Dimethyl malate

67-56-1

97-67-6

617-55-0

Thionyl chloride (117 g, 0.98 mol) was slowly added dropwise to a methanol (400 mL) solution of L-malic acid (59.9 g, 0.45 mol) in an ice-water bath. After the dropwise addition, the reaction mixture was stirred at room temperature (25 °C) for overnight reaction. The progress of the reaction was monitored by thin layer chromatography (TLC, unfolding agent ratio ethyl acetate: methanol = 10:1). After completion of the reaction, the solvent was evaporated under reduced pressure. Saturated sodium bicarbonate solution (200 mL) was added to the residue and the aqueous phase was extracted with ethyl acetate (3 x 150 mL). The organic phases were combined, washed sequentially with water (3×80 mL), saturated saline (3×80 mL) and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure to give dimethyl L-malate as a light yellow oil in 98% yield (71.5 g, 0.44 mol).