Description
Methyl lactate is a compound with many uses. It can be used as a solvent, as a starting material for the manufacture of polyiactic acid, or as a starting material for numerous other reactions. For example, it can be used as intermediate in lactic acid purification, and as building block in the synthesis of chiral components, e.g., pesticides, and as a starting material for lactide manufacture.
Chemical Properties
Methyl lactate is a colorless transparent liquid. It is soluble/miscible in water, acetone, ethyl alcohol, and other organic solvents. It is used as a cellulose acetate solvent.
Uses
Methyl lactate is used as a solvent for nitrocellulose, cellulase acetate, cellulase acetobutyrote and cellulase acetaprapionate. It is used in the manufacture of lacquers and dopes where it contributes high tolerance for diluents, good flaw and blush resistance.
Definition
ChEBI: Methyl lactate is a lactate ester resulting from the formal condensation of the carboxy group of 2-hydroxypropanoic acid with methanol. It has a role as a metabolite. It is a lactate ester and a methyl ester.
Application
One important use of methyl lactate is use in the manufacture of methyl acrylate, which is a starting material for the manufacture of acrylate polymers. Additionally methyl acrylate is a suitable starting material for acrylic acid and other esters like ethyl acrylate and butyl acrylate.
Preparation
Bringing an aqueous liquid comprising lactic acid, methanol, and at least 5 wt.% of a dissolved chloride salt selected from magnesium chloride, calcium chloride, and zinc chloride to reaction conditions, thereby obtaining methyl lactate, wherein an extractant is provided to the reaction mixture before, during, and/or after formation of methyl lactate,Subjecting the reaction mixture to a liquid-liquid separation step wherein an organic phase comprising methyl lactate and extractant is separated from an aqueous phase comprising dissolved chloride salt.The wt.% is calculated on the weight of the aqueous liquid. It has been found that the process according to the invention makes it possible to manufacture methyl lactate efficiently and in high yield.
Hazard
Moderate fire risk.
Safety Profile
Methyl lactate has been classed as non-irritant to the eyes of guinea pigs.
The estimated average lethal dose for the female rat following i.p. injection of methyl lactate was >2000 mg/kg body weight. Observations included narcosis, respiratory distress and peritoneal adhesions. The estimated non toxic dose and estimated maximum dose without gross lesions at necropsy was 500 mg/kg body weight.
Synthesis
Methyl lactate is prepared by the esterification of methyl alcohol with lactic acid.
Purification Methods
Methyl lactate is easily hydrolyzed and often contains impurities such as free lactic acid, methanol and water. Free acid can be removed by washing after neutralization with alkali. Moisture can be removed by azeotropic distillation of an azeotropic mixture with benzene. Then, it was purified by distillation under reduced pressure. Since calcium chloride and the like form molecular compounds with methyl lactate, they cannot be used as desiccants. When the methyl lactate is mixed with water, it can be extracted and recovered with benzene, ether, etc.
