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

HRID 1476977Notes

Reaction equation

HRID 1476977 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

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-2f0c923ceedc4853a9f725fd4570919c
Source dataset
uspto-grants-2016_08
Patent number
US09402836B2

Reaction notes

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