Hexane → tert-butyl N-(7-bromo-2-ethylpyrazolo[1,5-a]pyridin-3-yl)-N-cyclopropylmethylcarbamate

HRID 347874Notes

Reaction equation

HRID 347874 reaction equation
C([Li])CCC.CCCCCC.[CH:12]1([CH2:15][N:16]([C:24]2[C:25]([CH2:33][CH3:34])=[N:26][N:27]3[CH:32]=[CH:31][CH:30]=[CH:29][C:28]=23)[C:17](=[O:23])[O:18][C:19]([CH3:22])([CH3:21])[CH3:20])[CH2:14][CH2:13]1.[Br:35]C(F)(F)C(F)(F)Br.C(=O)(O)[O-].[Na+]>O1CCCC1>[Br:35][C:32]1[N:27]2[N:26]=[C:25]([CH2:33][CH3:34])[C:24]([N:16]([CH2:15][CH:12]3[CH2:13][CH2:14]3)[C:17](=[O:23])[O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[C:28]2[CH:29]=[CH:30][CH:31]=1

Participants

7

Reactant 5

HCID 8058HexaneHCID 313011,2-Dibromo-1,1,2,2-tetrafluoroethaneHCID 516892Sodium BicarbonateHCID 21084192tert-butyl N-cyclopropylmethyl-N-(2-ethylpyrazolo[1,5-a]pyridin-3-yl)carbamateHCID 178418339Butyllithium

Product 1

HCID 21084186tert-butyl N-(7-bromo-2-ethylpyrazolo[1,5-a]pyridin-3-yl)-N-cyclopropylmethylcarbamateYield 87.9%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of n-butyllithium in hexane (1.6M, 3.88 mL, 6.18 mmol) was added dropwise to a solution of tert-butyl N-cyclopropylmethyl-N-(2-ethylpyrazolo[1,5-a]pyridin-3-yl)carbamate (1.5 g, 4.76 mmol) in tetrahydrofuran (15 mL) at −70° C. After stirring the reaction mixture for 50 minutes at the same temperature, 1,2-dibromotetrafluoroethane (1.0 mL, 8.33 mmol) was added dropwise to the reaction mixture. The temperature of the reaction mixture was slowly increased and aqueous sodium bicarbonate was added at 0° C. The reaction mixture was extracted with ethyl acetate, and the organic extract was washed with brine, dried over magnesium sulfate and evaporated. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=8:1) to afford 1.65 g of the title compound as a yellow oil (87.8% yield).

Workup

  1. additionwas added dropwise to the reaction mixture
  2. temperatureThe temperature of the reaction mixture was slowly increased
  3. extractionThe reaction mixture was extracted with ethyl acetate
  4. extractionthe organic extract
  5. washwas washed with brine
  6. dry with materialdried over magnesium sulfate
  7. customevaporated
  8. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=8:1)

Sources & evidence

ORD record
ord-394f655c183e413bb54690dd5f0ef94d
Source dataset
uspto-grants-2007_02
Patent number
US07176216B2

Reaction notes

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