1,3-Dibromo-5,5-dimethylhydantoin → 5-Bromo-2,3-dihydro-7-azaindole

HRID 2068027Notes

Reaction equation

HRID 2068027 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][N:8]=2)[CH2:3][CH2:2]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[Br:22]N1C(C)(C)C(=O)N(Br)C1=O>C(Cl)Cl>[Br:22][C:6]1[CH:5]=[C:4]2[C:9](=[N:8][CH:7]=1)[NH:1][CH2:2][CH2:3]2

Participants

5

Reactant 3

HCID 64791,3-Dibromo-5,5-dimethylhydantoinHCID 521998p-Toluenesulfonic acid monohydrateHCID 100118891H,2H,3H-pyrrolo(2,3-b)pyridine

Product 1

HCID 219640795-Bromo-2,3-dihydro-7-azaindoleYield 86.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of 7-azaindoline (22.7 g, 189 mmol), p-toluene sulphonic acid monohydrate (2.95 g, 15 mmol) and 1,3-dibromo-5,5-dimethylhydantoin (27.4 g, 96 mmol) in methylene chloride (1500 μl) was stirred at ambient temperature for 3 hours. The reaction solution was then decanted from a black polymeric material; washed with 0.2 M sodium thiosulphate (4×250 mls) followed by brine and dried over magnesium sulphate. The filtrate was evaporated under vacuum to give a black solid which was extracted with boiling ethyl acetate (2×800 mls and 2×500 mls). The combined extracts were heated at reflux for a few minutes with decolorizing charcoal, filtered and evaporated under vacuum to give 5-bromo-7-azaindoline (16.6 g, 44%).

Workup

  1. customThe reaction solution was then decanted from a black polymeric material
  2. washwashed with 0.2 M sodium thiosulphate (4×250 mls)
  3. dry with materialdried over magnesium sulphate
  4. customThe filtrate was evaporated under vacuum
  5. customto give a black solid which
  6. extractionwas extracted with boiling ethyl acetate (2×800 mls and 2×500 mls)
  7. temperatureThe combined extracts were heated
  8. temperatureat reflux for a few minutes with decolorizing charcoal
  9. filtrationfiltered
  10. customevaporated under vacuum

Sources & evidence

ORD record
ord-9039772562444258aa64f336ce2846c2
Source dataset
uspto-grants-2012_10
Patent number
US08293902B2

Reaction notes

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