Diisobutylaluminum hydride → 3-Bromo-5-(3-ethoxypropyl)-4-methylbenzaldehyde

HRID 337652Notes

Reaction equation

HRID 337652 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:10]=[C:11]([CH2:14][CH2:15][CH2:16][O:17][CH2:18][CH3:19])[C:12]=1[CH3:13])[C:5](OCC)=[O:6].CC(C[AlH]CC(C)C)C.CC(OI1(OC(C)=O)(OC(C)=O)OC(=O)C2C=CC=CC1=2)=O.C(=O)(O)[O-].[Na+]>ClCCl.CCOCC>[Br:1][C:2]1[CH:3]=[C:4]([CH:10]=[C:11]([CH2:14][CH2:15][CH2:16][O:17][CH2:18][CH3:19])[C:12]=1[CH3:13])[CH:5]=[O:6]

Participants

7

Reactant 4

HCID 14487Diisobutylaluminum hydrideHCID 159087TriacetoxyperiodinaneHCID 516892Sodium BicarbonateHCID 66896071Ethyl 3-bromo-5-(3-ethoxypropyl)-4-methylbenzoate

Product 1

HCID 871956313-Bromo-5-(3-ethoxypropyl)-4-methylbenzaldehyde

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a dichloromethane (0.07 M) solution of ethyl 3-bromo-5-(3-ethoxypropyl)-4-methylbenzoate (1 eq.) from the previous step was added DIBAL-H (1.5 M solution in toluene, 2.2 eq.). The resulting solution was stirred at RT for 1.5 h and then carefully quenched with 10% aq. HCl. The aqueous layer was separated and back-extracted with ether. The combined organic extracts were washed further with brine, dried over Na2SO4, filtered and the filtrate concentrated in vacuo. The crude alcohol thus obtained was taken up again in dichloromethane (0.07 M) and then added Dess-Martin periodinane (1.0 eq.) and sodium bicarbonate (1.2 eq.). After stirring at RT for 40 min, the reaction mixture was diluted with ether and washed sequentially with sat. aq. NaHSO3, 1 N aq. NaOH, water and brine. The organic extract was dried over Na2SO4, filtered and the filtrate concentrated in vacuo. Purification of the crude product by way of flash chromatography (SiO2, Hex→1:1 (v/v) Hex:EtOAc) afforded the title compound as a colorless oil.

Workup

  1. customcarefully quenched with 10% aq. HCl
  2. customThe aqueous layer was separated
  3. extractionback-extracted with ether
  4. washThe combined organic extracts were washed further with brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationthe filtrate concentrated in vacuo
  8. customThe crude alcohol thus obtained
  9. stirringAfter stirring at RT for 40 min
  10. washwashed sequentially with sat. aq. NaHSO3, 1 N aq. NaOH, water and brine
  11. extractionThe organic extract
  12. dry with materialwas dried over Na2SO4
  13. filtrationfiltered
  14. concentrationthe filtrate concentrated in vacuo
  15. customPurification of the crude product by way of flash chromatography (SiO2, Hex→1:1 (v/v) Hex:EtOAc)

Sources & evidence

ORD record
ord-f5ff9729c8e343378b6cb0dcc232ee63
Source dataset
uspto-grants-2014_11
Patent number
US08889714B2

Reaction notes

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