Hydrochloric Acid → Ipronidazole-hydroxy

HRID 441710Notes

Reaction equation

HRID 441710 reaction equation
[CH3:1][N:2]1[C:6]([N+:7]([O-:9])=[O:8])=[CH:5][N:4]=[C:3]1[CH:10]([CH3:12])[CH3:11].[O:13]=O.Cl>C1(C)C=CC=CC=1.C(OP(OCC)OCC)C.CN(C)C=O>[OH:13][C:10]([C:3]1[N:2]([CH3:1])[C:6]([N+:7]([O-:9])=[O:8])=[CH:5][N:4]=1)([CH3:12])[CH3:11]

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 977OxygenHCID 26951Ipronidazole

Product 1

HCID 598402Ipronidazole-hydroxyYield 23.8%

Reagents, catalysts & solvents 3

HCID 1140TolueneSolventHCID 6228DimethylformamideSolventHCID 31215Triethyl phosphiteSolvent

Procedure

A total of 45 ml of a 2.25-N solution of sodium tert.amylate in toluene and 11.2 ml of triethylphosphite were added to a solution, cooled to -15°, of 8.5 g of 1-methyl-2-isopropyl-5-nitroimidazole in 85 ml of dimethylformamide. A strong oxygen stream was conducted through this mixture for 6 hours at a temperature of -10° to -15° while stirring vigorously. The mixture was then neutralized by the addition of 45 ml of 2-N hydrochloric acid and concentrated on a rotary evaporator at 50°/12 Torr. The residue was taken up in 250 ml of water and the aqueous solution extracted 3 times with 250 ml portions of dichloromethane. The combined dichloromethane extracts were washed with a small amount of water and concentrated to dryness. The residue was then taken up in ethyl acetate and chromatographed on 600 g of silica gel with ethyl acetate. After evaporation of the solvent on a rotary evaporator and crystallization from isopropyl ether, there were obtained 2.2 g of 2-(2-hydroxy-2-propyl)-1-methyl-5-nitroimidazole, melting point 106°-108°. The yield was 23.8%.

Workup

  1. concentrationconcentrated on a rotary evaporator at 50°/12 Torr
  2. extractionthe aqueous solution extracted 3 times with 250 ml portions of dichloromethane
  3. washThe combined dichloromethane extracts were washed with a small amount of water
  4. concentrationconcentrated to dryness
  5. customchromatographed on 600 g of silica gel with ethyl acetate
  6. customAfter evaporation of the solvent
  7. customon a rotary evaporator and crystallization from isopropyl ether

Sources & evidence

ORD record
ord-d7de7e06116f4f6fab0f25a9bbfe9cfe
Source dataset
uspto-grants-1977_08
Patent number
US04042597

Reaction notes

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