Nitric Acid → 1H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-4-nitro-, ethyl ester

HRID 1874998Notes

Reaction equation

HRID 1874998 reaction equation
[N+:1]([O-:4])(O)=[O:2].[CH3:5][C:6]1[CH:10]=[C:9]([CH3:11])[NH:8][C:7]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13].C(=O)(O)[O-].[Na+]>>[CH3:5][C:6]1[C:10]([N+:1]([O-:4])=[O:2])=[C:9]([CH3:11])[NH:8][C:7]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13]

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1374771H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-, ethyl esterHCID 516892Sodium Bicarbonate

Product 1

HCID 1385181H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-4-nitro-, ethyl esterYield 14%

Conditions

Temperature
0 °C

Procedure

Nitric acid (70 w/w %, 5 mL) was added to ethyl 3,5-dimethyl-1H-pyrrole-2-carboxylate (1.0 g, 6.0 mmol) cooled to 0° C. The reaction mixture was stirred and allowed to warm to RT over 1 h. The reaction mixture was poured into an ice bath with sat. sodium bicarbonate (25 mL) and extracted with EtOAc (3×50 mL), the organic layers combined, dried over sodium sulfate, filtered and evaporated. Purification by column chromatography afforded ethyl 3,5-dimethyl-4-nitro-1H-pyrrole-2-carboxylate (0.185 g, 14%) as a white solid. 1H NMR (400 MHz, DMSO-d5): δ ppm 12.49 (br. s., 1H) 4.26 (q, 2H) 2.51 (s, 3H) 2.50 (s, 3H) 1.28 (t, 3H). MS: m/z 213.3 (M+1).

Workup

  1. temperatureto warm to RT over 1 h
  2. extractionextracted with EtOAc (3×50 mL)
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customPurification by column chromatography

Sources & evidence

ORD record
ord-51a200dad160441fa357153d78432766
Source dataset
uspto-grants-2012_11
Patent number
US08304419B2

Reaction notes

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