Water → 6-Amino-3-bromo-2-hydroxybenzoic acid

Temperature

100 °C

A mixture of methyl 6-amino-3-bromo-2-hydroxybenzoate (prepared according to Wang et al, Bioorg Med Chem Lett, 2007, 17, 2817, 5.41 g) and lithium hydroxide monohydrate (9.23 g) was suspended in dioxane (100 mL) and water (100 mL) and heated at 80° C. overnight. The temperature was then increased to 100° C. for 4 hours. Further lithium hydroxide monohydrate (4.61 g) was added and the reaction mixture was heated at 100° C. for a further 1 hour. After cooling, the mixture was concentrated in vacuo and the residue was acidified to pH3 with formic acid and extracted with ethyl acetate. The organic layer was dried (MgSO4) and filtered and the filtrate was concentrated in vacuo to give 6-amino-3-bromo-2-hydroxybenzoic acid (6.22 g) as a black/grey solid.

1. temperaturethe reaction mixture was heated at 100° C. for a further 1 hour
2. temperatureAfter cooling
3. concentrationthe mixture was concentrated in vacuo
4. extractionextracted with ethyl acetate
5. dry with materialThe organic layer was dried (MgSO4)
6. filtrationfiltered
7. concentrationthe filtrate was concentrated in vacuo

ORD record

ord-b401202c72b0434894b443837a9c42f1

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09187494B2