Hexachloroethane → 5-(5-Bromopyridin-2-yl)-2-chloro-4-ethyloxazole

HRID 1672575Notes

Reaction equation

HRID 1672575 reaction equation
[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[Br:11][C:12]1[CH:13]=[CH:14][C:15]([C:18]2[O:22][CH:21]=[N:20][C:19]=2[CH2:23][CH3:24])=[N:16][CH:17]=1.[Cl:25]C(Cl)(Cl)C(Cl)(Cl)Cl>C1COCC1.O>[Br:11][C:12]1[CH:13]=[CH:14][C:15]([C:18]2[O:22][C:21]([Cl:25])=[N:20][C:19]=2[CH2:23][CH3:24])=[N:16][CH:17]=1

Participants

6

Reactant 3

HCID 6214HexachloroethaneHCID 2733832Lithium HexamethyldisilazideHCID 666965965-(5-Bromopyridin-2-yl)-4-ethyloxazole

Product 1

HCID 666966195-(5-Bromopyridin-2-yl)-2-chloro-4-ethyloxazoleYield 89%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

LiHMDS (1.0 M in THF, 8.5 mL, 8.5 mmol) was added dropwise to a solution of Example 44A (1.97 g, 7.78 mmol) in THF (26 mL) at −78° C. After 30 min solid hexachloroethane (1.84 g, 7.78 mmol) was added in one portion and the reaction mixture was stirred while warming to ambient temperature overnight. The reaction was diluted with water and extracted with EtOAc. The organic extract was washed with water and brine, dried over Na2SO4, filtered, and concentrated in vacuo. Chromatography on silica gel (Analogix® Intelliflash 280™; SF25-120 g column; 100% hexane 0-5 min, then 0% to 25% EtOAc/hexanes eluant, 5-40 min) afforded 1.99 g (89%) of the title compound as a yellow oil that solidified on standing. 1H NMR (300 MHz, CDCl3) δ 8.67 (dd, J=2.4, 0.6, 1H), 7.86 (dd, J=8.5, 2.4, 1H), 7.47 (dd, J=8.5, 0.6, 1H), 3.02 (q, J=7.5, 2H), 1.27 (t, J=7.5, 3H). MS (DCI+) m/z 287/289 (M+H).

Workup

  1. extractionextracted with EtOAc
  2. extractionThe organic extract
  3. washwas washed with water and brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-c70990ba134a4ae9ab58b49d81870bfe
Source dataset
uspto-grants-2011_08
Patent number
US07998993B2

Reaction notes

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