Trifluoroacetic acid → Ethyl Indoline-2-carboxylate

HRID 2227430Notes

Reaction equation

HRID 2227430 reaction equation
FC(F)(F)C(O)=O.[BH3-]C#N.[Na+].[CH2:12]([O:14][C:15]([C:17]1[NH:18][C:19]2[C:24]([CH:25]=1)=[CH:23][CH:22]=[CH:21][CH:20]=2)=[O:16])[CH3:13]>O>[CH2:12]([O:14][C:15]([CH:17]1[CH2:25][C:24]2[C:19](=[CH:20][CH:21]=[CH:22][CH:23]=2)[NH:18]1)=[O:16])[CH3:13]

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 73125Ethyl indole-2-carboxylateHCID 5003444Sodium cyanoborohydride

Product 1

HCID 11949691Ethyl Indoline-2-carboxylateYield 90%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To cooled trifluoroacetic acid (40 mL) at 0° C., NaCNBH3 (1.57 g, 25 mmol) was added portionwise with stirring. The reaction mixture was stirred for 15 min, and to which indole-2-carboxylic acid ethyl ester (1.2 g, 6.35 mmol) was added slowly, then the mixture was stirred at rt for an hour. After the completion of the reaction, water (150 mL) was added to the mixture, and which was stirred for 5 hr. The reaction was extracted by CH2Cl2 (40 mL×3), then organic layer was washed with saturated aqueous solution of NaHCO3 (40 mL×2) and water (40 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=9:1) to give the desired compound (1.09 g, 90%).

Workup

  1. stirringThe reaction mixture was stirred for 15 min
  2. stirringthe mixture was stirred at rt for an hour
  3. additionwas added to the mixture, and which
  4. stirringwas stirred for 5 hr
  5. extractionThe reaction was extracted by CH2Cl2 (40 mL×3)
  6. washorganic layer was washed with saturated aqueous solution of NaHCO3 (40 mL×2) and water (40 mL)
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=9:1)

Sources & evidence

ORD record
ord-f2964c57486a4d95abe1a533ccad3707
Source dataset
uspto-grants-2002_07
Patent number
US06413983B1

Reaction notes

Loading…