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-Eintrag

ord-2ee21c3b4c314f159eb4f45411a367d3

Quelldatensatz

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08357524B2