Pyridine → 5-Bromo-4-hydroxy-6-methylpyridine-3-carboxylic acid

HRID 2271117Notes

Reaction equation

HRID 2271117 reaction equation
[CH3:1][C:2]1[NH:8][CH:7]=[C:6]([C:9]([OH:11])=[O:10])[C:4](=[O:5])[CH:3]=1.N1C=CC=CC=1.[Br:18]Br>C(O)(=O)C>[Br:18][C:3]1[C:4](=[O:5])[C:6]([C:9]([OH:11])=[O:10])=[CH:7][NH:8][C:2]=1[CH3:1]

Participants

5

Reactant 3

HCID 1049PyridineHCID 24408BromineHCID 107020144-Hydroxy-6-methyl-nicotinic acid

Product 1

HCID 183299675-Bromo-4-hydroxy-6-methylpyridine-3-carboxylic acidYield 70%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

To 6-methyl-4-(1H)-pyridone-3-carboxylic acid (prepared according to the procedure described in J. Org. Chem., 1972, 37, 1145-1148) (10.0 g, 65.4 mmol) and dry pyridine (5.2 ml) in acetic acid (200 ml) at 100° C. was added bromine (14.6 g, 91.5 mmol) in acetic acid (30 ml) dropwise over 1 hour. Heating was continued for 2 hours then cooled to room temperature. The precipitate which formed on cooling was collected by filtration, and washed with methanol to give the product as a cream coloured solid (10.62 g, 70%). 1H NMR (250 MHz, DMSO-d6) δ14.75 (1H, br s), 13.45 (1H. br s), 8.58 (1H, s), 2.53 (3H, s); MS (ES+) m/z 232/234 MH]+, 214/216 [(M-(H2O))H]+.

Workup

  1. temperatureHeating
  2. customThe precipitate which formed
  3. temperatureon cooling
  4. filtrationwas collected by filtration
  5. washwashed with methanol

Sources & evidence

ORD record
ord-6e059b17d4494ab19e1c18000ef28b8c
Source dataset
uspto-grants-2001_12
Patent number
US06333336B1

Reaction notes

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