Trifluoroacetic acid → Methyl (1R,3R)-1-(1,3-benzodioxol-5-yl)-2,3,4,9-tetrahydro-1H-pyrido(3,4-b)indole-3-carboxylate

HRID 396146Notes

Reaction equation

HRID 396146 reaction equation
[CH3:1][O:2][C:3](=[O:16])[C@@H:4]([CH2:6][C:7]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[NH:9][CH:8]=1)[NH2:5].[CH:17]1[C:22]([CH:23]=O)=[CH:21][C:20]2[O:25][CH2:26][O:27][C:19]=2[CH:18]=1.FC(F)(F)C(O)=O>C(Cl)Cl>[CH2:26]1[O:27][C:19]2[CH:18]=[CH:17][C:22]([C@@H:23]3[C:8]4[NH:9][C:10]5[C:15]([C:7]=4[CH2:6][C@H:4]([C:3]([O:2][CH3:1])=[O:16])[NH:5]3)=[CH:14][CH:13]=[CH:12][CH:11]=5)=[CH:21][C:20]=2[O:25]1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 8438PiperonalHCID 168016Methyl D-Tryptophanate

Product 1

HCID 10269318Methyl (1R,3R)-1-(1,3-benzodioxol-5-yl)-2,3,4,9-tetrahydro-1H-pyrido(3,4-b)indole-3-carboxylateYield 36.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of D-tryptophan methyl ester (11 g) and piperonal (7.9 g) in anhydrous CH2Cl2 (400 mL) cooled at 0° C. was added dropwise trifluoroacetic acid (7.7 mL) and the solution was allowed to react at ambient temperature. After 4 days, the yellow solution was diluted with CH2Cl2 (200 mL) and washed with a saturated aqueous solution of NaHCO3, then with water (3×200 mL) and dried over Na2SO4. The organic layer was evaporated under reduced pressure and the residue containing the two geometric isomers was purified by flash chromatography eluting with dichloromethane/ethyl acetate (97/3) to give as the first eluting product the title compound (6.5 g).

Workup

  1. customto react at ambient temperature
  2. washwashed with a saturated aqueous solution of NaHCO3
  3. dry with materialwith water (3×200 mL) and dried over Na2SO4
  4. customThe organic layer was evaporated under reduced pressure
  5. additionthe residue containing the two geometric isomers
  6. customwas purified by flash chromatography
  7. washeluting with dichloromethane/ethyl acetate (97/3)

Sources & evidence

ORD record
ord-538c62d37ba9478ab431af1e12fb68b8
Source dataset
uspto-grants-2003_08
Patent number
US06608065B1

Reaction notes

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