Formaldehyde → 1-Ethyl-4-hydroxy-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid Methyl Ester

HRID 1788894Notes

Reaction equation

HRID 1788894 reaction equation
[CH3:1][O:2][C:3](=[O:21])[CH2:4][C:5]1([CH2:19][CH3:20])[C:10]2[NH:11][C:12]3[C:17]([C:9]=2[CH:8](N)[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3.[OH2:22].C=O>C1COCC1>[CH3:1][O:2][C:3](=[O:21])[CH2:4][C:5]1([CH2:19][CH3:20])[C:10]2[NH:11][C:12]3[C:17]([C:9]=2[CH:8]([OH:22])[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3

Participants

5

Reactant 3

HCID 712FormaldehydeHCID 962WaterHCID 543235014-Amino-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid methyl ester

Product 1

HCID 140647231-Ethyl-4-hydroxy-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid Methyl EsterYield 66.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-amino-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid methyl ester (6 g, 0.020 mol) in 50 mL THF was added 50 mL of H2O and paraformaldehyde (5 g) and the solution was heated at reflux for 2 hours under nitrogen. It was then cooled, concentrated in vacuo, and diluted with ethyl acetate. The ethyl acetate layer was washed with saturated sodium bicarbonate solution, brine, dried and concentrated in vacuo. The residue was purified by flash chromatography eluting with hexane to give a white solid (4 g, 66.4% ) m.p. 86°-90° C.

Workup

  1. temperaturethe solution was heated
  2. temperatureat reflux for 2 hours under nitrogen
  3. temperatureIt was then cooled
  4. concentrationconcentrated in vacuo
  5. additiondiluted with ethyl acetate
  6. washThe ethyl acetate layer was washed with saturated sodium bicarbonate solution, brine
  7. customdried
  8. concentrationconcentrated in vacuo
  9. customThe residue was purified by flash chromatography
  10. washeluting with hexane

Sources & evidence

ORD record
ord-a52449461f8f4b61888e8d7e221d8387
Source dataset
uspto-grants-1987_08
Patent number
US04686213

Reaction notes

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