4-Hydroxybenzoic Acid → Methylparaben

To a solution of 4-hydroxybenzoic acid (138 g, 1.00 mol) in methanol (1000 mL) was added concentrated sulfuric acid (20 mL), then the reaction heated at reflux for 20 h. The reaction mixture was concentrated to one half the original volume under reduced pressure then partitioned with ethyl acetate (1000 mL) and water (1000 mL). The organic layer was washed with 1 N aqueous sodium hydroxide (2×300 mL), water (300 mL), brine (300 mL) then dried (MgSO4). The solvent was removed under reduced pressure to give the ester as a white solid (106.62 g, 70%) after drying under vacuum at ambient temperature.

1. temperaturethe reaction heated
2. temperatureat reflux for 20 h
3. concentrationThe reaction mixture was concentrated to one half the original volume under reduced pressure
4. customthen partitioned with ethyl acetate (1000 mL) and water (1000 mL)
5. washThe organic layer was washed with 1 N aqueous sodium hydroxide (2×300 mL), water (300 mL), brine (300 mL)
6. dry with materialthen dried (MgSO4)
7. customThe solvent was removed under reduced pressure

ORD record

ord-9942795fe27140fa8cccf1e84bc51c5f

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06541499B1