Benzo(B)Thiophene-2-Boronic Acid → 3-Phenylbenzothiophene

HRID 590960Notes

Reaction equation

HRID 590960 reaction equation
[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1B(O)O.I[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C(=O)([O-])[O-].[Na+].[Na+]>C(O)C.C1(C)C=CC=CC=1.O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Pd]>[C:14]1([C:3]2[C:4]3[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=3[S:1][CH:2]=2)[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

8

Reactant 3

HCID 2359Benzo(B)Thiophene-2-Boronic AcidHCID 10340Sodium CarbonateHCID 11575Iodobenzene

Product 1

HCID 6108813-PhenylbenzothiopheneYield 112.2%

Reagents, catalysts & solvents 4

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 702EthanolSolventHCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

A solution of benzothiopheneboronic acid (1 g, 5.61 mmol) in ethanol (23 mL) was added to a mixture of iodobenzene (560 μL, 5 mmol), palladium tetrakis(triphenylphosphine) (460 mg, 0.4 mmol) and sodium carbonate (2.38 g, 22.4 mmol) in a mixture of toluene (15 mL) and water (15 mL). The reaction mixture was refluxed for 6 hours and then concentrated in vacuo. The residue was partitioned between ethyl acetate (30 mL) and water (10 mL). The biphasic mixture was acidified with an aqueous solution of hydrochloric acid 1N until pH 2. The aqueous layer was extracted with ethyl acetate (2×20 mL) and the organic layer was washed with water (10 mL), brine (10 mL), dried over sodium sulfate, filtered and evaporated to dryness. The residue was purified by flash chromatography on silica gel (cyclohexane) to afford the desired product (3a) as a yellow solid (1.18 g, 5.61 mmol, 100%).

Workup

  1. temperatureThe reaction mixture was refluxed for 6 hours
  2. concentrationconcentrated in vacuo
  3. customThe residue was partitioned between ethyl acetate (30 mL) and water (10 mL)
  4. extractionThe aqueous layer was extracted with ethyl acetate (2×20 mL)
  5. washthe organic layer was washed with water (10 mL), brine (10 mL)
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. customevaporated to dryness
  9. customThe residue was purified by flash chromatography on silica gel (cyclohexane)

Sources & evidence

ORD record
ord-9bed46755c3046528d001721d536659c
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Reaction notes

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