Monobasic potassium phosphate → tert-butyl 4-bromo-3-{[(2,2,2-trichloroethoxy)carbonyl]amino}-1H-pyrazole-1-carboxylate

HRID 1744129Notes

Reaction equation

HRID 1744129 reaction equation
[Cl:1][C:2]([Cl:30])([Cl:29])[CH2:3][O:4][C:5]([N:7](C(OCC(Cl)(Cl)Cl)=O)[C:8]1[C:12]([Br:13])=[CH:11][N:10]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[N:9]=1)=[O:6].OP([O-])(O)=O.[K+]>C1COCC1.[Zn]>[Br:13][C:12]1[C:8]([NH:7][C:5]([O:4][CH2:3][C:2]([Cl:29])([Cl:1])[Cl:30])=[O:6])=[N:9][N:10]([C:14]([O:16][C:17]([CH3:19])([CH3:20])[CH3:18])=[O:15])[CH:11]=1

Participants

5

Reactant 2

HCID 516951Monobasic potassium phosphateHCID 22235896HCID 22235896, compound

Product 1

HCID 22235916tert-butyl 4-bromo-3-{[(2,2,2-trichloroethoxy)carbonyl]amino}-1H-pyrazole-1-carboxylate

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To tert-butyl 3-{bis[(2,2,2-trichloroethoxy)carbonyl]amino}-4-bromo-1H-pyrazole-1-carboxylate (12.7 g, 20.73 mmol) in THF (200 mL) was added activated zinc powder (13.5 g, 207.3 mmol) followed by an aqueous solution of KH2PO4 (1.0 M, 41.5 mL, 41.5 mmol) dropwise and the reaction was stirred for 3 hours at rt. The zinc powder was filtered off, rinsed with Et2O and water, the aqueous phase extracted with Et2O (2×), and the combined organics dried over Na2SO4, concentrated in vacuo and purified by flash chromatography over silica gel (EtOAc/Hex, 2/8) to afford tert-butyl 4-bromo-3-{[(2,2,2-trichloroethoxy)carbonyl]amino }-1H-pyrazole-1-carboxylate.

Workup

  1. filtrationThe zinc powder was filtered off
  2. washrinsed with Et2O and water
  3. extractionthe aqueous phase extracted with Et2O (2×)
  4. dry with materialthe combined organics dried over Na2SO4
  5. concentrationconcentrated in vacuo
  6. custompurified by flash chromatography over silica gel (EtOAc/Hex, 2/8)

Sources & evidence

ORD record
ord-8e61b177c1e14a8a9f8750a0b34dd1b5
Source dataset
uspto-grants-2006_03
Patent number
US07012075B2

Reaction notes

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