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

HRID 2289215Notes

Reaction equation

HRID 2289215 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>[N+:12]([C:5]1[N:4]=[C:3]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:2]([CH3:1])[CH:6]=1)([O-:14])=[O:13]

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

Compound (17) was carefully dissolved in 1000 ml of concentrated sulfuric acid cooled to 0° C. 90% nitric acid (1 liter) 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 minutes. The reaction was cooled with an ice bath, and quenched by pouring onto 10 liters of ice. The resulting blue solution was then extracted with 20 liters of dichloromethane and the combined extracts were dried and concentrated in vacuo to yield a tan solid which was recrystallized from 22 liters of 21:1 carbon tetrachloride/ethanol. The resulting white crystals were collected by vacuum filtration to provide pure (10). (103 g, 22% yield). TLC (7:2 benzene/ethyl acetate) Rf 0.5, 1H NMR (DMSO-d6) δ 8.61 (s, 1 H), 4.33 (1, 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, 1508, 1498, 1381, 1310, 1260, 1147, 1122, 995, 860, 827, 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 minutes
  3. temperatureThe reaction was cooled with an ice bath
  4. customquenched
  5. additionby pouring onto 10 liters of ice
  6. extractionThe resulting blue solution was then extracted with 20 liters of dichloromethane
  7. customthe combined extracts were dried
  8. concentrationconcentrated in vacuo
  9. customto yield a tan solid which
  10. customwas recrystallized from 22 liters of 21:1 carbon tetrachloride/ethanol
  11. filtrationThe resulting white crystals were collected by vacuum filtration

Sources & evidence

ORD record
ord-cbd77014708947288574156ce903319d
Source dataset
uspto-grants-2000_07
Patent number
US06090947

Reaction notes

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