Acetic Acid → 2-(Cyclopropylamino)-1-methyl-1H-indole

HRID 1920991Notes

Reaction equation

HRID 1920991 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=[C:3]1C=O.[CH:13]1([NH2:16])[CH2:15][CH2:14]1.C(O)(=O)C.[BH3-]C#N.[Na+]>CO>[CH:13]1([NH:16][C:3]2[N:2]([CH3:1])[C:10]3[C:5]([CH:4]=2)=[CH:6][CH:7]=[CH:8][CH:9]=3)[CH2:15][CH2:14]1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 69828CyclopropylamineHCID 2671641-Methylindole-2-carboxaldehydeHCID 5003444Sodium cyanoborohydride

Product 1

HCID 225937332-(Cyclopropylamino)-1-methyl-1H-indoleYield 69.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 1-methylindole-2-carboxaldehyde (1.5 g, 10 mmole), cyclopropylamine (1.14 g, 20 mmole), and glacial acetic acid (0.6 mL, 10 mmole) in MeOH (30 mL) was added NaBH3CN (0.69 g, 11 mmole). The reaction was stirred at RT overnight, then was concentrated in vacuo. The residue was diluted with 10% NaOH and extracted with CH2Cl2. The combined organic extracts were washed with brine, dried over MgSO4, and concentrated. Flash chromatography on silica gel (3% MeOH/CH2Cl2) gave the title compound (1.3 g, 65%) as a semi-solid: MS (ES) m/e-201 (M+H)+.

Workup

  1. concentrationwas concentrated in vacuo
  2. additionThe residue was diluted with 10% NaOH
  3. extractionextracted with CH2Cl2
  4. washThe combined organic extracts were washed with brine
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-73120d9b91cb4e0eb0a20bc4b8ffe3b3
Source dataset
uspto-grants-2012_05
Patent number
US08173646B2

Reaction notes

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