Hydrochloric Acid → 4-Hydroxy-2-methoxybenzoic acid

Temperature

40 °C

To a solution of the methyl 2-methoxy-4-hydroxybenzoate (27 g, 147 mmol) from Step 3 above in MeOH (250 mL) was added 2N sodium hydroxide (147 mL, 2 eq) and the reaction was stirred for 5 hours at 40° C. The reaction was brought to pH 4 with the addition of 6N HCl and the solvent was reduced to one-third volume under reduced pressure. The aqueous mixture was extracted with methylene chloride (5×300 mL) and the combined organic phases were washed with water, brine, and dried over MgSO4. The solution was filtered and the solvent removed under reduced pressure to give a solid which was suspended in ether and filtered. 2-Methoxy-4-hydroxybenzoic acid was obtained in 80% yield.

1. extractionThe aqueous mixture was extracted with methylene chloride (5×300 mL)
2. washthe combined organic phases were washed with water, brine
3. dry with materialdried over MgSO4
4. filtrationThe solution was filtered
5. customthe solvent removed under reduced pressure
6. customto give a solid which
7. filtrationfiltered

ORD record

ord-13af8573225648cfaa3124ed24125770

Source dataset

uspto-grants-1997_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05665719