Boron trifluoride → 1-(Oxan-2-yl)-4,5-diphenyl-1H-imidazole

HRID 1449401Notes

Reaction equation

HRID 1449401 reaction equation
[C:1]1([C:7]2[N:8]=[CH:9][NH:10][C:11]=2[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[O:18]1[CH:23]=[CH:22][CH2:21][CH2:20][CH2:19]1.C(OCC)(=O)C.B(F)(F)F>CCOCC>[C:1]1([C:7]2[N:8]=[CH:9][N:10]([CH:19]3[CH2:20][CH2:21][CH2:22][CH2:23][O:18]3)[C:11]=2[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

6

Reactant 4

HCID 6356Boron trifluorideHCID 80803,4-dihydro-2H-pyranHCID 8857Ethyl AcetateHCID 695884,5-Diphenylimidazole

Product 1

HCID 135081561-(Oxan-2-yl)-4,5-diphenyl-1H-imidazole

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A mixture of 27 g (0.122 mole) 4,5-diphenylimidazole, 21 g (0.25 mole) dihydropyran, 250 ml ethyl acetate and 4.0 g BF3. Et2O was refluxed for five days. The nearly clear solution was diluted with ether and filtered to remove 0.6 g insoluble starting material. The ether filtrate was washed several times with 10% NaHCO3 then dried and evaporated. TLC showed starting material still present, so the crude product was chromatographed on 2 lb SilicAR CC-7, eluting with toluene containing 20 to 40% ethyl acetate. The pure 4,5-diphenyl-1-(2-tetrahydropyranyl)imidazole thus obtained weighed 30.3 g (82%) and had m.p. 170°-171°.

Workup

  1. filtrationfiltered
  2. customto remove 0.6 g
  3. washThe ether filtrate was washed several times with 10% NaHCO3
  4. customthen dried
  5. customevaporated
  6. customso the crude product was chromatographed on 2 lb SilicAR CC-7
  7. washeluting with toluene containing 20 to 40% ethyl acetate

Sources & evidence

ORD record
ord-21b78627712d4597a5649d9fd20e5032
Source dataset
uspto-grants-1980_02
Patent number
US04190666

Reaction notes

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