Nitric Acid → 2-Methyl-6-nitro-3-pyridinol

HRID 2244417Notes

Reaction equation

HRID 2244417 reaction equation
[OH:1][C:2]1[C:3]([CH3:8])=[N:4][CH:5]=[CH:6][CH:7]=1.S(=O)(=O)(O)O.[N+:14]([O-])([OH:16])=[O:15].[OH-].[NH4+]>>[CH3:8][C:3]1[C:2]([OH:1])=[CH:7][CH:6]=[C:5]([N+:14]([O-:16])=[O:15])[N:4]=1

Participants

5

Reactant 4

HCID 944Nitric AcidHCID 1118Sulfuric Acid2×HCID 14923Ammonium HydroxideHCID 707192-Methylpyridin-3-ol

Product 1

HCID 217660202-Methyl-6-nitro-3-pyridinolYield 10%

Procedure

While maintaining a temperature of 0-5° C. with external ice cooling, 3-hydroxy-2-methyl pyridine (10.00 g, 91.63 mmol) was added gradually to concentrated sulfuric acid (65.00 ml). A mixture of concentrated sulfuric acid (8.50 ml) and nitric acid (6.50 g, 103.16 mmol) was added over 2 h. The resulting mixture was poured onto ice. Addition of a few milliliters of saturated ammonium hydroxide caused precipitation of crude 2-methyl-6-nitro-pyridin-3-ol. This was collected by filtration and recrystallized from methanol/water to yield pure 2-methyl-6-nitro-pyridin-3-ol (1.37 g, 10%). Basification of the mother liquors to pH 3-4 triggered precipitation of the isomeric 2-methyl-4-nitro-pyridin-3-ol (major component), which was discarded.

Workup

  1. additionwas added over 2 h
  2. additionThe resulting mixture was poured onto ice
  3. customprecipitation of crude 2-methyl-6-nitro-pyridin-3-ol
  4. filtrationThis was collected by filtration
  5. customrecrystallized from methanol/water

Sources & evidence

ORD record
ord-bccec5de3b7c435f9026563d81c91850
Source dataset
uspto-grants-2010_03
Patent number
US07678815B2

Reaction notes

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