Aluminium lithium hydride → (9-ethyl-9H-carbazol-1-yl)methanol

HRID 659651Notes

Reaction equation

HRID 659651 reaction equation
[CH2:1]([N:3]1[C:15]2[C:14]([C:16](OC)=[O:17])=[CH:13][CH:12]=[CH:11][C:10]=2[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH3:2].[H-].[H-].[H-].[H-].[Li+].[Al+3]>C1COCC1>[CH2:1]([N:3]1[C:15]2[C:14]([CH2:16][OH:17])=[CH:13][CH:12]=[CH:11][C:10]=2[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH3:2]

Participants

4

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 67996321methyl 9-ethyl-9H-carbazole-1-carboxylate

Product 1

HCID 67996268(9-ethyl-9H-carbazol-1-yl)methanol

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A 50-mL round-bottom flask was placed a solution of methyl 9-ethyl-9H-carbazole-1-carboxylate (1.3 g, 5.14 mmol, 1.00 equiv) in THF (50 mL). To the mixture was added LiAlH4 (840 mg, 22.11 mmol, 4.00 equiv) in several batches at 0° C. and allowed to stir at this temperature 30 minutes. Then, the reaction was quenched with aqueous NaOH (2M, 12 mL). The mixture was then extracted with ethyl acetate (3×50 mL). Combined organic layers were dried over anhydrous sodium sulfate, filtered off and concentrated on a rotary evaporator. The residue was purified by a silica gel column chromatography eluted with dichloromethane/methanol (50:1) affording (9-ethyl-9H-carbazol-1-yl)methanol as white solid (1 g, (86%). Meanwhile, a 250-mL 3-necked round-bottom was charged with a solution of (COCl)2 (840 mg, 6.67 mmol, 1.50 equiv) in DCM (40 mL). To this was added DMSO (1 g, 12.80 mmol, 3.00 equiv)-78° C. and allowed to stir for 30 min at this temperature. To this solution was added a solution of (9-ethyl-9H-carbazol-1-yl)methanol (1 g, 4.44 mmol, 1.00 equiv) in DCM (5 mL) at −78° C. The resulting solution was stirred at −78° C. for 5 hours. Then, triethylamine (TEA) (10 mL) was added and allowed to stir an additional hour at −78° C. Upon completion, the reaction was quenched with water and extracted with DCM (3×50 mL). Combined organic layers were dried over anhydrous sodium sulfate, filtered off and concentrated on a rotary evaporator. The residue was purified by a silica gel column chromatography eluted with dichloromethane/methanol (50:1) affording 9-ethyl-9H-carbazole-1-carbaldehyde as light yellow solid (0.9 g, 90.8%).

Workup

  1. customA 50-mL round-bottom flask was placed
  2. customThen, the reaction was quenched with aqueous NaOH (2M, 12 mL)
  3. extractionThe mixture was then extracted with ethyl acetate (3×50 mL)
  4. dry with materialCombined organic layers were dried over anhydrous sodium sulfate
  5. filtrationfiltered off
  6. concentrationconcentrated on a rotary evaporator
  7. customThe residue was purified by a silica gel column chromatography
  8. washeluted with dichloromethane/methanol (50:1)

Sources & evidence

ORD record
ord-1b6d99b6ffde4ae0817df9f62493e0a3
Source dataset
uspto-grants-2011_12
Patent number
US08080566B1

Reaction notes

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