Water → 3-Bromo-6-acetamidopyridine-2-carboxylic acid

Temperature

90 °C

To a solution of N-(5-bromo-6-methyl-pyridin-2-yl)-acetamide 48.46 g in pyridine 250 ml was added water 250 ml and the mixture warmed to 90° C. and potassium carbonate 2.2 g was added. Potassium permanganate was added portionwise over 10 h and the mixture allowed to cool slowly overnight. The reaction mixture was re-heated to 90° C. for 2 h, cooled slightly and filtered to remove manganese dioxide. The filtrate was evaporated in vacuo and the residue partitioned between water 1 L and ethyl acetate 500 ml. The aqueous solution was washed with ethyl acetate. The organic solutions were combined, washed with brine, dried MgSO4 and evaporated in vacuo to recover unchanged starting materials 12.6 g. The aqueous solution was acidified with concentrated hydrochloric acid (circa 80 ml) and the solid product filtered off, washed with a minimum of water, sucked dry and then dried at 80° C. (vac) to give 6-acetylamino-3-bromo-pyridine-2-carboxylic acid 24.9 g

1. temperatureto cool slowly overnight
2. temperatureThe reaction mixture was re-heated to 90° C. for 2 h
3. temperaturecooled slightly
4. filtrationfiltered
5. customto remove manganese dioxide
6. customThe filtrate was evaporated in vacuo
7. customthe residue partitioned between water 1 L and ethyl acetate 500 ml
8. washThe aqueous solution was washed with ethyl acetate
9. washwashed with brine, dried MgSO4
10. customevaporated in vacuo
11. customto recover unchanged
12. filtrationthe solid product filtered off
13. washwashed with a minimum of water
14. customsucked dry
15. customdried at 80° C. (vac)

ORD record

ord-f06965780ec74d4d9f5a69f09679b26e

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07893077B2