Carbon Dioxide → 3-Ethoxy-1-isopropyl-4-nitro-1,5-dihydro-pyrrol-2-one

HRID 649301Notes

Reaction equation

HRID 649301 reaction equation
[CH2:1]([O:3][C:4]1[C:5](=[O:15])[N:6]([CH:12]([CH3:14])[CH3:13])[CH2:7][C:8]=1C(O)=O)[CH3:2].[N+:16]([O-])([OH:18])=[O:17].C(=O)=O>S(=O)(=O)(O)O>[CH:12]([N:6]1[CH2:7][C:8]([N+:16]([O-:18])=[O:17])=[C:4]([O:3][CH2:1][CH3:2])[C:5]1=[O:15])([CH3:14])[CH3:13]

Participants

5

Reactant 3

HCID 280Carbon DioxideHCID 944Nitric AcidHCID 141275444-Ethoxy-1-isopropyl-5-oxo-2,5-dihydro-1H-pyrrole-3-carboxylic acid3×

Product 1

HCID 141275453-Ethoxy-1-isopropyl-4-nitro-1,5-dihydro-pyrrol-2-one

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
-5 °C

Procedure

3-Ethoxy-1-isopropyl-2-oxo-3-pyrroline-4-carboxylic acid (5b, 8 g, 0.0376 mol) in powdered form was added in small portions through a seive to a stirred mixture of 70 mL of concentrated sulfuric acid and 4.7 mL of white fuming nitric acid (90%) that had been cooled to -5° C. prior to the start of the addition of 5b. The rate of addition of 5b was controlled so as to keep the temperature of the reaction mixture from rising above -3° C. and to minimize accumulation of undissolved lumps of starting material in the mixture. Stirring was continued for 3 h at -3° C. Effervescence caused by carbon dioxide evolution began after the mixture had been stirred for a few minutes and virtually ceased after an hour of two. When the mixture was poured slowly into a stirred suspension of 1 L of crushed ice, the product separated as a white crystalline precipitate. It was collected by filtration as soon as the ice was melted and washed on the filter with a small amount of cold water. The yield was 4.9 g (61%), mp 47°-47° C. Recrystallization from acetone or benzene and petroleum ether (bp 30°-60° C.) raised the melting point to 49°-50° C.: 1H NMR (CDCl3) δ4.90 (q, 2H, OCH2CH3, J=7 Hz), 4.40 (septet, 1H, NCH(CH3)2, J=7 Hz), 4.15 (s, 2H, CH 2 of pyrroline), 1.55-1.20 (t+d, 9H, overlap of --OCH2CHc and NCH(CH3)2, J=7 Hz); IR (thin film) 3.34, 3.39, 3.47, 5.87, 6.08, 6.69, 6.92, 7.17, 7.3, 7.30, 7.38, 7.67, 7.93, 8.10, 8.40, 8.55, 8.75, 8.87, 9.05 μm; UV (95% EtOH) 293 nm (ε9800).

Workup

  1. customfrom rising above -3° C.
  2. stirringhad been stirred for a few minutes
  3. waitvirtually ceased after an hour of two
  4. customthe product separated as a white crystalline precipitate
  5. filtrationIt was collected by filtration as soon as the ice
  6. washwashed on the
  7. filtrationfilter with a small amount of cold water
  8. customRecrystallization from acetone or benzene and petroleum ether (bp 30°-60° C.)
  9. temperatureraised the melting point to 49°-50° C.

Sources & evidence

ORD record
ord-ccb776a6cf264a788370c77500533935
Source dataset
uspto-grants-1988_04
Patent number
US04739076

Reaction notes

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