Triphenylphosphine → 7-[2-(1H-1-Imidazolyl)ethoxy]-4-chromanone

HRID 368347Notes

Reaction equation

HRID 368347 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1.[N:13]1([CH2:18][CH2:19]O)[CH:17]=[CH:16][N:15]=[CH:14]1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>C1COCC1.CCOC(C)=O>[N:13]1([CH2:18][CH2:19][O:1][C:2]2[CH:11]=[C:10]3[C:5]([C:6](=[O:12])[CH2:7][CH2:8][O:9]3)=[CH:4][CH:3]=2)[CH:17]=[CH:16][N:15]=[CH:14]1

Participants

7

Reactant 4

HCID 11776TriphenylphosphineHCID 74168N-(2-Hydroxyethyl)imidazoleHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 108558177-hydroxy-2,3-dihydro-4H-chromen-4-one

Product 1

HCID 186264697-[2-(1H-1-Imidazolyl)ethoxy]-4-chromanoneYield 29.7%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

Under N2, a solution of 2.0 g (0.012 mol) of 7-hydroxy-4-chromanone (J. Org. Chem., 1994;59:1216) in 25 mL of THF was treated with 1.29 g (0.013 mol) of 2-(1H-1-imidazolyl)-1-ethanol and 3.15 g (0.012 mol) of triphenylphosphine. The solution was cooled in ice and treated over 10 minutes with a solution of 1.89 mL (0.012 mol) of diethyl azodicarboxylate in 5.0 mL of THF. After stirring at room temperature for 3 days, the solution was diluted with EtOAc and washed with saturated NaCl. Drying over MgSO4 and removal of the solvent under reduced pressure left the crude product. Chromatography on silica gel, eluting with a gradient of CHCl3 to CHCl3 /MeOH (96/4) gave the product which was recrystallized from EtOAc/hexane to give 0.92 g (29.7% yield) of a white solid, mp 128-130° C. The structure was confirmed by NMR and mass spectroscopy. MS m/z 259 (M+H+).

Workup

  1. temperatureThe solution was cooled in ice
  2. washwashed with saturated NaCl
  3. dry with materialDrying over MgSO4 and removal of the solvent under reduced pressure
  4. waitleft the crude product
  5. washChromatography on silica gel, eluting with a gradient of CHCl3 to CHCl3 /MeOH (96/4)
  6. customgave the product which
  7. customwas recrystallized from EtOAc/hexane

Sources & evidence

ORD record
ord-88413264a4b64f9db3bf58fd59157964
Source dataset
uspto-grants-2000_10
Patent number
US06133303

Reaction notes

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