Nitric Acid → Pyridine, 2,5-dimethyl-4-nitro-, 1-oxide

HRID 703175Notes

Reaction equation

HRID 703175 reaction equation
[N+:1]([O-:4])(O)=[O:2].[CH3:5][C:6]1[CH:11]=[CH:10][C:9]([CH3:12])=[CH:8][N+:7]=1[O-:13].[OH-].[Na+]>S(=O)(=O)(O)O>[CH3:5][C:6]1[CH:11]=[C:10]([N+:1]([O-:4])=[O:2])[C:9]([CH3:12])=[CH:8][N+:7]=1[O-:13]

Participants

5

Reactant 3

HCID 944Nitric AcidHCID 14798Sodium HydroxideHCID 5717732,5-Dimethylpyridin-1-ium-1-olate

Product 1

HCID 146707Pyridine, 2,5-dimethyl-4-nitro-, 1-oxide

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

260 ml of fuming nitric acid (d =1.5) were added dropwise to 840 ml of concentrated sulphur-ic acid while cooling. 348,2 g of 2,5-dimethy1pyridine 1-oxide were subsequently added portionwise at 0-5° . The mixture was stirred at room temperature for 1 hour, then heated to 90° within 3 hours, left at this temperature overnight and, after cooling, poured on to 6 kg of ice. The mixture was adjusted to pH 3 with concentrated sodium hydroxide solution and extracted three times with 2 1 of methylene chloride. The combined organic phases were washed with 4 1 of water, dried over sodium sulfate and evaporated in vacuo. The residue was crystallized from methylene chloride/petroleum ether and there was obtained 2,5-dimethyl-4-nitropyridine 1-oxide of melting point 142-144° .

Workup

  1. temperaturewhile cooling
  2. temperatureheated to 90° within 3 hours
  3. waitleft at this temperature overnight
  4. temperatureafter cooling
  5. extractionextracted three times with 2 1 of methylene chloride
  6. washThe combined organic phases were washed with 4 1 of water
  7. dry with materialdried over sodium sulfate
  8. customevaporated in vacuo
  9. customThe residue was crystallized from methylene chloride/petroleum ether

Sources & evidence

ORD record
ord-7f927d0ae02b41bda61235ccffde1139
Source dataset
uspto-grants-1991_01
Patent number
US04981861

Reaction notes

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