Cyclopentene → 2-Amino-5-bromo-3-cyclopent-2-en-1-ylbenzenesulphonic acid

HRID 1599176Notes

Reaction equation

HRID 1599176 reaction equation
[NH2:1][C:2]1[C:7](I)=[CH:6][C:5]([Br:9])=[CH:4][C:3]=1[S:10]([OH:13])(=[O:12])=[O:11].[CH:14]1[CH2:18][CH2:17][CH2:16][CH:15]=1.C([O-])(=O)C.[K+].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>CN(C)C=O.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[NH2:1][C:2]1[C:7]([CH:18]2[CH2:17][CH2:16][CH:15]=[CH:14]2)=[CH:6][C:5]([Br:9])=[CH:4][C:3]=1[S:10]([OH:13])(=[O:12])=[O:11]

Participants

7

Reactant 4

HCID 8882CyclopenteneHCID 11776TriphenylphosphineHCID 517044Potassium AcetateHCID 189193852-Amino-5-bromo-3-iodobenzenesulphonic acid

Product 1

HCID 189316652-Amino-5-bromo-3-cyclopent-2-en-1-ylbenzenesulphonic acid

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

A mixture containing 30 g (79.4 mmol) of 2-amino-5-bromo-3-iodobenzenesulphonic acid, 35 ml (397 mmol) of cyclopentene, 19.5 g (199 mmol) of potassium acetate, 6.24 g (23.8 mmol) of triphenylphosphine and 2.67 g (11.9 mmol) of palladium (II) acetate in 160 ml of N,N-dimethylformamide is heated at 80° C. for 48 hours, under a nitrogen atmosphere. The reaction medium is then concentrated under reduced pressure and the residue is taken up in a mixture containing 200 ml of methanol, 200 ml of 1N hydrochloric acid and 10 ml of 95% sulphuric acid solution. The mixture is evaporated again under reduced pressure and filtered, and the precipitate thus obtained is purified by chromatography on an RP 18 reverse-phase column, eluting with an acetonitrile/water mixture (3:7). The residue is recrystallized from a methanol/pentane mixture.

Workup

  1. concentrationThe reaction medium is then concentrated under reduced pressure
  2. additioncontaining 200 ml of methanol, 200 ml of 1N hydrochloric acid and 10 ml of 95% sulphuric acid solution
  3. customThe mixture is evaporated again under reduced pressure
  4. filtrationfiltered
  5. customthe precipitate thus obtained
  6. customis purified by chromatography on an RP 18 reverse-phase column
  7. washeluting with an acetonitrile/water mixture (3:7)
  8. customThe residue is recrystallized from a methanol/pentane mixture

Sources & evidence

ORD record
ord-de0c6264c4404f468726b5e9ddb88a40
Source dataset
uspto-grants-1998_04
Patent number
US05739382

Reaction notes

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