Benzene → Gramine

HRID 2212809Notes

Reaction equation

HRID 2212809 reaction equation
[CH:1](=[N:8][CH:9](C)C)C1C=CC=CC=1.[NH:12]1[C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH:14]=[CH:13]1.[CH:21]1C=CC=CC=1>>[CH3:1][N:8]([CH2:9][C:14]1[C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][C:20]=2[NH:12][CH:13]=1)[CH3:21]

Participants

4

Reactant 3

HCID 241BenzeneHCID 798IndoleHCID 959622-Propanamine, N-(phenylmethylene)-

Product 1

HCID 6890Gramine

Conditions

Temperature
0 °C

Procedure

To a solution of N-benzylideneisopropylamine (7.5 g, 51 mmol) in benzene (10 mL) at 0° C. under a nitrogen blanket was added a solution of indole (5.0 g, 43 mmol) AcOH (30 mL) over a 3-hour period, after which the stirring was continued at 0° C. for an additional 3 hours. The bulk of the solvent was removed under reduced pressure and the remaining reaction mixture was poured into 400 mL of ice water. The mixture was extracted with Et2O (3×75 mL), and the aqueous layer was cooled to 0° C. and made basic with 30% aqueous NaOH to a pH 11–12 range. The precipitate was extracted with CH2Cl2 (2×75 mL) and the combined organic extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure to provide gramine Intermediate 6 as a yellow semisolid (3.06 g, 27%): TLC Rf (1:1 CH2Cl2/EtOAC)=0.45.

Workup

  1. customThe bulk of the solvent was removed under reduced pressure
  2. customthe remaining reaction mixture
  3. extractionThe mixture was extracted with Et2O (3×75 mL)
  4. extractionThe precipitate was extracted with CH2Cl2 (2×75 mL)
  5. dry with materialthe combined organic extracts were dried over Na2SO4
  6. filtrationfiltered
  7. customthe solvent was removed under reduced pressure

Sources & evidence

ORD record
ord-425153fc0dd34c08be77bd0a53469a24
Source dataset
uspto-grants-2006_09
Patent number
US07105506B2

Reaction notes

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