Indole → 3-(1,4-Dioxaspiro[4.5]dec-7-en-8-yl)-1H-indole

HRID 1250150Notes

Reaction equation

HRID 1250150 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.[CH2:10]1[O:20][C:13]2([CH2:18][CH2:17][C:16](=O)[CH2:15][CH2:14]2)[O:12][CH2:11]1.[OH-].[K+]>CO>[O:12]1[C:13]2([CH2:18][CH2:17][C:16]([C:3]3[C:4]4[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=4)[NH:1][CH:2]=3)=[CH:15][CH2:14]2)[O:20][CH2:10][CH2:11]1

Participants

5

Reactant 3

HCID 798IndoleHCID 14797Potassium HydroxideHCID 5674151,4-Dioxaspiro[4.5]decan-8-one

Product 1

HCID 27638573-(1,4-Dioxaspiro[4.5]dec-7-en-8-yl)-1H-indoleYield 90%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
23 °C

Procedure

Indole (22.6 g, 190 mmol), 1,4-cyclohexanedione monoethylene ketal (22.8 g, 145 mmol) and KOH (4.6 g, 80 mmol) were heated to reflux in 50 mL of MeOH for 6 h. The reaction mixture was cooled to 23° C., a solid precipitated and was collected by vacuum filtration. This solid was washed with 3×30 mL of H2O to give 33.3 g (130.5 mmol, a 90% yield) of the title compound as a white solid. MS (ES) m/z (relative intensity): 256 (M++H, 100).

Workup

  1. customa solid precipitated
  2. filtrationwas collected by vacuum filtration
  3. washThis solid was washed with 3×30 mL of H2O
  4. customto give 33.3 g (130.5 mmol

Sources & evidence

ORD record
ord-8ee2c402a0e74599b5ae73570fb66beb
Source dataset
uspto-grants-2002_01
Patent number
US06337326B1

Reaction notes

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