PURPOSE: To obtain a lactic ester for obtaining lactic acid useful for food, industry, etc. in high yield, by reacting lactonitrile with water and sulfuric acid, and esterifying the resultant reaction product with an alcohol and water.
CONSTITUTION: One mole lactonitrile is reacted with 0.8W1.1mol as water and sulfuric acid at 65W75°C to give a reaction product consisting of a lactamide sulfate essentially without depositing ammonium bisulfate. The resultant reaction product is then esterified with an excess of an alcohol and water at a molar ratio of 0.5W2.0mol, preferably 1.0W1.8mol, based on one mole lactonitrile at 100W140°C, and the formed lactic ester is simultaneously distilled.
EFFECT: The hydrolysis and the esterifying reaction separately carried out to reduce the basic unit, energy cost in the purification of the ester, and corrosion of apparatuses and improve the operating efficiency.
DOUSONO TETSUO
MUNEMURA HIDEKAZU
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