Dimethyl Sulfoxide → 9-ethyl-9H-carbazole-1-carbaldehyde

HRID 659652Notes

Reaction equation

HRID 659652 reaction equation
C(Cl)(C(Cl)=O)=O.CS(C)=O.[CH2:11]([N:13]1[C:25]2[C:24]([CH2:26][OH:27])=[CH:23][CH:22]=[CH:21][C:20]=2[C:19]2[C:14]1=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH3:12].C(N(CC)CC)C>C(Cl)Cl>[CH2:11]([N:13]1[C:25]2[C:24]([CH:26]=[O:27])=[CH:23][CH:22]=[CH:21][C:20]=2[C:19]2[C:14]1=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH3:12]

Participants

6

Reactant 4

HCID 679Dimethyl SulfoxideHCID 8471TriethylamineHCID 65578Oxalyl chlorideHCID 67996268(9-ethyl-9H-carbazol-1-yl)methanol

Product 1

HCID 205204049-ethyl-9H-carbazole-1-carbaldehydeYield 90.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

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. stirringThe resulting solution was stirred at −78° C. for 5 hours
  2. stirringto stir an additional hour at −78° C
  3. customUpon completion, the reaction was quenched with water
  4. extractionextracted with DCM (3×50 mL)
  5. dry with materialCombined organic layers were dried over anhydrous sodium sulfate
  6. filtrationfiltered off
  7. concentrationconcentrated on a rotary evaporator
  8. customThe residue was purified by a silica gel column chromatography
  9. washeluted with dichloromethane/methanol (50:1)

Sources & evidence

ORD record
ord-3f4b5fe1b59340d99c290e3f95eeb2d2
Source dataset
uspto-grants-2011_12
Patent number
US08080566B1

Reaction notes

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