Ammonium Chloride → tert-butyl N-(3-bromo-2,6-dimethylpyrazolo[5,1-b][1,3]thiazol-7-yl)carbamate

HRID 41261

Reaction equation

HRID 41261 reaction equation
[C:1]([O:5][C:6](=[O:18])[NH:7][C:8]1[C:9]([CH3:17])=[N:10][N:11]2[CH:15]=[C:14]([CH3:16])[S:13][C:12]=12)([CH3:4])([CH3:3])[CH3:2].C([Li])CCC.[Br:24]C(F)(F)C(F)(F)Br.[Cl-].[NH4+]>O1CCCC1>[C:1]([O:5][C:6](=[O:18])[NH:7][C:8]1[C:9]([CH3:17])=[N:10][N:11]2[C:15]([Br:24])=[C:14]([CH3:16])[S:13][C:12]=12)([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 313011,2-Dibromo-1,1,2,2-tetrafluoroethaneHCID 58223486tert-butyl N-(2,6-dimethylpyrazolo[5,1-b][1,3]thiazol-7-yl)carbamateHCID 178418339Butyllithium

Product 1

HCID 58223468tert-butyl N-(3-bromo-2,6-dimethylpyrazolo[5,1-b][1,3]thiazol-7-yl)carbamateYield 58.9%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A tetrahydrofuran (10 mL) solution of tert-butyl(2,6-dimethylpyrazolo[5,1-b][1,3]thiazol-7-yl)carbamate (266 mg, 0.995 mmol) was cooled to −78° C., and n-butyllithium (2.64M, 0.829 mL, 2.19 mmol) was added dropwise and the mixture was stirred for 10 minutes. Then, 1,2-dibromotetrafluoroethane (0.142 ml, 1.19 mmol) was added to the mixture, and the reaction mixture was warmed to room temperature and stirred at room temperature over one day and night. To the reaction mixture, a saturated aqueous solution of ammonium chloride was added, and a substance of interest was extracted with ethyl acetate. The organic layer was washed with brine and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by medium pressure silica gel column chromatography (n-heptane/ethyl acetate: 3/1 then 2/1) to obtain the title compound (203 mg, 0.586 mmol).

Workup

  1. stirringstirred at room temperature over one day and night
  2. extractiona substance of interest was extracted with ethyl acetate
  3. washThe organic layer was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. distillationthe solvent was distilled off under reduced pressure
  6. customThe residue was purified by medium pressure silica gel column chromatography (n-heptane/ethyl acetate

Sources & evidence

ORD record
ord-eabec0c259374d63b5b3aa99f9108ff7
Source dataset
uspto-grants-2013_09
Patent number
US08530504B2

Linked notes

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