Hydrochloric Acid → (2R)-2-hydroxy-2-(2-methoxyphenyl)acetic acid

(R)-mandelic acid (4.678 g, 30.75 mmol) was dissolved in 6M NaOH (50 mL, 300 mmol) and dimethyl sulfate (14.6 mL, 154 mmol) was added over 1 hr so that the temperature stayed at 50° C. After another hr of stirring, H2O (50 mL) was added, and the solution was acidified to pH 1 with 12M HCl. The mixture was saturated with NaCl, extracted with EtOAc (3×100 mL), and the extracts dried with Na2SO4. After filtration and evaporation under reduced pressure, the solid was pulverized, refluxed in hexanes (100 mL) for 15 min and hot filtered. The insoluble (R)-mandelic acid (2.71 g, 58%) was recovered, and the hexanes evaporated under reduced pressure to give (R)-2-methoxy-mandelic acid, (R)-3 (1.91 g, 37%) which was used directly in the next step.

1. customstayed at 50° C
2. extractionextracted with EtOAc (3×100 mL)
3. dry with materialthe extracts dried with Na2SO4
4. filtrationAfter filtration and evaporation under reduced pressure
5. temperaturerefluxed in hexanes (100 mL) for 15 min
6. customThe insoluble (R)-mandelic acid (2.71 g, 58%) was recovered
7. customthe hexanes evaporated under reduced pressure

ORD record

ord-e2ee77db80fa485f8c4d975810dcfc68

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08148128B2