Dimethyl Sulfate → Ipronidazole

HRID 2397216Notes

Reaction equation

HRID 2397216 reaction equation
[CH:1]([C:4]1[NH:5][C:6]([N+:9]([O-:11])=[O:10])=[CH:7][N:8]=1)([CH3:3])[CH3:2].S(OC)(O[CH3:16])(=O)=O>C(O)=O>[CH3:16][N:5]1[C:6]([N+:9]([O-:11])=[O:10])=[CH:7][N:8]=[C:4]1[CH:1]([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 6497Dimethyl SulfateHCID 83389Imidazole, 2-isopropyl-4-nitro-

Product 1

HCID 26951IpronidazoleYield 72%

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Conditions

Temperature
5 °C

Procedure

155 parts of 2-isopropyl-5-nitroimidazole, 350 parts of formic acid and 126 parts of dimethyl sulfate are heated under reflux for 2 hours. The formic acid is distilled off in vacuo and the residue which remains is dissolved in 500 parts of water. A pH of 1.8 is set up with dilute aqueous ammonia solution and the solution is cooled for 2 hours at +5° C. The unreacted 2-isopropyl-5-nitroimidazole (15 parts) is suction filtered and the filtrate is adjusted to pH 10 by adding aqueous ammonia solution. After cooling for 2 hours at 5° C. the mixture is suction filtered and the end product is dried. 110 parts of 1-methyl-2-isopropyl-5-nitroimidazole having a melting point of 56° C. is obtained and this is equivalent to a yield of 72% of theory based on reacted 2-isopropyl-5-nitroimidazole.

Workup

  1. temperatureunder reflux for 2 hours
  2. distillationThe formic acid is distilled off in vacuo
  3. dissolutionthe residue which remains is dissolved in 500 parts of water
  4. temperaturethe solution is cooled for 2 hours at +5° C
  5. filtrationThe unreacted 2-isopropyl-5-nitroimidazole (15 parts) is suction filtered
  6. additionby adding aqueous ammonia solution
  7. filtrationfiltered
  8. customthe end product is dried

Sources & evidence

ORD record
ord-513a04a28fb24b05aba17858628c1cef
Source dataset
uspto-grants-1977_05
Patent number
US04021442

Reaction notes

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