1,10-Phenanthroline → 2-(5-Bromo-2-pyridinyl)benzoxazole

HRID 521547

Reaction equation

HRID 521547 reaction equation
Br[C:2]1[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=1[NH2:4].[Br:9][C:10]1[CH:11]=[CH:12][C:13]([C:16](Cl)=[O:17])=[N:14][CH:15]=1.C([O-])([O-])=O.[Cs+].[Cs+].N1C2C(=CC=C3C=2N=CC=C3)C=CC=1>[Cu]I.C(Cl)Cl.O1CCOCC1>[Br:9][C:10]1[CH:11]=[CH:12][C:13]([C:16]2[O:17][C:2]3[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=3[N:4]=2)=[N:14][CH:15]=1

Participants

8

Reactant 4

HCID 13181,10-PhenanthrolineHCID 10796Cesium carbonateHCID 119922-BromoanilineHCID 190907715-Bromo-pyridine-2-carbonyl chloride

Product 1

HCID 469416132-(5-Bromo-2-pyridinyl)benzoxazoleYield 30%

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of 2-bromoaniline (3.90 g, 22.7 mmol), 5-bromopyridine-2-carbonyl chloride (5.00 g, 22.7 mmol), Cs2CO3 (14.78 g, 45.36 mmol), 1,10-phenanthroline (0.409 g, 2.27 mmol), CuI (0.216 g, 1.13 mmol) and anhydrous 1,4-dioxane (40 mL) was degassed with argon for about 40 min while stirring. The stirring reaction mixture was then maintained under argon at about 120° C. for about 40 h. Upon completion, the reaction was cooled to RT and poured over CH2Cl2 (300 mL). The organics were then washed with sat. NaHCO3, H2O and brine, dried over MgSO4, filter and concentrated in vacuo. Purification of the crude product via flash chromatography (SiO2, 4:1 dichloromethane-hexanes) and subsequent recrystallization from hexanes afforded compound 11 (1.86 g, 30% yield) as colorless fibers.

Workup

  1. customwas degassed with argon for about 40 min
  2. customThe stirring reaction mixture
  3. temperatureUpon completion, the reaction was cooled to RT
  4. washThe organics were then washed with sat. NaHCO3, H2O and brine
  5. dry with materialdried over MgSO4
  6. filtrationfilter
  7. concentrationconcentrated in vacuo
  8. customPurification of the crude product

Sources & evidence

ORD record
ord-3c0af32c96b544d6aa712ca19029fe13
Source dataset
uspto-grants-2016_05
Patent number
US09328086B2

Linked notes

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