Boron tribromide → 3-(2-Fluoro-4-hydroxyphenyl)-1-isopropyl-2,4-imidazolidinedione

HRID 482395Notes

Reaction equation

HRID 482395 reaction equation
B(Br)(Br)Br.[CH3:5][CH:6]([N:8]1[CH2:12][C:11](=[O:13])[N:10]([C:14]2[CH:19]=[CH:18][C:17]([O:20]C)=[CH:16][C:15]=2[F:22])[C:9]1=[O:23])[CH3:7]>C(Cl)Cl>[CH3:7][CH:6]([N:8]1[CH2:12][C:11](=[O:13])[N:10]([C:14]2[CH:19]=[CH:18][C:17]([OH:20])=[CH:16][C:15]=2[F:22])[C:9]1=[O:23])[CH3:5]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 189810291-(1-Methylethyl)-3-(2-fluoro-4-methoxy-phenyl)imidazolidin-2,4-dione

Product 1

HCID 189810733-(2-Fluoro-4-hydroxyphenyl)-1-isopropyl-2,4-imidazolidinedioneYield 61.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A 1M methylene chloride solution of boron tribromide (41.6 ml, 0.0416 mole) was cooled to -20° C. While this temperature was maintained, a solution of 5.55 g (0.0208 mole) of 1-(1-methylethyl)-3-(2-fluoro-4-methoxy-phenyl)imidazolidin-2,4-dione in 25 mL of methylene chloride was added to the reaction during an eight minute period. The reaction mixture was allowed to warm to room temperature, where it was stirred for approximately 17 hours. At the end of this time the reaction was poured over ice, and the resulting two-phase mixture was filtered. The organic phase was separated, dried over anhydrous magnesium sulfate, and filtered. The filtrate was evaporated under reduced pressure, leaving a black solid as a residue. This solid was recrystallized from ethyl acetate/petroleum ether, to yield 3.25 g of 1-(1-methylethyl)-3-(2-fluoro-4-hydroxyphenyl)imidazolidin-2,4-dione as a tan solid, m.p. 190°-192° C. The NMR and IR spectra were consistent with the proposed structure.

Workup

  1. temperatureWhile this temperature was maintained
  2. additionAt the end of this time the reaction was poured over ice
  3. filtrationthe resulting two-phase mixture was filtered
  4. customThe organic phase was separated
  5. dry with materialdried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customThe filtrate was evaporated under reduced pressure
  8. customleaving a black solid as a residue
  9. customThis solid was recrystallized from ethyl acetate/petroleum ether

Sources & evidence

ORD record
ord-fc2fb2ed02084d2b8c47b29fb00d1128
Source dataset
uspto-grants-1998_08
Patent number
US05798316

Reaction notes

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