1-Ethyl-4-hydroxy-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid Methyl Ester → HCID 13911142, compound

HRID 1788895Notes

Reaction equation

HRID 1788895 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](O)[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3.[CH2:22]([Mg]Br)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1>C(Cl)Cl.CCOCC.Cl[Ti](Cl)(Cl)Cl>[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]([CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3

Participants

6

Reactant 2

HCID 140647231-Ethyl-4-hydroxy-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid Methyl EsterHCID 178419663HCID 178419663, compound

Product 1

HCID 13911142HCID 13911142, compoundYield 51.5%

Reagents, catalysts & solvents 3

HCID 24193Titanium TetrachlorideCatalystHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of 1-ethyl-4-hydroxy-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid methyl ester (1 g, 3.6 mmol) in 60 mL of dry methylene chloride at -78° C. under nitrogen was added TiCl4 in one portion and then after ~10 minutes, a solution of benzyl magnesium bromide in ether was added in one portion and the reaction mixture was allowed to stir at -78° C. for ~30 minutes. The reaction was quenched with methanol (3 mL) at -78° C. and then poured into water (10 mL). The two layers were separated and the aqueous layer was then extracted with methylene chloride (2×100 mL), dried over magnesium sulfate and concentrated in vacuo. The crude product was passed through a pad of silica gel, eluting with 10% EtOAc in hexane to give 0.67 g (51.5%) of the product as an oil, which had isomer ratio of 75:25 by HPLC.

Workup

  1. waitafter ~10 minutes
  2. customThe reaction was quenched with methanol (3 mL) at -78° C.
  3. additionpoured into water (10 mL)
  4. customThe two layers were separated
  5. extractionthe aqueous layer was then extracted with methylene chloride (2×100 mL)
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated in vacuo
  8. washeluting with 10% EtOAc in hexane

Sources & evidence

ORD record
ord-3c249d2ea45e4d7eb9c39839b84aa498
Source dataset
uspto-grants-1987_08
Patent number
US04686213

Reaction notes

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