4,6-Dichloro-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one → HCID 485911, compound

HRID 363349Notes

Reaction equation

HRID 363349 reaction equation
Br[C:2](Br)=[CH:3][C:4]1[O:5][CH:6]=[CH:7][CH:8]=1.C([Li])CCC.Cl[C:16]1([C:28]([F:31])([F:30])[F:29])[C:21]2[CH:22]=[C:23]([Cl:26])[CH:24]=[CH:25][C:20]=2[NH:19][C:18](=[O:27])[O:17]1>C1COCC1>[Cl:26][C:23]1[CH:24]=[CH:25][C:20]2[NH:19][C:18](=[O:27])[O:17][C:16]([C:2]#[C:3][C:4]3[O:5][CH:6]=[CH:7][CH:8]=3)([C:28]([F:29])([F:30])[F:31])[C:21]=2[CH:22]=1

Participants

5

Reactant 3

HCID 98823264,6-Dichloro-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-oneHCID 108579432-(2,2-Dibromovinyl)furanHCID 178418339Butyllithium

Product 1

HCID 485911HCID 485911, compoundYield 110.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5.9 g (25 mmoles) of 1,1-dibromo-2-(furan-2-yl)ethylene in 124 mL of anhydrous THF at -20° was added dropwise 31.0 mL of 1.6M n-butyllithium in hexanes (50 mmoles). This solution was allowed to warm to ambient temperature over a period of 30 min, after which time it was cooled to -50°. 4,6-Dichloro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one (2.65 g, 9.27 mmoles) was added in one portion, and the resulting solution was allowed to warm to -35° over 40 min. The reaction was quenched by the addition of aqueous ammonium chloride, and this mixture was poured onto water and extracted twice with ethyl acetate. The combined extracts were washed with brine, dried over sodium sulfate, and evaporated. The crude product was purified by column chromatography on silica gel (elution with 15% and 30% ethyl acetate in hexanes) affording 3.5 g of a solid which was recrystallized from ethyl acetate/hexanes to afford 3.03 g (95.7%) of the title compound.

Workup

  1. temperatureafter which time it was cooled to -50°
  2. temperatureto warm to -35° over 40 min
  3. customThe reaction was quenched by the addition of aqueous ammonium chloride
  4. additionthis mixture was poured onto water
  5. extractionextracted twice with ethyl acetate
  6. washThe combined extracts were washed with brine
  7. dry with materialdried over sodium sulfate
  8. customevaporated
  9. customThe crude product was purified by column chromatography on silica gel (elution with 15% and 30% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-3239807dba99490d936182b0594990f5
Source dataset
uspto-grants-1999_02
Patent number
US05874430

Reaction notes

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