Sulfuric Acid → Methyl 6-nitro-1H-indole-2-carboxylate

HRID 1874831Notes

Reaction equation

HRID 1874831 reaction equation
S(=O)(=O)(O)O.[N+:6]([C:9]1[CH:17]=[C:16]2[C:12]([CH:13]=[C:14]([C:18]([OH:20])=[O:19])[NH:15]2)=[CH:11][CH:10]=1)([O-:8])=[O:7].[C:21](=O)(O)[O-].[Na+]>CO>[N+:6]([C:9]1[CH:17]=[C:16]2[C:12]([CH:13]=[C:14]([C:18]([O:20][CH3:21])=[O:19])[NH:15]2)=[CH:11][CH:10]=1)([O-:8])=[O:7]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 47149976-nitro-1H-indole-2-carboxylic Acid

Product 1

HCID 11816863Methyl 6-nitro-1H-indole-2-carboxylateYield 81%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Sulfuric acid (1 mL, 18.76 mmol) was added to a suspension of 6-nitro-1H-indole-2-carboxylic acid (0.5 g, 2.425 mmol) in methanol (5 mL). The mixture was heated to reflux for 2 h. The reaction mixture was cooled to RT, poured into ice/water, neutralized with sodium bicarbonate, and extracted with ethyl acetate. The organic extracts were combined, dried over sodium sulfate, and concentrated to give the title compound (0.433 g, 81%) as a yellow solid. 1H NMR (400 MHz, CDCl3): δ ppm 9.31 (s, 1H), 8.41 (s, 1H), 8.05 (dd, 1H), 7.79 (d, 1H), 7.29 (s, 1H), 3.70-4.24 (m, 3H). MS: m/z 221 (M+1).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2 h
  3. extractionextracted with ethyl acetate
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-aa846aa3840a41c08d1cb458fb33e611
Source dataset
uspto-grants-2012_11
Patent number
US08304419B2

Reaction notes

Loading…