Diethyl Ether → 5-(1-Benzylindol-3-yl)-2,4-pentadienal

HRID 845509Notes

Reaction equation

HRID 845509 reaction equation
[CH2:1]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]([CH:17]=[CH:18][CH:19]=[CH:20][C:21](OCC)=[O:22])=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(OCC)C.[H-].[H-].[H-].[H-].[Li+].[Al+3]>O1CCCC1>[CH2:1]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]([CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=[O:22])=[CH:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 21226445Aluminium lithium hydrideHCID 54565894Ethyl 5-(1-benzylindol-3yl)-2,4-pentadienoate

Product 1

HCID 541315495-(1-Benzylindol-3-yl)-2,4-pentadienalYield 77.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 5-(1-benzylindol-3yl)-2,4-pentadienoate (1.5 g, 4.5 mmol) in 100 ml of diethyl of diethyl ether and 20 ml of tetrahydrofuran, stirred at 0° C. (ice bath), was added in portions 0.34 g (9 mmol) of LAH; the resulting mixture was stirred at room temperature for 26 hours, and worked up in manner similar to Example 13 to afford, after purifications by dry column chromatography (2:1, hexane:ethyl acetate), 1.2 g of the intermediate 2,4-pentadienol. This substance was dissolved in 250 ml of dichoromethane and 6 g of activated manganese dioxide was added. The suspension was stirred at room temperature for 6 hours. Manganese dioxide was removed by filtering through Celite® and washed thoroughly with a mixture of ethyl acetate and methylene chloride. The combined filtrate and washing were concentrated on a rotary evaporator to give 1 g of the product as an orange colored oil. This substance was used without purification in Example 15. NMR spectrum shows a singlet a 5.18 ppm and a doublet (J=7.5 Hz) at 9.48 ppm.

Workup

  1. customto afford
  2. dry with materialafter purifications by dry column chromatography (2:1, hexane:ethyl acetate), 1.2 g of the intermediate 2,4-pentadienol
  3. dissolutionThis substance was dissolved in 250 ml of dichoromethane
  4. addition6 g of activated manganese dioxide was added
  5. stirringThe suspension was stirred at room temperature for 6 hours
  6. customManganese dioxide was removed
  7. filtrationby filtering through Celite®
  8. washwashed thoroughly with a mixture of ethyl acetate and methylene chloride
  9. washThe combined filtrate and washing
  10. concentrationwere concentrated on a rotary evaporator

Sources & evidence

ORD record
ord-f28371b58cd14deab8cdacc5533a7013
Source dataset
uspto-grants-1988_07
Patent number
US04758586

Reaction notes

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