IPC

FIELD: chemical industry, more particularly use as intermediate in manufacture of ascorbic acid (vitamin C). SUBSTANCE: claimed method comprises reacting α-sorbose and acetone in the presence of sulfuric acid or oleum, subsequently neutralizing reaction mixture with aqueous alkali to pH of 9.5-12 and distilling acetone. After distillation of acetone, aqueous solution of diacetone-α-sorbose is heated at 80-90 C for 30-60 minutes, then cooled to 60-84 C, treated with toluene at 1:0.25-0.9 ratio respectively, followed by reextraction of diacetone-α-sorbose from toluene solution having pH of 4-6.6. The method makes it possible to obtain more efficiently diacetone-α- sorbose, improve its quality due to reducing formation of by-products. EFFECT: more efficient preparation method. 1 tbl