Boron trifluoride etherate → HCID 13050566, compound

HRID 2050037Notes

Reaction equation

HRID 2050037 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:9]=[CH:10][NH:11][C:12]=2[C:13]2[CH:18]=[CH:17][C:16]([F:19])=[CH:15][CH:14]=2)=[CH:4][CH:3]=1.[O:20]1[CH:25]=[CH:24][CH2:23][CH2:22][CH2:21]1.B(F)(F)F.CCOCC.C(OCC)(=O)C>CCOCC.B(F)(F)F.CCOCC>[F:19][C:16]1[CH:17]=[CH:18][C:13]([C:12]2[N:11]=[CH:10][N:9]([CH:21]3[CH2:22][CH2:23][CH2:24][CH2:25][O:20]3)[C:8]=2[C:5]2[CH:4]=[CH:3][C:2]([F:1])=[CH:7][CH:6]=2)=[CH:14][CH:15]=1

Participants

7

Reactant 4

HCID 8000Boron trifluoride etherateHCID 80803,4-dihydro-2H-pyran2×HCID 8857Ethyl Acetate2×HCID 10848647HCID 10848647, compound

Product 1

HCID 13050566HCID 13050566, compoundYield 85.1%

Reagents, catalysts & solvents 2

HCID 8000Boron trifluoride etherateCatalystHCID 3283Diethyl EtherSolvent

Procedure

A mixture of 124 g (0.484 mole) of 4,5-bis(4-fluorophenyl)imidazole, 84 g (1.0 mole) dihydropyran, 20 g boron trifluoride etherate and 1 l ethyl acetate was heated at reflux over a weekend. Analysis by TLC (ethyl acetate) showed the presence of some unchanged starting material, so 20 g (~0.24 mole) of dihydropyran and 5 g boron trifluoride etherate was added and heating was continued overnight. The mixture was then diluted with 1 l ether and washed with 10% sodium bicarbonate solution (3×1 l). The organic layer was dried and concentrated on a rotary evaporator. The residual solid was recrystallized from methylcyclohexane (removing some insoluble starting material by filtration) to give 140.2 g (85%) of 4,5-bis(4-fluorophenyl)-1-(2-tetrahydropyranyl)imidazole as a white solid, mp 149°-152°. F-NMR indicated purity ~95%. A smaller run was chromatographed to give pure material mp 158°-9°. IR: 3.25μ (=CH); 3.38, 3.49μ (sat. CH); 6.22, 6.28, 6.41, 6.60, 6.69μ (C=C and/or C=N); 8.20μ (CF); 9μ region (C--O--C). H-NMR: m(1.4-2.1 δ, 6H); m (3.4 δ,1H); m (4.0 δ, 1H); m (4.7 δ, 1H); m (6.6-7.5 δ, 8H); s (7.8 δ, 1H). F-NMR: two multiplets (112.4 δ and 116.5 δ, each decouples to a singlet).

Workup

  1. temperaturewas heated
  2. temperatureat reflux over a weekend
  3. additionwas added
  4. temperatureheating
  5. washwashed with 10% sodium bicarbonate solution (3×1 l)
  6. customThe organic layer was dried
  7. concentrationconcentrated on a rotary evaporator
  8. customThe residual solid was recrystallized from methylcyclohexane (
  9. customremoving
  10. filtrationby filtration)

Sources & evidence

ORD record
ord-41086a16f5e6425b86a3cc13d95be523
Source dataset
uspto-grants-1980_04
Patent number
US04199592

Reaction notes

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