Benzo(B)Thiophene-2-Boronic Acid → 2-(2-Pyridyl)benzothiophene

HRID 2076733Notes

Reaction equation

HRID 2076733 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.COCCOC.[S:14]1[C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][C:17]=2[CH:16]=[C:15]1B(O)O.C(=O)(O)[O-].[Na+]>C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.O>[S:14]1[C:15]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=2)=[CH:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][C:18]1=2

Participants

7

Reactant 4

HCID 2359Benzo(B)Thiophene-2-Boronic AcidHCID 79732-BromopyridineHCID 80711,2-DimethoxyethaneHCID 516892Sodium Bicarbonate

Product 1

HCID 115058532-(2-Pyridyl)benzothiophene

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolvent

Procedure

A two-necked 250 mL round-bottomed flask fitted with a reflux condenser (with gas inlet) and a rubber septum was flushed with argon before 2-bromopyridine (2.57 mL, 27 mmol) and ethyleneglycol dimethylether (80 mL, dry and degassed) were introduced. Tetrakis(triphenylphosphine)palladium (1.0 g, 0.87 mmol) was added and the solution stirred at room temperature for 10 minutes. Benzothiophene-2-boronic acid (5.0 g, 28.1 mmol) was then added, followed by anhydrous sodium bicarbonate (8.4 g. 100 mmol) and water (50 mL, degassed). The septum was replaced with a glass stopper and the reaction mixture was heated at 80° C. for 16 hours, cooled to room temperature and the volatiles removed in vacuo. Organics were extracted with ethyl acetate (3×100 mL), washed with brine and dried over magnesium sulfate. Removal of the organics yielded a pale yellow solid. Recrystallisation from ethanol yielded a colourless solid (3.9 g, 68%, two crops), m.p. 124-6° C.

Workup

  1. customA two-necked 250 mL round-bottomed flask fitted with a reflux condenser (with gas inlet)
  2. additionwere introduced
  3. temperaturethe reaction mixture was heated at 80° C. for 16 hours
  4. temperaturecooled to room temperature
  5. customthe volatiles removed in vacuo
  6. extractionOrganics were extracted with ethyl acetate (3×100 mL)
  7. washwashed with brine
  8. dry with materialdried over magnesium sulfate
  9. customRemoval of the
  10. customorganics yielded a pale yellow solid
  11. customRecrystallisation from ethanol
  12. customyielded a colourless solid (3.9 g, 68%, two crops), m.p. 124-6° C.

Sources & evidence

ORD record
ord-bb31e6320c33471ab89d245ee5827acd
Source dataset
uspto-grants-2011_04
Patent number
US07927717B2

Reaction notes

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