Diisobutylaluminum hydride → Isoquinoline-3-carboxaldehyde

HRID 2111905Notes

Reaction equation

HRID 2111905 reaction equation
C[O:2][C:3]([C:5]1[N:6]=[CH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][CH:11]=[CH:10][CH:9]=2)=O.CC(C[AlH]CC(C)C)C>O1CCCC1>[CH:7]1[C:8]2[C:13](=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:14]=[C:5]([CH:3]=[O:2])[N:6]=1

Participants

4

Reactant 2

HCID 14487Diisobutylaluminum hydrideHCID 725374Methyl 3-isoquinolinecarboxylate

Product 1

HCID 231555Isoquinoline-3-carboxaldehydeYield 54.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled solution 0° C. of isoquinoline-3-carboxylic acid methyl ester (1.0 g, 5.34 mmol) in anhydrous tetrahydrofuran (100 ml), is added a solution of DIBAL-H (11.8 ml, 11.8 mmol). The reaction mixture is stirred at 0° C. for 2 hours and then quenched with saturated aqueous sodium potassium tartrate and stirred for 2 hours. The layers are separated and the aqueous layer is extracted with ethyl acetate. The combined organic extracts are washed with 1N HCl, 2N NaOH, and dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The crude reaction mixture is purified on silica gel eluting with 20% ethyl acetate/hexanes to give isoquinoline-3-carboxaldehyde (0.46 g, 54%). 1H NMR (CDCl3): δ=10.24 (1H, brs), 9.32 (1H, brs), 8.35 (1H, brs), 8.02 (2H, brd), 7.77 (2H, brs).

Workup

  1. customquenched with saturated aqueous sodium potassium tartrate
  2. stirringstirred for 2 hours
  3. customThe layers are separated
  4. extractionthe aqueous layer is extracted with ethyl acetate
  5. washThe combined organic extracts are washed with 1N HCl, 2N NaOH
  6. dry with materialdried over anhydrous Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customThe crude reaction mixture
  10. customis purified on silica gel eluting with 20% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-e2bed9e26f01485eb136f1befaa7d531
Source dataset
uspto-grants-2009_04
Patent number
US07521462B2

Reaction notes

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