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. A further amount of 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), 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-c2e513c67fd54d508ec713b7a5dc83c9

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266896B2