Nitric Acid → Ethyl 1-methyl-4-nitroimidazole-2-carboxylate

HRID 1634591Notes

Reaction equation

HRID 1634591 reaction equation
[CH3:1][N:2]1[CH:6]=[CH:5][N:4]=[C:3]1[C:7]([O:9][CH2:10][CH3:11])=[O:8].[N+:12]([O-])([OH:14])=[O:13]>S(=O)(=O)(O)O>[CH3:1][N:2]1[CH:6]=[C:5]([N+:12]([O-:14])=[O:13])[N:4]=[C:3]1[C:7]([O:9][CH2:10][CH3:11])=[O:8]

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 4261883ethyl 1-methyl-1H-imidazole-2-carboxylate

Product 1

HCID 2758876Ethyl 1-methyl-4-nitroimidazole-2-carboxylateYield 22%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

Ethyl 1-methylimidazole-2-carboxylate was carefully dissolved in 1000 mL of concentrated sulfuric acid cooled to 0° C. 90% nitric acid (1 L) was slowly added maintaining a temperature of 0° C. The reaction was then refluxed with an efficient condenser (−20° C.) in a well ventilated hood for 50 min. The reaction was cooled with an ice bath, and quenched by pouring onto 10 L ice. The resulting blue solution was then extracted with 20 L DCM, the combined extracts dried (sodium sulfate) and concentrated in vacuo to yield a tan solid which was recrystallized from 22 L of 21:1 carbon tetrachloride/ethanol. The resulting white crystals are collected by vacuum filtration to provide pure Ethyl 1-methyl-4-nitroimidazole-2-carboxylate. (103 g, 22% yield). TLC (7:2 benzene/ethyl acetate v/v) Rf 0.5, 1H NMR (DMSO-d6) δ 8.61 (s, 1H), 4.33 (q, 2 H, J=6.4 Hz), 3.97 (s, 3 H), 1.29 (t, 3 H, J=6.0 Hz), 13C NMR (DMSO-d6) δ 158.2, 145.4, 135.3, 127.4, 62.2, 37.3, 14.5; IR (KBr) 3139, 1719, 1541, 1498, 1381, 1310, 1260, 1122, 995, 860, 656.; FABMS m/e 200.066 (M+H 200.067 calc. for C7H10N3O4).

Workup

  1. temperaturemaintaining a temperature of 0° C
  2. temperatureThe reaction was then refluxed with an efficient condenser (−20° C.) in a well ventilated hood for 50 min
  3. temperatureThe reaction was cooled with an ice bath
  4. customquenched
  5. additionby pouring onto 10 L ice
  6. extractionThe resulting blue solution was then extracted with 20 L DCM
  7. dry with materialthe combined extracts dried (sodium sulfate)
  8. concentrationconcentrated in vacuo
  9. customto yield a tan solid which
  10. customwas recrystallized from 22 L of 21:1 carbon tetrachloride/ethanol
  11. filtrationThe resulting white crystals are collected by vacuum filtration

Sources & evidence

ORD record
ord-d25d033ead5e403ca60f2e3f7eb11684
Source dataset
uspto-grants-2003_01
Patent number
US06506906B1

Reaction notes

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