Methanol → methyl 7-methyl-1H-indole-4-carboxylate

HRID 62342Notes

Reaction equation

HRID 62342 reaction equation
[CH3:1][C:2]1[C:10]2[NH:9][CH:8]=[CH:7][C:6]=2[C:5]([C:11]([OH:13])=[O:12])=[CH:4][CH:3]=1.S(=O)(=O)(O)O.[CH3:19]O>>[CH3:1][C:2]1[C:10]2[NH:9][CH:8]=[CH:7][C:6]=2[C:5]([C:11]([O:13][CH3:19])=[O:12])=[CH:4][CH:3]=1

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 53399316HCID 53399316, compound

Product 1

HCID 67465603methyl 7-methyl-1H-indole-4-carboxylate

Procedure

Under N2 atmosphere, 7-methyl-1H-indole-4-carboxylic acid (1 g, 5.71 mmol), sulfuric acid (300 μL, 5.63 mmol) and methanol (50 mL) were heated at reflux for 10 h. The MeOH was removed in vacuo and the residue dissolved in 30 mL DCM. The solution was washed with water and saturated NaHCO3, dried over MgSO4, filtered and concentrated. The residue was purified by column chromatography (Biotage; 0% to 100% EtOAc:Hex; 25 g-HP-silica gel column) to give the title compound. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.59 (s, 3H), 4.00 (s, 3H), 7.08 (d, J=7.58 Hz, 1H), 7.20-7.26 (m, 1H), 7.38 (t, J=2.78 Hz, 1H), 7.88 (d, J=7.58 Hz, 1H), 8.32 (br. s., 1H).

Workup

  1. temperatureat reflux for 10 h
  2. customThe MeOH was removed in vacuo
  3. dissolutionthe residue dissolved in 30 mL DCM
  4. washThe solution was washed with water and saturated NaHCO3
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by column chromatography (Biotage; 0% to 100% EtOAc:Hex; 25 g-HP-silica gel column)

Sources & evidence

ORD record
ord-9d2e246a2b4a4ae588362901e51a8fa4
Source dataset
uspto-grants-2016_09
Patent number
US09446041B2

Reaction notes

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