Nitric Acid → 2-Methyl-5-nitroimidazole

HRID 1707104Notes

Reaction equation

HRID 1707104 reaction equation
[CH3:1][C:2]1[NH:3][CH:4]=[CH:5][N:6]=1.S(=O)(=O)(O)O.S([O-])([O-])(=O)=O.[N+:17]([O-])([OH:19])=[O:18]>>[CH3:1][C:2]1[NH:3][C:4]([N+:17]([O-:19])=[O:18])=[CH:5][N:6]=1

Participants

5

Reactant 4

HCID 944Nitric Acid2×HCID 1117Sulfate IonHCID 1118Sulfuric Acid4×HCID 127492-Methylimidazole3×

Product 1

HCID 127602-Methyl-5-nitroimidazoleYield 60%

Procedure

Into a glass bottle of 750 ml, provided with a reflux condenser, 50 g of 2-methylimidazole was placed and while constantly stirring and cooling, 10 ml of sulphuric acid of 1.84 density were carefully and gradually introduced in such a way, that the temperature did not exceed 120° (2-methylimidazole is a free base and its transformation into the sulphate of 2-methylimidazole is a highly exothermic reaction). Then there was slowly introduced 20 ml of sulphuric acid and after lowering the temperature to about 50°, 100 ml of nitric acid with a density of 1.50 was poured in, and, if a too violent course of the reaction in the first stage was detected, the reaction could be inhibited by addition of several ml of nitric acid of 1.50 density. Then, after several minutes, as the intensity of the reaction and of the exothermic effect began to diminish sulphuric acid was added up to exhaustion of the entire quantity of 50 ml. After the sulphuric acid was added, the reflux condenser was removed and the temperature raised to 130°-150°. The solution remained for complete cooling and in a known manner, by means of neutralization with ammonia water, 4.5 g of 2-methyl-5-nitroimidazole were isolated corresponding to a yield of about 60% of theoretical.

Workup

  1. customInto a glass bottle of 750 ml, provided with a reflux condenser
  2. temperaturecooling
  3. additiongradually introduced in such a way
  4. customdid not exceed 120°
  5. customa highly exothermic reaction)
  6. customto about 50°
  7. customif a too violent course of the reaction in the first stage
  8. customthe reaction
  9. waitThen, after several minutes
  10. customas the intensity of the reaction
  11. additionwas added up to exhaustion of the entire quantity of 50 ml
  12. customthe reflux condenser was removed
  13. temperaturethe temperature raised to 130°-150°
  14. temperaturefor complete cooling and in a known manner, by means of neutralization with ammonia water

Sources & evidence

ORD record
ord-5433c7f0443546648d7046cbfc5f14a0
Source dataset
uspto-grants-1980_06
Patent number
US04209631

Reaction notes

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