Methyl indole-6-carboxylate → Methyl indoline-6-carboxylate

HRID 2235123Notes

Reaction equation

HRID 2235123 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:13]=[C:12]2[C:8]([CH:9]=[CH:10][NH:11]2)=[CH:7][CH:6]=1)=[O:4].C([BH3-])#N.[Na+]>C(O)(=O)C>[CH3:1][O:2][C:3]([C:5]1[CH:13]=[C:12]2[C:8]([CH2:9][CH2:10][NH:11]2)=[CH:7][CH:6]=1)=[O:4]

Participants

4

Reactant 2

HCID 639844Methyl indole-6-carboxylateHCID 5003444Sodium cyanoborohydride2×

Product 1

HCID 16244446Methyl indoline-6-carboxylate

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
15 °C

Procedure

A solution of indole-6-carboxylic acid methyl ester (534 mg, 3.05 mmol) in acetic acid (7.5 ml) was cooled to 0° C. Sodium cyanoborohydride (580 mg, 9.2 mmol, 3 equiv.) was added and the mixture stirred at 15° C. for 40 min. A further aliquot of sodium cyanoborohydride (193 mg, 3.05 mmol, 1 equiv.) was added, and the reaction mixture was stirred for 30 min. at room temperature. The solvent was then evaporated, and the residue dissolved in dichloromethane and washed with 1N NaOH. The organic phase was dried with Na2SO4 and evaporated, yielding 2,3-dihydro-1H-indole-6-carboxylic acid methyl ester as a light yellow solid, 494 mg (77%). This was used as such in the following reaction.

Workup

  1. stirringthe reaction mixture was stirred for 30 min. at room temperature
  2. customThe solvent was then evaporated
  3. dissolutionthe residue dissolved in dichloromethane
  4. washwashed with 1N NaOH
  5. dry with materialThe organic phase was dried with Na2SO4
  6. customevaporated

Sources & evidence

ORD record
ord-2fc76d86a8b344df8a726e88d8a34991
Source dataset
uspto-grants-2010_05
Patent number
US07713996B2

Reaction notes

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