Ethylene Glycol → 5'-Bromospiro[1,3-dioxolane-2,3'-[3H]indol]-2'(1'H)-one

HRID 1052952

Reaction equation

HRID 1052952 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]2=[O:12].[CH2:13](O)[CH2:14][OH:15].CC1C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]12[O:15][CH2:14][CH2:13][O:12]1

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 68895-Bromoisatin

Product 1

HCID 27329225'-Bromospiro[1,3-dioxolane-2,3'-[3H]indol]-2'(1'H)-oneYield 87.4%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A magnetically stirred solution of 5-bromoindoline-2,3-dione (226 g, 1.0 mol, 1 eq.), ethylene glycol (186 g, 3.0 mol, 3 eq.), p-TSA (30 g, 0.16 mol, 16 mol %) and toluene (1500 mL) was refluxed overnight using a Dean-Stark apparatus. After total consumption of 5-bromoindoline-2,3-dione, EtOAc (1500 mL) and water (1000 mL) were added to remove excess of diol. The aqueous layer was extracted twice with EtOAc (500 mL). The collected organic layers were collected, dried over Na2SO4, filtered and concentrated under reduced pressure. The yellowish solid was washed with diethyl ether to give the desired compound as a pale yellow solid (236 g, 87%). 1H NMR (400 MHz, DMSO-d6): δH 10.56 (s, 1H), 7.31-7.33 (m, 2H), 6.93 (d, J=8.0 Hz, 1H), 4.27-4.35 (m, 4H), 2.35 (s, 3H), 2.18 (s, 3H). MS (ESI) m/e [M+1]+ 270, 272.

Workup

  1. customAfter total consumption of 5-bromoindoline-2,3-dione, EtOAc (1500 mL) and water (1000 mL)
  2. additionwere added
  3. customto remove excess of diol
  4. extractionThe aqueous layer was extracted twice with EtOAc (500 mL)
  5. customThe collected organic layers were collected
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure
  9. washThe yellowish solid was washed with diethyl ether

Sources & evidence

ORD record
ord-d6519d0f762d455da3d0504d66c1d37f
Source dataset
uspto-grants-2016_07
Patent number
US09393232B2

Linked notes

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