Boron trifluoride etherate → HCID 13477702, compound

HRID 1894741Notes

Reaction equation

HRID 1894741 reaction equation
[C:1]([O:6][CH2:7][CH3:8])(=[O:5])[C:2]([CH3:4])=O.[N:9]1(N)[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[CH2:11][CH2:10]1.B(F)(F)F.CCOCC.C(OCC)(=O)C>C(O)C>[CH2:7]([O:6][C:1]([C:2]1[N:9]2[CH2:10][CH2:11][C:12]3[CH:13]=[CH:14][CH:15]=[C:16]([CH:4]=1)[C:17]2=3)=[O:5])[CH3:8]

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 8857Ethyl AcetateHCID 12041Ethyl pyruvateHCID 27609322,3-dihydro-1H-indol-1-amine

Product 1

HCID 13477702HCID 13477702, compoundYield 16.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl pyruvate (3.7 ml, 33.3 mmol) was added to a solution of 2,3-dihydro-indol-1-ylamine (4.216 g, 31.4 mmol) in absolute ethanol (40 ml). The mixture was heated to reflux for 1 hour before being evaporated to dryness. The residue was dissolved in acetic acid (40 ml) and boron trifluoride etherate (4.0 ml 31.4 mmol) added. The mixture was heated to reflux for 1 hour then poured into ethyl acetate (200 ml). The ethyl acetate was washed with water (1 L), saturated sodium hydrogen carbonate (2×300 ml) and brine (100 ml). After drying over anhydrous magnesium sulfate the mixture was evaporated to dryness and the residue purified by flash column chromatography (SiO2, 7% to 10% EtOAc in hexanes) to afford 4,5-dihydro-pyrrolo[3,2,1-hi]indole-2-carboxylic acid ethyl ester as a yellow solid (1.117 g). 400 MHz 1H NMR (DMSO-d6) δ: 7.35 (d, J=6.8 Hz, 1H), 7.12 (s, 1H), 7.04-6.99 (m, 2H), 4.73 (t, J=6.8 Hz, 2H), 4.37 (q, J=7.2 Hz, 2H), 3.77 (t, J=6.8 Hz, 2H), 1.41 (t, 6.8 Hz, 3H); LCMS: 216 [M+H].

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 1 hour
  3. custombefore being evaporated to dryness
  4. dissolutionThe residue was dissolved in acetic acid (40 ml)
  5. temperatureThe mixture was heated
  6. temperatureto reflux for 1 hour
  7. washThe ethyl acetate was washed with water (1 L), saturated sodium hydrogen carbonate (2×300 ml) and brine (100 ml)
  8. dry with materialAfter drying over anhydrous magnesium sulfate the mixture
  9. customwas evaporated to dryness
  10. customthe residue purified by flash column chromatography (SiO2, 7% to 10% EtOAc in hexanes)

Sources & evidence

ORD record
ord-fd50f6cf601d41f7995e18b0d772b51e
Source dataset
uspto-grants-2013_08
Patent number
US08513292B2

Reaction notes

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