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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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

Herkunft & Nachweise