Trifluoroacetic acid → Beta-Carboline

HRID 2212811Notes

Reaction equation

HRID 2212811 reaction equation
F[C:2](F)(F)[C:3](O)=O.C[CH:9]([C:15]1[C:23]2[C:18](=[CH:19][CH:20]=[CH:21][CH:22]=2)[NH:17]C=1)[C@@H:10](C(O)=O)[NH2:11].C1C(C=O)=CC2OCOC=2C=1.C([O-])(O)=O.[Na+]>C(Cl)Cl>[CH:2]1[C:3]2[NH:17][C:18]3[C:23](=[CH:22][CH:21]=[CH:20][CH:19]=3)[C:15]=2[CH:9]=[CH:10][N:11]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 8438PiperonalHCID 516892Sodium BicarbonateHCID 53748860HCID 53748860, compound

Product 1

HCID 64961Beta-Carboline

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

Trifluoroacetic acid (0.62 mL, 8.11 mmol) was added to a mixture of Intermediate 13a (950 mg, 3.86 mmol) and piperonal (695 mg, 4.63 mmol) in CH2Cl2. (25 mL) at 0° C. under a nitrogen blanket, after which the mixture was warmed to room temperature stirred for 24 hours. The reaction mixture was diluted with CH2Cl2 (50 mL) and neutralized with saturated NaHCO3 solution (10 mL). The organic layer was washed with water (10 mL) and brine (15 mL), dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. The residue was purified by flash column chromatography, eluting with CH2Cl2/EtOAc (10:1), to afford β-carboline Intermediate 18 as an inseparable mixture of cis and trans isomers, and was used for the next step without further purification (950 mg, 65%): TLC Rf (10:1 CH2Cl2/EtOAc)=0.40.

Workup

  1. washThe organic layer was washed with water (10 mL) and brine (15 mL)
  2. dry with materialdried over Na2SO4
  3. filtrationfiltered
  4. customthe solvent was removed under reduced pressure
  5. customThe residue was purified by flash column chromatography
  6. washeluting with CH2Cl2/EtOAc (10:1)

Sources & evidence

ORD record
ord-0d822d970fe54b1a815d712f0524e36b
Source dataset
uspto-grants-2006_09
Patent number
US07105506B2

Reaction notes

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